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| f part number 45005-00-eng revision c may 2002 acutime ? 2000 synchronization kit user guide www.datasheet.co.kr datasheet pdf - http://www..net/
corporate office trimble navigation limited timing and synchronization group 645 north mary avenue post office box 3642 sunnyvale, ca 94088-3642 u.s.a. phone: +1-408-481-8940, 1-800-545-7762 fax: +1-408-481-7744 www.trimble.com support offices trimble navigation europe limited trimble house, meridian office park osborn way, hook hampshire rg27 9hx england +44-1256-760-150 fax: +44-1256-760-148 voicemail: +44-1256-761-130 trimble navigation singapore pte limited 79 anson road # 05-02 singapore 079906 singapore +65-325-5668 fax: +65-225-9989 voicemail: +65-325-5668 trimble japan k.k. sumitomo hamamatsu-cho, building 10f 1-18-16 hamamatsu-cho minato-ku tokyo 105 japan +81-3-5472-0880 fax: +81-3-5472-2326 trimble navigation australia pty limited p.o. box 769 spring hill qld 4004 australia +61-7-3216-0044 fax: +61-7-3216-0088 copyright and trademarks ? 2002, trimble navigation limited. all rights reserved. no part of this manual may be copied, reproduced, translated, or reduced to any electronic medium or machine-readable form for any use other than with the acutime? 2000 gps smart antenna, or acutime 2000 synchronization kit . the sextant logo with trimble is a trademark of trimble navigation limited, registered in the united states patent and trademark office. the globe & triangle logo, trimble, and acutime are trademarks of trimble navigation limited. all other trademarks are the property of their respective owners. release notice this is the may 2002 release (revision c) of the acutime 2000 synchronization kit user guide, part number 45005-00-eng. it applies to the acutime ? 2000 synchronization kit software. the following limited warranties give you specific legal rights. you may have others, which vary from state/jurisdiction to state/jurisdiction. hardware limited warranty trimble warrants that this trimble hardware product (the ?product?) shall be free from defects in materials and workmanship and will substantially conform to trimble?s applicable published specifications for the product for a period of one (1) year, starting from the date of delivery. the warranty set forth in this paragraph shall not apply to software/firmware products. www.datasheet.co.kr datasheet pdf - http://www..net/ software and firmware license, limited warranty this trimble software and/or firmware product (the ?software?) is licensed and not sold. its use is governed by the provisions of the applicable end user license agreement (?eula?), if any, included with the software. in the absence of a separate eula included with the software providing different limited warranty terms, exclusions, and limitations, the following terms and conditions shall apply. trimble warrants that this trimble software product will substantially conform to trimble?s applicable published specifications for the software for a period of ninety (90) days, starting from the date of delivery. warranty remedies trimble's sole liability and your exclusive remedy under the warranties set forth above shall be, at trimble?s option, to repair or replace any product or software that fails to conform to such warranty (?nonconforming product?), or refund the purchase price paid by you for any such nonconforming product, upon your return of any nonconforming product to trimble in accordance with trimble?s standard return material authorization procedures. warranty exclusions and disclaimer these warranties shall be applied only in the event and to the extent that: (i) the products and software are properly and correctly installed, configured, interfaced, maintained, stored, and operated in accordance with trimble?s relevant operator's manual and specifications, and; (ii) the products and software are not modified or misused. the preceding warranties shall not apply to, and trimble shall not be responsible for defects or performance problems resulting from (i) the combination or utilization of the product or software with products, information, data, systems or devices not made, supplied or specified by trimble; (ii) the operation of the product or software under any specification other than, or in addition to, trimble's standard specifications for its products; (iii) the unauthorized modification or use of the product or software; (iv) damage caused by accident, lightning or other electrical discharge, fresh or salt water immersion or spray; or (v) normal wear and tear on consumable parts (e.g., batteries). the warranties above state trimble ' s entire liability , and your exclusive remedies , relating to performance of the products and software . except as otherwise expressly provided herein , the products , software , and accompanying documentation and materials are provided ? as - is ? and without express or implied warranty of any kind by either trimble navigation limited or anyone who has been involved in its creation , production , installation , or distribution , including , but not limited to , the implied warranties of merchantability and fitness for a particular purpose , title , and noninfringement . the stated express warranties are in lieu of all obligations or liabilities on the part of trimble arising out of , or in connection with , any products or software . some states and jurisdictions do not allow limitations on duration or the exclusion of an implied warranty , so the above limitation may not apply to you . www.datasheet.co.kr datasheet pdf - http://www..net/ trimble navigation limited is not responsible for the operation or failure of operation of gps satellites or the availability of gps satellite signals . limitation of liability trimble ? s entire liability under any provision herein shall be limited to the greater of the amount paid by you for the product or software license or u . s .$25.00. to the maximum extent permitted by applicable law , in no event shall trimble or its suppliers be liable for any indirect , special , incidental , or consequential damages whatsoever under any circumstance or legal theory relating in any way to the products , software , and accompanying documentation and materials , ( including , without limitation , damages for loss of business profits , business interruption , loss of business information , or any other pecuniary loss ), regardless of whether trimble has been advised of the possibility of any such loss and regardless of the course of dealing which develops or has developed between you and trimble . because some states and jurisdictions do not allow the exclusion or limitation of liability for consequential or incidental damages , the above limitation may not apply to you . notices class b statement ? notice to users. this equipment has been tested and found to comply with the limits for a class b digital device, pursuant to part 15 of the fcc rules. these limits are designed to provide reasonable protection against harmful interference in a residential installation. this equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communication. however, there is no guarantee that interference will not occur in a particular installation. if this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: ? reorient or relocate the receiving antenna. ? increase the separation between the equipment and the receiver. ? connect the equipment into an outlet on a circuit different from that to which the receiver is connected. ? consult the dealer or an experienced radio/tv technician for help. changes and modifications not expressly approved by the manufacturer or registrant of this equipment can void your authority to operate this equipment under federal communications commission rules. european community (ce) directive conformance statement the acutime 2000 gps smart antenna conforms with the essential requirements of the emc directive 89/336/eec. a declaration of conformity indicating the requirements met has been signed at trimble navigation limited, 645 north mary avenue, sunnyvale, ca 94086, usa. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide v contents about this manual scope and audience . . . . . . . . . . . . . . . . . . . . . . . . xix organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . xx reader feedback . . . . . . . . . . . . . . . . . . . . . . . . . . xxi related information . . . . . . . . . . . . . . . . . . . . . . . . xxii update notes . . . . . . . . . . . . . . . . . . . . . . .xxii world wide web (www) site . . . . . . . . . . . . . .xxii technical assistance. . . . . . . . . . . . . . . . . . . .xxii abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiii document conventions . . . . . . . . . . . . . . . . . . . . . . . xxiii cautions and notes . . . . . . . . . . . . . . . . . . . . . . . . . xxiv 1 introduction 1.1 overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.2 acutime 2000 gps smart antenna features. . . . . . . . . . . . 1-2 1.3 starter kit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 2 getting started 2.4 connecting the smart antenna . . . . . . . . . . . . . . . . . . . 2-2 2.5 connecting the computer and power source . . . . . . . . . . . 2-3 2.6 communicating with the acutime 2000 . . . . . . . . . . . . . . 2-4 www.datasheet.co.kr datasheet pdf - http://www..net/ vi acutime 2000 synchronization kit user guide contents 3 acutime 2000 installation 3.1 choosing a location . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3.2 mounting the smart antenna. . . . . . . . . . . . . . . . . . . . 3-3 3.3 routing and securing the interface cable . . . . . . . . . . . . . 3-4 3.4 connecting the host system . . . . . . . . . . . . . . . . . . . . 3-5 4 acutime 2000 connections 4.1 interface and power connections. . . . . . . . . . . . . . . . . . 4-1 4.2 interface cables and connectors . . . . . . . . . . . . . . . . . . 4-3 4.2.1 pin-outs . . . . . . . . . . . . . . . . . . . . . . . . . .4-4 4.3 connection instructions . . . . . . . . . . . . . . . . . . . . . . 4-6 4.3.1 power connection (red and black wires) . . . . . . . .4-6 4.3.2 timing pulse connections . . . . . . . . . . . . . . . . .4-6 4.3.3 serial port connections . . . . . . . . . . . . . . . . . .4-7 4.3.4 event input. . . . . . . . . . . . . . . . . . . . . . . . .4-8 5 system operation 5.1 start-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 5.2 automatic operation . . . . . . . . . . . . . . . . . . . . . . . . 5-2 5.2.1 satellite masks. . . . . . . . . . . . . . . . . . . . . . .5-2 5.2.2 tracking modes . . . . . . . . . . . . . . . . . . . . . .5-4 5.2.3 pps output options . . . . . . . . . . . . . . . . . . . .5-6 5.2.4 pps quantization error . . . . . . . . . . . . . . . . . .5-7 5.2.5 external event input . . . . . . . . . . . . . . . . . . . .5-9 5.2.6 cable delay compensation . . . . . . . . . . . . . . . .5-9 5.3 serial data communication . . . . . . . . . . . . . . . . . . . . 5-10 5.3.1 port b . . . . . . . . . . . . . . . . . . . . . . . . . . .5-10 5.3.2 port a (timing) . . . . . . . . . . . . . . . . . . . . . .5-11 5.4 gps timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12 5.4.1 timing operation . . . . . . . . . . . . . . . . . . . . .5-13 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide vii contents 5.5 using the acutime 2000 in mobile applications . . . . . . . . . 5-15 5.6 customizing acutime 2000 operations . . . . . . . . . . . . . . 5-16 a trimble standard interface protocol a.1 interface scope . . . . . . . . . . . . . . . . . . . . . . . . . . . a-1 a.1.1 packet structure . . . . . . . . . . . . . . . . . . . . . .a-2 a.2 physical interface characteristics . . . . . . . . . . . . . . . . . a-3 a.2.1 nomenclature . . . . . . . . . . . . . . . . . . . . . . .a-3 a.2.2 protocol capabilities. . . . . . . . . . . . . . . . . . . .a-4 a.2.3 event input. . . . . . . . . . . . . . . . . . . . . . . . .a-5 a.3 packets output at power-up . . . . . . . . . . . . . . . . . . . . a-5 a.4 receiver warm start . . . . . . . . . . . . . . . . . . . . . . . . a-6 a.5 default background packets (port b) . . . . . . . . . . . . . . . a-7 a.6 default automatic position and velocity reports . . . . . . . . . a-8 a.7 automatic primary and supplemental timing reports . . . . . . a-8 a.8 low-latency timing packets. . . . . . . . . . . . . . . . . . . . a-9 a.9 event packets . . . . . . . . . . . . . . . . . . . . . . . . . . . . a-10 a.10 satellite data packets. . . . . . . . . . . . . . . . . . . . . . . . a-10 a.11 customizing receiver operations . . . . . . . . . . . . . . . . . a-11 a.12 command packets sent to the receiver . . . . . . . . . . . . . . a-13 a.13 report packets sent by the gps receiver to the user . . . . . . . a-15 a.14 packet descriptions. . . . . . . . . . . . . . . . . . . . . . . . . a-18 a.15 custom oem packets . . . . . . . . . . . . . . . . . . . . . . . a-82 a.16 tsip superpackets . . . . . . . . . . . . . . . . . . . . . . . . . a-82 a.17 datums . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . a-122 a.18 sample tsip routines . . . . . . . . . . . . . . . . . . . . . . . a-130 b timing receiver monitor b.1 start-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . b-1 b.2 main screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . b-2 www.datasheet.co.kr datasheet pdf - http://www..net/ viii acutime 2000 synchronization kit user guide contents c nmea 0183 c.1 the nmea 0183 communication interface . . . . . . . . . . . . c-2 c.2 nmea 0183 message format . . . . . . . . . . . . . . . . . . . c-2 c.3 nmea 0183 message options . . . . . . . . . . . . . . . . . . . c-4 c.4 nmea 0183 message formats. . . . . . . . . . . . . . . . . . . c-5 c.4.1 gga ? gps fix data . . . . . . . . . . . . . . . . . . .c-5 c.4.2 gll ? geographic position ? latitude/longitude . . . .c-6 c.4.3 gsa ? gps dop and active satellites . . . . . . . . . .c-7 c.4.4 gsv ? gps satellites in view. . . . . . . . . . . . . . .c-8 c.4.5 rmc ? recommended minimum specific gps/ transit data . . . . . . . . . . . . . . . . . . . . . . . .c-9 c.4.6 vtg ? track made good and ground speed . . . . . . .c-10 c.4.7 zda ? time & date . . . . . . . . . . . . . . . . . . . .c-11 d specifications and drawings d.1 acutime 2000 gps smart antenna specifications. . . . . . . . . d-1 d.2 acutime 2000 standard interface cable diagram . . . . . . . . . d-5 e theory of operation e.1 gps satellite message . . . . . . . . . . . . . . . . . . . . . . . e-2 e.2 satellite acquisition and time to first fix . . . . . . . . . . . . . e-3 e.2.1 cold start . . . . . . . . . . . . . . . . . . . . . . . . .e-3 e.2.2 warm start . . . . . . . . . . . . . . . . . . . . . . . . .e-4 e.2.3 "garage search" strategy . . . . . . . . . . . . . . . . .e-5 e.2.4 hot start . . . . . . . . . . . . . . . . . . . . . . . . . .e-5 e.3 position accuracy . . . . . . . . . . . . . . . . . . . . . . . . . e-6 e.3.1 selective availability (s/a) . . . . . . . . . . . . . . . .e-6 e.4 coordinate systems. . . . . . . . . . . . . . . . . . . . . . . . . e-7 e.4.1 tsip . . . . . . . . . . . . . . . . . . . . . . . . . . . .e-7 e.4.2 nmea 0183 . . . . . . . . . . . . . . . . . . . . . . . .e-7 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide ix contents e.5 performance characteristics . . . . . . . . . . . . . . . . . . . . e-8 e.5.1 update rate . . . . . . . . . . . . . . . . . . . . . . . .e-8 e.5.2 dynamic limits . . . . . . . . . . . . . . . . . . . . . .e-8 e.5.3 re-acquisition. . . . . . . . . . . . . . . . . . . . . . .e-8 e.6 system architecture . . . . . . . . . . . . . . . . . . . . . . . . e-10 glossary www.datasheet.co.kr datasheet pdf - http://www..net/ x acutime 2000 synchronization kit user guide contents www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide xi list of figures figure 1-1 acutime 2000 gps smart antenna enclosure . . . . . . . 1-3 figure 2-1 connection diagram . . . . . . . . . . . . . . . . . 2-3 figure 3-1 mounted antenna . . . . . . . . . . . . . . . . . . 3-2 figure 4-1 acutime 2000 interface connector . . . . . . . . . . . 4-2 figure 4-2 acutime 2000 12-pin connector format. . . . . . . . . . 4-2 figure 5-1 pps quantization error . . . . . . . . . . . . . . . . 5-7 figure 5-2 removing the quantization error from the pps output . . . 5-8 figure d-1 acutime 2000 standard interface cable. . . . . . . . . . d-6 figure e-1 acutime 2000 block diagram (rs-232 version) . . . . . . e-11 figure e-2 acutime 2000 block diagram (rs-422 version) . . . . . . e-11 www.datasheet.co.kr datasheet pdf - http://www..net/ xii acutime 2000 synchronization kit user guide list of figures www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide xiii list of tables table 4-1 mating connectors . . . . . . . . . . . . . . . . . . . . . . . 4-3 table 4-2 acutime 2000 rs-422 cable pin-out . . . . . . . . . . . . . 4-4 table 4-3 acutime 2000 rs-232 cable pin-out . . . . . . . . . . . . . 4-5 table 5-1 default satellite mask settings. . . . . . . . . . . . . . . . . 5-2 table 5-3 oem configuration (segment 3) . . . . . . . . . . . . . . . . 5-17 table 5-2 receiver configuration (segment 2) . . . . . . . . . . . . . . 5-17 table 5-5 pps configuration (segment 5). . . . . . . . . . . . . . . . . 5-18 table 5-6 position information (segment 6) . . . . . . . . . . . . . . . 5-18 table 5-4 port a and b configuration (segment 4) . . . . . . . . . . . . 5-18 table 5-7 self-survey configuration (segment 7) . . . . . . . . . . . . 5-19 table 5-8 nmea configuration (segment 8) . . . . . . . . . . . . . . . 5-19 table 5-9 utc information (segment 11) . . . . . . . . . . . . . . . . 5-19 table a-1 acutime 2000 port translation table . . . . . . . . . . . . . a-3 table a-2 secondary port features . . . . . . . . . . . . . . . . . . . . a-4 table a-3 event packets . . . . . . . . . . . . . . . . . . . . . . . . . . a-5 table a-4 packets output at power-up . . . . . . . . . . . . . . . . . . a-5 table a-5 receiver warm start commands . . . . . . . . . . . . . . . a-6 table a-6 background packets . . . . . . . . . . . . . . . . . . . . . . a-7 table a-7 automatic position and velocity reports . . . . . . . . . . . a-8 table a-8 low-latency timing packets . . . . . . . . . . . . . . . . . a-9 table a-9 satellite data packets. . . . . . . . . . . . . . . . . . . . . . a-10 table a-10 customizing receiver operations . . . . . . . . . . . . . . . a-11 table a-11 advanced packets . . . . . . . . . . . . . . . . . . . . . . . a-12 www.datasheet.co.kr datasheet pdf - http://www..net/ xiv acutime 2000 synchronization kit user guide list of tables table a-12 command packets sent to the receiver . . . . . . . . . . . . a-13 table a-13 report packets sent by gps receiver to user . . . . . . . . . a-15 table a-14 command packet 1d - clear oscillator offset. . . . . . . . . a-18 table a-15 command packet 1d - set oscillator offset . . . . . . . . . . a-18 table a-16 command packet 1e . . . . . . . . . . . . . . . . . . . . . . a-19 table a-17 command packet 23 . . . . . . . . . . . . . . . . . . . . . . a-21 table a-18 command packet 2b . . . . . . . . . . . . . . . . . . . . . . a-24 table a-19 command packet 2e . . . . . . . . . . . . . . . . . . . . . . a-25 table a-20 command packet 35 . . . . . . . . . . . . . . . . . . . . . . a-28 table a-21 command packet 38 . . . . . . . . . . . . . . . . . . . . . . a-33 table a-22 command packet 39 . . . . . . . . . . . . . . . . . . . . . . a-34 table a-23 command packet 3a . . . . . . . . . . . . . . . . . . . . . . a-35 table a-24 command packet 3b . . . . . . . . . . . . . . . . . . . . . . a-35 table a-25 command packet 3c . . . . . . . . . . . . . . . . . . . . . . a-36 table a-26 command packet 3f-11 . . . . . . . . . . . . . . . . . . . . a-37 table a-27 report packet 40 . . . . . . . . . . . . . . . . . . . . . . . . a-37 table a-28 report packet 41 . . . . . . . . . . . . . . . . . . . . . . . . a-38 table a-29 relationship between packet 41 and packet 46 . . . . . . . . a-39 table a-30 report packet 42 . . . . . . . . . . . . . . . . . . . . . . . . a-40 table a-31 report packet 43 . . . . . . . . . . . . . . . . . . . . . . . . a-41 table a-32 report packet 45 . . . . . . . . . . . . . . . . . . . . . . . . a-42 table a-33 report packet 46 . . . . . . . . . . . . . . . . . . . . . . . . a-43 table a-34 report packet 46 . . . . . . . . . . . . . . . . . . . . . . . . a-44 table a-35 report packet 47 . . . . . . . . . . . . . . . . . . . . . . . . a-45 table a-36 report packet 49 . . . . . . . . . . . . . . . . . . . . . . . . a-46 table a-37 report packet 4a ? report reference altitude . . . . . . . . a-46 table a-38 report packet 4a ? report single-precision lla position . . a-47 table a-39 report packet 4b . . . . . . . . . . . . . . . . . . . . . . . . a-48 table a-40 byte 1 bit encoding ? status 1 . . . . . . . . . . . . . . . . . a-48 table a-41 report packet 4c . . . . . . . . . . . . . . . . . . . . . . . . a-49 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide xv list of tables table a-42 report packet 4e . . . . . . . . . . . . . . . . . . . . . . . . a-50 table a-43 report utc parameters . . . . . . . . . . . . . . . . . . . . a-51 table a-44 report packet 54 . . . . . . . . . . . . . . . . . . . . . . . . a-52 table a-45 0x56 ? velocity fix, east-north-up (enu) report . . . . . . a-53 table a-46 report packet 57 . . . . . . . . . . . . . . . . . . . . . . . . a-54 table a-47 report packet 58 . . . . . . . . . . . . . . . . . . . . . . . . a-55 table a-48 report packet 58 ? almanac data report . . . . . . . . . a-56 table a-50 report packet 58 ? ionosphere data report. . . . . . . . a-57 table a-49 report packet 58 ? almanac health data report . . . . a-57 table a-52 report packet 58 ? ephemeris data report . . . . . . . . a-58 table a-51 report packet 58 ? utc data report . . . . . . . . . . . . . a-58 table a-53 report packet 59 . . . . . . . . . . . . . . . . . . . . . . . . a-60 table a-54 report packet 5a . . . . . . . . . . . . . . . . . . . . . . . . a-61 table a-55 report packet 5b . . . . . . . . . . . . . . . . . . . . . . . . a-64 table a-56 report packet 5c . . . . . . . . . . . . . . . . . . . . . . . . a-65 table a-57 report packet 5f-11 ? eeprom segment status report . . . a-67 table a-58 report packet 0x60 data formats . . . . . . . . . . . . . . . a-68 table a-59 report packet 0x60 data formats for health and power . . . a-69 table a-60 command packet 0x61 data formats . . . . . . . . . . . . . a-70 table a-61 report packet 6d . . . . . . . . . . . . . . . . . . . . . . . . a-71 table a-62 command packet 7a . . . . . . . . . . . . . . . . . . . . . . a-72 table a-63 report packet 83 . . . . . . . . . . . . . . . . . . . . . . . . a-73 table a-64 report packet 84 . . . . . . . . . . . . . . . . . . . . . . . . a-74 table a-65 survey state configurations . . . . . . . . . . . . . . . . . . a-75 table a-66 vaild gps configuration settings . . . . . . . . . . . . . . . a-76 table a-67 command packet bb. . . . . . . . . . . . . . . . . . . . . . a-78 table a-68 command packet bc. . . . . . . . . . . . . . . . . . . . . . a-80 table a-69 command packet 8e-14 . . . . . . . . . . . . . . . . . . . . a-84 table a-70 command packet 8e-14 . . . . . . . . . . . . . . . . . . . . a-85 table a-71 command packet 8e-20 . . . . . . . . . . . . . . . . . . . . a-86 www.datasheet.co.kr datasheet pdf - http://www..net/ xvi acutime 2000 synchronization kit user guide list of tables table a-72 command packet 0x8e-45 . . . . . . . . . . . . . . . . . . . a-87 table a-73 command packet 8e-4a . . . . . . . . . . . . . . . . . . . . a-88 table a-74 command packet 8e-4d . . . . . . . . . . . . . . . . . . . . a-89 table a-75 command packet 8e-4d - packets affected by bits . . . . . a-90 table a-76 command packet 0x8e-4e . . . . . . . . . . . . . . . . . . . a-92 table a-77 command packet 0x8e-4f . . . . . . . . . . . . . . . . . . . a-92 table a-78 command packet 8e-a5 . . . . . . . . . . . . . . . . . . . . a-94 table a-79 command packet 8e-a6 . . . . . . . . . . . . . . . . . . . . a-95 table a-80 command packet 8e-a9 data format < acutime 2000 synchronization kit user guide xvii list of tables table c-3 gga ? gps fix data message parameters . . . . . . . . . . c-5 table c-4 gll ? geographic position ? latitude / longitude message parameters . . . . . . . . . . . . . . . . . . . . . . c-6 table c-5 gsa ? gps dop and active satellites message parameters . c-7 table c-6 gsv ? gps satellites in view message parameters . . . . . . c-8 table c-7 rmc ? recommended minimum specific gps / transit data message parameters . . . . . . . . . . . . . . . c-9 table c-8 vtg ? track made good and ground speed message parameters . . . . . . . . . . . . . . c-10 table c-9 zda ? time & date message parameters . . . . . . . . . . . c-11 table d-1 physical specifications . . . . . . . . . . . . . . . . . . . . . d-1 table d-3 performance specifications . . . . . . . . . . . . . . . . . . d-2 table d-2 environmental specifications . . . . . . . . . . . . . . . . . d-2 table d-4 electrical specifications . . . . . . . . . . . . . . . . . . . . d-3 table d-5 serial protocols . . . . . . . . . . . . . . . . . . . . . . . . . d-4 table e-1 dynamic upper bound . . . . . . . . . . . . . . . . . . . . . e-8 www.datasheet.co.kr datasheet pdf - http://www..net/ xviii acutime 2000 synchronization kit user guide list of tables www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide xix about this manual welcome to the acutime 2000 synchronization kit user guide . this manual describes how to integrate the acutime 2000 smart antenna with your host system. scope and audience even if you have used other global positioning system (gps) products before, trimble recommends that you spend some time reading this manual to learn about the special features of this product. if you are not familiar with gps, trimble recommends that you do one of the following: ? read the booklet gps, a guide to the next utility (available from trimble). complete the gps tutorial at: www.trimble.com/gps the following sections provide you with a guide to this manual, as well as to other documentation that you may have received with this product. www.datasheet.co.kr datasheet pdf - http://www..net/ xx acutime 2000 synchronization kit user guide about this manual organization this manual contains the following: ? chapter 1, introduction, describes the acutime 2000 gps smart antenna. chapter 2, getting started, describes how to quickly install, connect and operate the acutime 2000. chapter 3, acutime 2000 installation, provides general installation guidelines. chapter 4, acutime 2000 connections, provides detailed interfacing guidelines for connecting the acutime 2000 gps smart antenna to the host system. chapter 5, system operation, describes the operating characteristics of the acutime 2000 from power-up through the output of gps information. gps timing applications are also described. appendix a, trimble standard interface protocol, defines the tsip protocol and the structure of all message packets. appendix b, timing receiver monitor, describes the monitor program included on the acutime 2000 cd-rom. appendix c, nmea 0183, provides a brief description of the nmea 0183 protocol and defines the structure of the nmea message output by the acutime 2000. appendix d, specifications and drawings, includes the specifications and mechanical drawings for the acutime 2000 gps smart antenna interface cables. appendix e, theory of operation, gives a more detailed technical description of many of the acutime 2000 gps smart antenna's operating characteristics. a brief overview of the system architecture is also presented. the glossary contains definitions of gps and technical terms used in this manual. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide xxi about this manual reader feedback your feedback about the product documentation helps us to improve it with each revision. to forward your comments, do one of the following: send an email to readerfeedback@trimble.com. complete the reader comment form at the back of this manual and mail or fax it according to the instructions at the bottom of the form. if the reader comment form is not available, send your comments and suggestions to the address in the front of this manual. please mark it attention: documentation group . all comments and suggestions become the property of trimble navigation limited. thank you for your help. www.datasheet.co.kr datasheet pdf - http://www..net/ xxii acutime 2000 synchronization kit user guide about this manual related information the following sections discuss other sources of information that introduce, extend, or update this manual. update notes if any changes are made to the firmware, update notes and firmware are posted to the trimble web site. world wide web (www) site for more information about trimble, visit our site on the world wide web: www.trimble.com technical assistance if you have a problem and cannot find the information you need in the product documentation, contact your sales representative . alternatively, request technical support via email at trimble_support@trimble.com or by phone at 1-800-767-4822. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide xxiii about this manual abbreviations in this manual, the following abbreviations are used: tsip - trimble standard interface protocol host system or host - the device or instrument connected to the acutime 2000 smart antenna the host system can be a pc, network equipment, or timing system, depending on the application. document conventions italics identify software menus, menu commands, dialog boxes, and the dialog box fields. small capitals identify user commands, directories, filenames, and filename extensions. helvetica represents messages printed on the screen. courier bold represents information that you must type in a software screen or window. helvetica bold identifies a software command button. [ctrl] is an example of a hardware function key that you must press on a personal computer (pc). if you must press more than one of these at the same time, this is represented by a plus sign, for example, [ctrl] + [c] . www.datasheet.co.kr datasheet pdf - http://www..net/ xxiv acutime 2000 synchronization kit user guide about this manual cautions and notes cautions, notes, and tips draw attention to important information and indicate its nature and purpose. i caution ? cautions describe operating procedures and practices required for correct operation and alert you to situations that could cause hardware damage or malfunction or software error. * note ? notes give additional significant information about the subject to increase your knowledge, or guide your actions. m warning ? warnings alert you to situations that could cause personal injury or unrecoverable data loss. a warning precedes the text it references. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 1-1 1 introduction this chapter provides an overview of the acutime 2000 gps smart antenna. 1.1 overview the acutime 2000 is the latest in the trimble family of gps smart antennas. the smart antenna allows oems and systems integrators to add gps capability to their product lines quickly and easily, without becoming gps experts. the trimble acutime 2000 gps smart antenna encompasses the experience of four product lines: acutis?, acutime?, acutime? ii and palisade?. the acutime 2000, using trimble?s latest gps technology, is designed for wireless voice and data network synchronization. it offers precise pps output, event input, and also supports long cable runs. the acutime 2000 is composed of a set of matched subsystems. this ensures optimal gps performance, long-term reliability, ease of operation, and easy integration. the acutime 2000 houses the gps receiver, antenna, power supply, interface and other support circuitry in a single enclosure that mounts like an antenna. as a sealed, shielded, self-contained unit with a digital interface, the acutime 2000 eliminates most of the difficulties associated with integrating gps. once power is applied, the acutime 2000 self-initializes, acquires satellite signals, and computes position and time, automatically outputting this data to the host system. www.datasheet.co.kr datasheet pdf - http://www..net/ 1-2 acutime 2000 synchronization kit user guide introduction 1 to integrate the acutime 2000, the oem only needs to add a standard serial interface port on the host system and develop a software interface. commonly used interface protocols, such as nmea 0183, and the software interface tool (the timing receiver monitor), simplify this task, minimizing the engineering costs associated with integrating the acutime 2000. 1.2 acutime 2000 gps smart antenna features the acutime 2000 has many features common to previous products in the trimble family of smart antennas, including: an 8 to 36-volt dc power supply with protection against reverse polarity. trimble's advanced multi-channel gps receiver architecture, including: the reference oscillator the synthesizer and if circuits the digital signal processing hardware a microprocessor the serial interface circuitry a patch gps antenna with a proprietary pre-amp design for excellent performance against jamming signals. a sealed, waterproof connector supporting both the power and interface connections. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 1-3 1 introduction a waterproof, uv-resistant, plastic (polycarbonate) enclosure with a proven epoxy seal. (the enclosure is illustrated in figure 1-1). figure 1-1 acutime 2000 gps smart antenna enclosure acutime 2000 generates a pps synchronized to utc within 50 nanoseconds (one sigma). this level of precision is obtained using an overdetermined time solution, an 80-nanosecond pulse steering resolution and a t-raim (time-receiver autonomous integrity monitor) algorithm. the acutime 2000?s pps conforms to rs-422, which supports long cable runs. the acutime 2000 outputs a comprehensive time packet after each pps on a dedicated serial port. it also features an automatic operating mode that requires no user or host intervention. the acutime 2000 accepts an event input and reports time stamps in response to an external event signal. the acutime 2000 is available in the following configurations: acutime 2000 with rs-422 interface and 8-channel receiver acutime 2000 with rs-232 interface and 8-channel receiver www.datasheet.co.kr datasheet pdf - http://www..net/ 1-4 acutime 2000 synchronization kit user guide introduction 1 1.3 starter kit the acutime 2000 synchronization kit includes the following: acutime 2000 with rs-422 interface and 8-channel receiver acutime 2000 user guide 100? interface cable with db25 connectors rs-422 to rs-232 converter timing receiver monitor software power supply for information about acutime 2000 interface cables, see chapter 4, acutime 2000 connections. for information about part numbers, refer to: www.trimble.com/products/ACUTIME2000 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 2-1 2 getting started this chapter describes how to quickly install, connect and communicate with the acutime 2000 gps smart antenna. * note ? for permanent installations, see the instructions in chapter 3. you will need the following items: a pc running windows the timing receiver monitor software for windows (also available on the web site) an interface cable for the smart antenna an rs-422 to rs-232 converter (included in the acutime 2000 starter kit) you may require this if you are using an acutime 2000 with an rs-422 interface. in many cases, however, a pc?s communication port is flexible enough to accept an rs-422 signal without a converter. connectors/adapters for connecting the interface cable to the pc?s communication port the interface cable included in the acutime 2000 starter kit is terminated with a db25 connector. the standard interface cables are not terminated with connectors. a dc power source the acutime 2000 accepts 8-36 v dc power, and draws approximately 110 milliamps at 12 volts. www.datasheet.co.kr datasheet pdf - http://www..net/ 2-2 acutime 2000 synchronization kit user guide getting started 2 a mounting pole the acutime 2000 accepts a standard 1"-14 straight thread. 2.4 connecting the smart antenna the acutime 2000 can be placed anywhere with a clear view of the sky. connect the interface cable to the smart antenna. the connector on the interface connector has a locking ring for securing the connection. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 2-3 2 getting started 2.5 connecting the computer and power source the connection instructions illustrated in figure 2-1 assume use of the trimble interface cable included in the synchronization kit. if you are using your own cable, modify the instructions accordingly. figure 2-1 connection diagram synchronization interface module wall power acutime 2000 pps port a port b port a pc port b (primary port) (rs-422 to rs-232 converter) (the starter kit includes only one cable.) www.datasheet.co.kr datasheet pdf - http://www..net/ 2-4 acutime 2000 synchronization kit user guide getting started 2 2.6 communicating with the acutime 2000 when power is applied, the acutime 2000 acquires a valid set of satellites and automatically transmits position and time messages. during the satellite acquisition process, the acutime 2000 outputs periodic status messages. to begin communicating with the acutime 2000, start the timing receiver monitor program. data fields in the timing receiver monitor program fill up as the data becomes available. for more information, see appendix b, timing receiver monitor. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 3-1 3 acutime 2000 installation this chapter provides installation guidelines for the acutime 2000 gps smart antenna. installation of the acutime 2000 requires four steps: 1. choosing a location. 2. mounting the smart antenna. 3. routing and securing the interface cable. 4. connecting the host system. each of these installation steps is described on the following pages. 3.1 choosing a location select an outdoor location for the antenna (such as the roof of your building) that has a relatively unobstructed view of the sky. consider the length of the cable run and the length of the interface cable when selecting a location. the acutime 2000 gps smart antenna is designed for a pole mount. (the mounting pole is not included with the acutime 2000.) pole mounting is illustrated in figure 3-1. www.datasheet.co.kr datasheet pdf - http://www..net/ 3-2 acutime 2000 synchronization kit user guide acutime 2000 installation 3 figure 3-1 mounted antenna the antenna can receive satellite signals through glass, canvas, and thin fiberglass, but dense wood, concrete and metal structures shield the antenna from satellite signals. the acutime 2000 gps smart antenna contains an active antenna. for optimal performance, place it as far as possible from transmitting antennas, including radars, satellite communication equipment and cellular transmitters. when locating the antenna near a radar www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 3-3 3 acutime 2000 installation installation, ensure that the antenna is positioned outside of the radar?s cone of transmission. when installing the antenna near satellite communication equipment, follow the same guideline. for best results, mount the antenna below and at least ten feet away from satellite communication equipment. for installations exposed to shock or vibration exceeding the limits specified in appendix d, specifications and drawings, use a mounting scheme that isolates the acutime 2000 from the excessive shock or vibration. 3.2 mounting the smart antenna the smart antenna is designed for a pole mount, as illustrated in figure 3-1. the threaded socket in the base of the antenna accepts a standard 1"-14 straight thread. a wide variety of 1"-14 pole mounts are available from marine hardware suppliers. after obtaining an appropriate mounting pole, follow these simple steps to install the acutime 2000 gps smart antenna. 1. secure the mounting pole to a solid structure so that it is oriented vertically. 2. thread the smart antenna onto the pole or pipe and hand- tighten until snug. i caution ? do not over-tighten the smart antenna on the pole or use a tool?this could damage the threaded socket in the base of the antenna. also, do not use a thread-locking compound because it can damage the plastic housing. 3. connect the interface cable to the smart antenna. the connector on the interface connector has a locking ring for securing the connection. www.datasheet.co.kr datasheet pdf - http://www..net/ 3-4 acutime 2000 synchronization kit user guide acutime 2000 installation 3 i caution ? do not over-tighten the locking ring?this can strip the connector. 3.3 routing and securing the interface cable after the smart antenna is mounted: 1. route the interface cable from the smart antenna to the host location. * note ? the interface cable is a digital cable, so it can be spliced and extended, if necessary. choose the most direct path to the host system, while avoiding the following hazards: sharp bends or kinks in the cable hot surfaces (exhaust manifolds or stacks) rotating or reciprocating equipment sharp or abrasive surfaces door and window jambs corrosive fluids or gases 2. when you have established the ideal cable routing, secure the cable along the routing using tie-wraps. when securing the cable, start at the antenna and work towards the host system. to provide strain relief for the interface cable connections, ensure that the cable is secured at points close to the smart antenna and the host system. * note ? additional protection (for example, heat-shrink tubing) may be required to protect the cable jacket at points where the cable enters or exits bulkheads, especially if the opening is rough or sharp. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 3-5 3 acutime 2000 installation 3. once the cable is secured, the host end of the cable can be cut to an appropriate length (if necessary). leave enough slack to allow for easy connection to the host and normal movement (for example, rack, gimbal or swivel mounts). 3.4 connecting the host system the final step, if applicable, is the installation of the connector on the host end of the cable. the connector installation instructions depend on the type of connector required by the host system. for information on pin-outs, see chapter 4, acutime 2000 connections. www.datasheet.co.kr datasheet pdf - http://www..net/ 3-6 acutime 2000 synchronization kit user guide acutime 2000 installation 3 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 4-1 4 acutime 2000 connections this chapter provides instructions on connecting the acutime 2000 to the host system and power source. 4.1 interface and power connections the black plastic connector located in the base of the acutime 2000 supports both the interface and power connections. the acutime 2000 uses a 12-pin connector. figure 4-1 illustrates the location of the connector. www.datasheet.co.kr datasheet pdf - http://www..net/ 4-2 acutime 2000 synchronization kit user guide acutime 2000 connections 4 figure 4-1 acutime 2000 interface connector figure 4-2 illustrates the pin arrangement for this connector. figure 4-2 acutime 2000 12-pin connector format 2 3 4 5 6 7 8 9 1 10 11 12 2 3 4 5 6 7 8 9 1 10 11 12 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 4-3 4 acutime 2000 connections 4.2 interface cables and connectors interface cables for the acutime 2000 are available in the following standard lengths. ? 50' (15-meter) 100' (30-meter) 200' (60-meter) 400' (120-meter) contact trimble for custom-length cables up to 300 m. for a list of part numbers, refer to: www.trimble.com/products/ACUTIME2000 note ? the standard interface cables offered by trimble are not terminated on the host end, so the appropriate connector must be installed before connecting the cable to the host system. for oems and integrators who want to produce their own interface cables, table 4-3 specifies the source and part number of the mating cable connectors for the 12-pin connector. table 4-1 mating connectors antenna connector mating connector manufacturer description mmp series #68001-2212p1 mmp series #26c-2212s1 deutsch commercial products 5733 w. whittier avenue hemet, california 92545 phone: (909) 765-2200 fax: (909) 922-1544 connector body (requires a molded backshell) www.datasheet.co.kr datasheet pdf - http://www..net/ 4-4 acutime 2000 synchronization kit user guide acutime 2000 connections 4 4.2.1 pin-outs table 4-2 lists the pin-out descriptions and color codes for the standard interface cables. table 4-2 acutime 2000 rs-422 cable pin-out signal description wire color protocol acutime 2000 connector dc power (+8 to +36 volts dc) red +8 to 36 v pin 1 port b: rs-422 / receive violet tsip rs422 pin 2 port b: rs-422 / receive + orange tsip rs422 pin 3 port b: rs-422 / transmit - brown tsip rs422 pin 4 port b: rs-422 / transmit + yellow tsip rs422 pin 5 port a: rs-422 / receive - white event input / rtcm rs422 pin 6 port a: rs-422 / receive + gray event input/ rtcm rs422 pin 7 port a: rs-422 / transmit - green nmea / tsip rs422 pin 8 dc ground black ground pin 9 port a: rs-422 / transmit + blue nmea / tsip rs422 pin 10 one pps: transmit + orange w/ white stripe rs422 pin 11 one pps: transmit - black w/ white stripe rs422 pin 12 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 4-5 4 acutime 2000 connections * note ? the cable color codes listed in this table apply only if you are using the trimble interface cable. * note ? receive and transmit are with respect to the acutime 2000 gps smart antenna. the host transmit should be connected to the acutime 2000?s receive, and vice versa. * note ? the acutime 2000 with an rs-232 interface is designed especially for short cable runs (usually under 50 feet). for longer cable runs, an rs-422 interface is recommended. table 4-3 acutime 2000 rs-232 cable pin-out signal description wire color protocol acutime 2000 connector dc power red +8 to +36v pin 1 port b: rs-232 receive violet tsip rs232 pin 2 not used orange not used pin 3 port b: rs-232 transmit brown tsip rs232 pin 4 not used yellow not used pin 5 port a: rs-232 receive white event input/rtcm pin 6 port a: rs-232 transmit gray tsip rs232 pin 7 vback green battery backup pin 8 dc ground black ground pin 9 not used blue not used pin 10 one pps: transmit + orange/white rs422 pin 11 one pps: transmit - black/white rs422 pin 12 www.datasheet.co.kr datasheet pdf - http://www..net/ 4-6 acutime 2000 synchronization kit user guide acutime 2000 connections 4 4.3 connection instructions this section provides detailed information for connecting the acutime 2000's power, timing pulse and data packet lines. 4.3.1 power connection (red and black wires) the red wire (acutime 2000 pin #1) and black wire (acutime 2000 pin #9) in the interface cable support the power and ground connections, respectively. the acutime 2000 features a switching dc power supply, which accepts from 8 to 36 volts. the acutime 2000 is protected against reverse polarity and brief over-voltage conditions; however, sustained over-voltage conditions can cause permanent damage. m warning ? voltages exceeding 36 volts can cause permanent damage to the acutime 2000's power supply. the typical power consumption of the acutime 2000 at an input voltage of 12 volts is 110 milliamps, or 1.3 watts. * note ? the acutime 2000 requires a minimum of 8 volts at the interface connector. when specifying the supply voltage, line losses in the interface cable must be considered. to account for line loss, the supply voltage may need to exceed 8 volts to satisfy the minimum voltage at the acutime 2000. 4.3.2 timing pulse connections the acutime 2000 outputs a timing pulse for use in timing and synchronization applications. the timing pulse is generated using an rs-422 line driver circuit (pins #11 and #12). the leading edge of the pps output pulse is synchronized to utc. the width of the pulse's leading edge is 20 nanoseconds or less. the exact width and shape of the pulse depends on the distributed capacitance in the interface cable. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 4-7 4 acutime 2000 connections for more information on using the timing pulse, see chapter 5, system operation. 4.3.3 serial port connections the recommended use of the serial ports on the acutime 2000 for most users is as follows: use port b to configure the acutime 2000 as necessary. disable the automatic output packets on port b using command packet 8e-a5. use port b to transmit the desired timing packet. use port b to query for specific satellite data as needed. use the port a receive line to time-tag external events or input rtcm data. if you have two serial ports, use ports a and b on the acutime 2000 as follows: use port b to configure the acutime 2000 as necessary. use port a to transmit the desired timing packet. use port b to query for specific satellite data as needed. use the port a receive line to time-tag external events or input rtcm data. port b port b is the primary serial port for the acutime 2000. you can send commands, receive command replies, and query for and receive a variety of satellite data (for example, ephemeris, tracking information, signal levels, and so on) using port b. you can also receive timing packets that are synchronized with the pps output on port b. www.datasheet.co.kr datasheet pdf - http://www..net/ 4-8 acutime 2000 synchronization kit user guide acutime 2000 connections 4 tsip timing packets 8f-0b, 8f-ab and 8f-ac (which work together as a pair of packets) or 8f-ad can be enabled on port b using command packet 8e-a5. these packets are sent within 30 milliseconds after the pps pulse when enabled. by default, the acutime 2000 automatically sends a variety of satellite data packets on port b that you may not need. you can disable these automatic output packets with command packet 8e-a5 so that only the timing packets are sent. you can also choose to receive these timing packets on port a, which serves as a dedicated transmit port for timing packets, and use port b to send commands and receive satellite data. port b can also be configured to transmit nmea packets, but these packets are not guaranteed to be sent within 30 milliseconds after the pps output. port a by default, the port a receive line is used to receive external event inputs as described below; however, port a can also receive serial rtcm (differential corrections.) when you enable rtcm messages on port a (by sending command packets on port b), the event input mechanism is automatically disabled. when rtcm messages are off (the default state), the event input mechanism is automatically enabled. 4.3.4 event input the acutime 2000 accepts an external event input in the form of an rs-422 pulse. the external event pulse input is supported on port a (pins #6 and #7). the acutime 2000 transmits a tsip time packet (8fx0b or 8fxad) in response to the event input. the tsip packet increments the event count field for each event received. the event time stamp is generated within 320 nanoseconds of arrival at the acutime 2000?s interface connector. the precision of the time stamp is subject to selective availability. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 4-9 4 acutime 2000 connections * note ? these port a pins are shared between the external event input and serial rtcm message inputs. when differential gps is enabled, this input is set up to receive rtcm messages. when differential gps is off, this input is set up to receive external event signals. www.datasheet.co.kr datasheet pdf - http://www..net/ 4-10 acutime 2000 synchronization kit user guide acutime 2000 connections 4 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 5-1 5 system operation this chapter describes the operating characteristics of the acutime 2000 gps smart antenna, including start-up, satellite acquisition, operating modes, serial data communication, and the timing pulse. the acutime 2000 acquires satellites and computes position and time solutions. it outputs data in the tsip (or nmea) protocol through its serial ports. for more technical information on system operation, see appendix f, theory of operation . 5.1 start-up at power-up, the acutime 2000 automatically begins to acquire and track gps satellite signals. it typically obtains its first fix in under two minutes. during the satellite acquisition process, the acutime 2000 outputs periodic tsip status messages on port b. these status messages confirm that the receiver is working. * note ? the acutime 2000 has no provision for external backup power and always begins operation from a cold start unless a warm start is forced by uploading almanac data and time. www.datasheet.co.kr datasheet pdf - http://www..net/ 5-2 acutime 2000 synchronization kit user guide system operation 5 5.2 automatic operation when the acutime 2000 has acquired and locked onto a set of satellites that pass the mask criteria listed below, and has obtained a valid ephemeris for each satellite, it performs a self-survey. after a number of position fixes, lasting approximately 40 minutes, the self- survey is complete. at that time, the acutime 2000 automatically switches to a time-only mode and periodic outputs of navigation information cease. 5.2.1 satellite masks the acutime 2000 continuously tracks and uses up to eight satellites in an overdetermined clock solution. the satellites must pass the mask criteria to be included in the solution. table 5-1 lists the default satellite masks used by the acutime 2000. these masks serve as the screening criteria for satellites used in fix computations and ensure that solutions meet a minimum level of accuracy. the satellite masks can be adjusted using the tsip protocol described in appendix a, trimble standard interface protocol. elevation mask satellites below 10 elevation are not used in the solution. generally, signals from low-elevation satellites are of poorer quality than signals from higher elevation satellites. these signals travel farther through the ionospheric and tropospheric layers and undergo distortion due to these atmospheric conditions. table 5-1 default satellite mask settings mask setting notes elevation 10 sv elevation above horizon snr 4 signal strength dop 8 self-survey only www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 5-3 5 system operation snr mask although the acutime 2000 is capable of tracking signals with snrs as low as 2, the default snr mask is set to 4 to eliminate poor quality signals from the fix computation. low snr values can result from: low-elevation satellites partially obscured signals (for example, dense foliage) multi-reflected signals (multipath) multi-reflected signals, also known as multipath, can degrade the position solution. multipath is most commonly found in urban environments with many tall buildings and a preponderance of mirrored glass. multi-reflected signals tend to be weak (low snr value), since each reflection diminishes the signal. setting the snr mask to 4 or higher minimizes the impact of multi-reflected signals. pdop mask position dilution of position (pdop) is a measure of the error caused by the geometric relationship of the satellites used in the position solution. satellite sets that are tightly clustered or aligned in the sky have a high pdop and contribute to a lower position accuracy. for most applications, a pdop mask of 8 offers a satisfactory trade-off between accuracy and gps coverage. with worldwide gps coverage, the pdop mask can be lowered even more for many applications without sacrificing coverage. * note ? pdop is only applicable during self-survey or whenever the receiver is performing position fixes. www.datasheet.co.kr datasheet pdf - http://www..net/ 5-4 acutime 2000 synchronization kit user guide system operation 5 5.2.2 tracking modes the acutime 2000 operates in one of two main fix modes: self-survey (position fix mode) overdetermined clock mode after establishing a reference position in self-survey mode, the acutime 2000 automatically switches to overdetermined (od) clock mode. self-survey mode at power-on, the acutime 2000 performs a self-survey by averaging 2000 position fixes. the number of position fixes until survey completion is configurable using the 8e-4b or 8e-a9 command. the default mode during self-survey is 3-d manual, where the receiver must obtain a 3-d solution with a pdop below both the pdop mask and pdop switch. the pdop mask and switch criteria can be set and queried using a tsip packet. if fewer than four conforming satellites are visible, the acutime 2000 suspends data output. the highest accuracy fix mode is 3-d manual, where altitude is always calculated along with the latitude, longitude, and time. obtaining a position requires four satellites with a pdop below the pdop mask. depending on how the pdop mask is set, 3-d mode can be restrictive when the receiver is subjected to frequent obscuration or when the geometry is poor due to an incomplete constellation. if only a 2-d solution is desired, or if the exact altitude is known, 2-d manual should be requested. in this case, the receiver uses either the last altitude obtained in a 3-d fix, or the altitude supplied by the user. any error in the assumed altitude affects the accuracy of the latitude and longitude solution. use packet bb to set the desired position fix mode. * note ? altitude and the fix mode are stored in non-volatile memory. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 5-5 5 system operation overdetermined clock mode overdetermined clock mode is used only in stationary timing applications. this is acutime 2000's default mode. after the acutime 2000 self-surveys its static reference position, it automatically switches to overdetermined clock mode and determines the clock solution. the timing solution is qualified by a t-raim algorithm, which automatically detects and rejects faulty satellites from the solution. in this mode, the acutime 2000 does not navigate or update positions and velocities, but maintains the pps output, solving only for the receiver clock error (bias) and error rate (bias rate). www.datasheet.co.kr datasheet pdf - http://www..net/ 5-6 acutime 2000 synchronization kit user guide system operation 5 5.2.3 pps output options the pps (pulse per second) output is the primary timing output generated by the acutime 2000. in all configurations of the product, the pps output is provided through a rs-422 differential driver. although using a rs-422 differential receiver to receive the pps provides the best noise immunity, you can use just one side of the differential signal for single-ended applications. you can program the characteristics of the pps output using tsip packets. packet 0x8e-4a allows you to enable or disable (turn it on or off), control the polarity, select the time base (gps or utc) and set the offset (control the cable delay compensation) of the pps output. packet 0x8e-4e allows you to set an accuracy criterion for the generation of the pps signal based on the number of usable satellites. the accuracy of the pps output depends to some degree on the number of satellites used in the solution that determine the placement of the pps output. in some systems, it is preferable to have the pps generated only when it meets the highest levels of accuracy and to leave it off if these accuracy levels are not met. packet 0x8e-4f allows you to select the width of the pps output from 10 us to 500 ms. * note ? for a complete description of the packets described here, see appendix a, trimble standard interface protocol. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 5-7 5 system operation 5.2.4 pps quantization error the acutime 2000 uses a high-precision, fixed-frequency oscillator as the timing source to down-convert and decode the gps signal and to generate the pps output signal. since a fixed-frequency oscillator is used, the acutime 2000 must place the pps output on the clock edge that it determines is closest to utc or gps. this situation results in a quantization error on the placement of the pps whose magnitude is equal to one-half the period of the fixed frequency oscillator. the oscillator frequency is 12.504 mhz, which is equivalent to a period just under 80 nanoseconds; therefore, the quantization error on the pps output is between +/-40ns. figure 5-1 illustrates quantization error. the top waveform represents the 12.504 mhz clock. the acutime 2000 pps output must be placed on one of the rising edges of this clock. the middle waveform represents the utc/gps on-time mark as determined by the acutime 2000?s gps receiver electronics. the bottom waveform represents the acutime 2000?s pps output, which is output on the clock edge closest to the actual utc/gps on- time mark. figure 5-1 pps quantization error the amount of quantization error present on each pps output pulse is reported in packet 0x8f-ac. this quantization error information can be used to reduce the effective amount of jitter on the pps pulse. 12.504 mhz clock utc or gps pps acutime 2000 pps www.datasheet.co.kr datasheet pdf - http://www..net/ 5-8 acutime 2000 synchronization kit user guide system operation 5 figure 5-2 illustrates the result of removing the quantization error from the pps output in a user system. the top plot shows the offset of the pps output pulse relative to a stable standard such as a cesium atomic clock. the quantization error is responsible for the jagged appearance of the waveform. the middle plot shows the quantization error as reported by the acutime 20000 in packet 0x8f-ac. the bottom plot is the result of subtracting the quantization error from the pps offset. figure 5-2 removing the quantization error from the pps output 0 100 200 300 400 500 time (seconds) -100 -50 0 50 100 pps offset (ns) quantization error (ns) corrected pps offset (ns) -100 -50 0 50 100 -100 -50 0 50 100 0 100 200 300 400 500 time (seconds) 0 100 200 300 400 500 time (seconds) www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 5-9 5 system operation 5.2.5 external event input the acutime 2000 provides an external event input that allows the user to time tag external event pulses. the event capture mechanism is triggered on the low-to-high transition of the external event input. the time tag provides a resolution of 320 nanoseconds and represents the time at which the event pulse occurred at the acutime 2000 connector input. therefore, it is offset by the amount of delay in the cable. the time tag information is reported in packet 0x8f-0b (or 8f-ad). this feature is intended for use with relatively infrequent event pulses. a practical limit on event pulse frequency is about 10 hz. to prevent the acutime 2000 hardware and firmware from being overrun with event pulse inputs, make sure that an event pulse will not occur until the time tag from the previous event pulse reported in packet 0x8f-0b (or 8f-ad) is received. 5.2.6 cable delay compensation the pps output from the acutime 2000 is calibrated to be aligned with utc/gps at the connector. the pps you receive is delayed by the amount of propagation delay in the cable between the acutime 2000 and your equipment. you can compensate for this delay by setting the pps offset field of packet 0x8e-4a. the propagation delay through the cable depends on the cable type used, but in general, the delay is approximately 1.25 nanosecond per foot of cable. negative pps offset values cause the pps output to occur early, which compensates for the propagation delay of the cable. www.datasheet.co.kr datasheet pdf - http://www..net/ 5-10 acutime 2000 synchronization kit user guide system operation 5 5.3 serial data communication when the acutime 2000 has acquired a set of satellites that conforms to the mask and mode settings and has collected a valid ephemeris for each satellite, it automatically commences periodic outputs of gps data and generates a timing pulse (pps). 5.3.1 port b the acutime 2000 outputs periodic tsip health, mode, and time messages on port b. these status messages confirm that the receiver is working. these packets are described in appendix a, trimble standard interface protocol. the factory default port setting is 9600 baud in/out, 8 data bits, odd parity, 1 stop bit. the serial port setting can be changed and stored in serial eeprom using a tsip command. this port can also be configured to transmit timing packets, using packet 8e-a5 to determine which timing packet to output on this port. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 5-11 5 system operation 5.3.2 port a (timing) the acutime 2000 has a dedicated serial port for outputting comprehensive time packets. messages are output after the pps and after external events. the factory default setting is tsip, 9600, 8-odd-1, output only. the host system receives both the pps and the time packet identifying each pulse. use packet 8e-a5 to determine which timing superpacket to output on this port. the acutime 2000 generates a packet in response to the external event input. the event count field in packet 8f-0b (or 8f-ad) increments for each event received. this field resets after a power cycle and rolls over at 65535. the event tag messages are interleaved with the pps messages. pps tags are distinguished by a zero (0) in the event count field. the acutime 2000 accepts external events up to a 10 hertz rate. use packet 8e-a5 to configure this port to output the 8f-0b (or 8f-ad) packet in response to external events. www.datasheet.co.kr datasheet pdf - http://www..net/ 5-12 acutime 2000 synchronization kit user guide system operation 5 5.4 gps timing in many timing applications, such as time/frequency standards, site synchronization systems, wireless voice and data networks, and event measurement systems, gps receivers are used to steer a local reference oscillator. the steering algorithm combines the short-term stability of the oscillator with the long-term stability of the gps pps. an accurate gps pps allows the use of cost-effective crystal oscillators, which have poorer stability than expensive, high-quality oscillators, such as atomic cells. the gps constellation consists of at least 24 orbiting satellites. unlike most telecommunications satellites, gps satellites are not geostationary, so satellites in view are constantly changing. each gps satellite contains four highly-stable atomic clocks, which are continuously monitored and corrected by the gps control segment. consequently, the gps constellation can be considered a set of 24 orbiting "clocks" with worldwide 24-hour coverage. a trimble gps receiver uses the signals from these gps "clocks" to correct its own internal clock, which is not as stable or accurate as the gps atomic clocks. a gps receiver like the acutime 2000 outputs a highly accurate timing pulse (pps) generated by its internal clock, which is constantly corrected using the gps clocks. in the case of the acutime 2000, this timing pulse is synchronized to utc within 50 nanoseconds (one sigma) after survey is complete. in addition to serving as highly-accurate stand-alone time sources, gps receivers are used to synchronize distant clocks in communication or data networks. this is possible because all gps satellites are corrected to a common master clock. therefore, the relative clock error is the same, regardless of which satellites are used. for synchronization applications requiring a common clock, gps is the ideal solution. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 5-13 5 system operation gps time accuracy is affected by the same major source of error that affects position accuracy: selective availability (s/a). the position and time errors are related by the speed of light. therefore, a position error of 100 meters corresponds to a time error of approximately 333 nanoseconds. the gps receiver's clocking rate and software affect pps accuracy. the acutime 2000?s 12.5 mhz clocking rate enables a steering resolution of 80 ns (40 ns). using software algorithms like an overdetermined clock solution, the acutime 2000 mitigates the effects of s/a to achieve a pps accuracy of 50 ns (one sigma) after survey is complete. 5.4.1 timing operation the acutime 2000 automatically outputs a pps and time tag. with an accurate reference position, the acutime 2000 automatically switches to an overdetermined clock mode, activates its t-raim algorithm and outputs a precise pps. the overdetermined clock solution mitigates the effects of s/a. using a simple voting scheme based on pseudo- range residuals, the acutime 2000's integrity algorithm automatically removes the worst satellite with the highest residual from the solution set if that satellite?s residual is above a certain threshold. the acutime 2000's default configuration provides optimal timing accuracy. the only item under user or host control that can affect the acutime 2000?s absolute pps accuracy is the delay introduced by the interface cable. for long cable runs, this delay can be significant (1.25 nanoseconds per foot). tsip packet 8ex4a sets the cable delay parameter, which is stored in non-volatile memory. for the best absolute pps accuracy, adjust the cable delay to match the installed cable length. the cable delay is 1.25 nanoseconds per foot of cable. to compensate for cable delay, use a negative offset to advance the pps output. www.datasheet.co.kr datasheet pdf - http://www..net/ 5-14 acutime 2000 synchronization kit user guide system operation 5 timing pulse output (pps) a pulse-per-second (pps), 1 microsecond-wide pulse is available on the acutime 2000?s interface connector. the pulse is sent once per second and the leading edge of the pulse is synchronized to utc or gps time. the pulse shape is affected by the distributed capacitance of the attached cabling and input circuit. the leading edge is typically less than 20 nanoseconds wide. the pulse's trailing edge should never be used for timing applications. an accurate timing pulse is available only when the acutime 2000 is operating in the static overdetermined clock mode. * note ? gps time differs from utc (universal coordinated time) by a small, sub-microsecond offset and an integer-second offset. the small offset is the steering offset between the gps dod clock ensemble and the utc (nist) clock ensemble. the large offset is the cumulative number of leap seconds since 1 january 1970, which, on 31 december 1998, was increased from 12 to 13 seconds. historically, the offset increases by one second approximately every 18 months, usually just before midnight on 30 june or 31 december. system designers should note whether the output time is utc or gps time. * note ? the event time reported in 8f-0b and 8-ad is corrected for the fractional utc offset if utc pps (default) is selected. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 5-15 5 system operation 5.5 using the acutime 2000 in mobile applications although it is intended primarily for use in static applications, the acutime 2000 can also be used in mobile applications. the factory default settings for the acutime 2000 assume that the antenna is going to be used in a static timing application. to use the acutime 2000 in mobile applications, you must disable the acutime?s self-survey mechanism and ensure that a stored position does not exist in the nonvolatile eeprom. to prepare the acutime 2000 for mobile applications, complete the following steps. make sure that there is no stored position in the nonvolatile eeprom by using command packet 8e-45 with data byte 1 set to 6 (accurate position segment.) this operation clears any stored position from the eeprom. disable the self-survey mechanism using command packet 8e-a9. if not disabled, the self-survey mechanism will automatically survey the antenna?s position and then set the receiver to operate in a static, time-only mode. set the desired position fix mode using command packet bb. after these steps are completed, the acutime 2000 is ready to operate properly in mobile applications. while operating in a mobile application, the acutime 2000 can continue to output a pps pulse as well as timing packets. * note ? the accuracy of the pps output pulse will be degraded by a factor of about 3 when the unit is operated in a mobile application. www.datasheet.co.kr datasheet pdf - http://www..net/ 5-16 acutime 2000 synchronization kit user guide system operation 5 5.6 customizing acutime 2000 operations the acutime 2000 provides a number of user configurable parameters that allow you to customize the operation of the unit. these parameters are stored in a non-volatile memory chip (eeprom) to be retained during loss of power and through resets. at reset or power-up, the acutime 2000 configures itself based on the parameters stored in the eeprom. you can change the values of these parameters to achieve the desired operations using a variety of tsip packets. the acutime 2000 configures itself based on the new parameter immediately, but the new parameter value is not automatically saved to the eeprom. you must direct the acutime 2000 to save the parameters to the eeprom. parameters are grouped into sections of the eeprom called segments. each segment is identified with a number and contains a group of related parameters. to change the parameter values stored in eeprom, send packet 0x8e-26 to direct the acutime 2000 to save the current parameter values in a specified segment in the eeprom. you can also direct the acutime 2000 to set the parameter values to their factory default settings with packet 0x8e-45. when a segment is set to its factory defaults, the contents of the eeprom segment are set and the acutime 2000 configures itself with the default settings. in brief, to customize the acutime 2000 operations for your application: configure the acutime 2000 using tsip command packets until the desired operation is achieved. use tsip packet 0x8e-26 to save the settings in non-volatile memory (eeprom.) the new settings will control the acutime 2000 operations whenever it is reset or power cycled. tables 5-2 through 5-12 list the user configurable parameters by segment number. each table lists the parameter name, its factory default value, and the tsip packet that sets or reads the parameter value (typically, one tsip packet sets or reads several related parameters.) www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 5-17 5 system operation table 5-2 receiver configuration (segment 2) parameter factory default set request report operating dimension 4 (full position 3d) bb bb bb dgps mode 3 (auto dgps/gps) bb bb bb dynamics code 1 (land) bb bb bb elevation mask 0.175 radians (10 degrees) bb bb bb signal level mask 4.0 amu bb bb bb pdop mask 8.0 bb bb bb pdop switch 6.0 bb bb bb foliage mode 0 (never) bb bb bb dgps age limit 30 seconds bb bb bb have reference altitude flag false 2a 2a 4a reference altitude (meters) 0.0 2a 2a 4a table 5-3 oem configuration (segment 3) parameter factory default set request report datum index wgs 84 ellipsoid 8e-14 8e-15 8f-15 position 0x12 35 35 35 velocity 0x02 35 35 35 time 0x01 35 35 35 auxiliary 0x02 35 35 35 super packets output mask (byte 1) 0x32 8e-a5 8e-a5 8f-a5 super packets output mask (byte 2) 0x21 8e-a5 8e-a5 8f-a5 auto tsip output mask 0xfffffffc0 8e-4d 8e-4d 8f-4d www.datasheet.co.kr datasheet pdf - http://www..net/ 5-18 acutime 2000 synchronization kit user guide system operation 5 table 5-4 port a and b configuration (segment 4) parameter factory default set request report input baud rate 9600 bc bc bc output baud rate 9600 bc bc bc parity odd bcbcbc data bits 8 bc bc bc stop bits 1 bc bc bc input protocol none bc bc bc output protocol tsip bc bc bc table 5-5 pps configuration (segment 5) parameter factory default set request report pps enabled switch enabled 8e-4a 8e-4a 8e-4a pps timebase utc 8e-4a 8e-4a 8e-4a polarity true 8e-4a 8e-4a 8e-4a pps offset 0.0 seconds 8e-4a 8e-4a 8e-4a bias uncertainty threshold 300.0 meters 8e-4a 8e-4a 8e-4a pps width 10.0e-6 seconds 8e-4f 8e-4f 8e-4f pps driver switch 3 (at least 1 sv) 8e-4e 8e-4e 8e-4e table 5-6 position information (segment 6) parameter factory default set request report xyz coordinates such that lla coordinates are all zeros 31 have position flag false www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide 5-19 5 system operation the survey operating dimension can be set to auto and 2d if segments are saved (8e-26) while a survey is in process. the receiver uses the dimension setting saved for the next survey. if a reference altitude has been entered and the receiver is set to 2d survey, the reference altitude is used. if a reference altitude has not been entered and the receiver is set to 2d survey, an altitude of 0 is used for 2d survey (not recommended). table 5-7 self-survey configuration (segment 7) parameter factory default set request report survey enable flag true 8e-a6 8e-a6 8f-a6 survey length 2000 8e-a6 8e-a6 8f-a6 survey save flag false 8e-a6 8e-a6 8f-a6 survey operating dimension full position 3d 0xbb 0xbb 0xbb table 5-8 nmea configuration (segment 8) parameter factory default set request report nmea message mask 0x00000020 (zda) 7a 7a 7a nmea message rate 1 7a 7a 7a nmea options 0 7a 7a 7a table 5-9 utc information (segment 11) parameter factory default set request report have_utc false www.datasheet.co.kr datasheet pdf - http://www..net/ 5-20 acutime 2000 synchronization kit user guide system operation 5 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-1 a trimble standard interface protocol the trimble standard interface protocol (tsip) provides commands that the system designer can use to configure a gps receiver for optimum performance in a variety of applications. tsip enables the system designer to customize the configuration of a gps module to meet the requirements of a specific application. tsip is a simple bidirectional, binary packet protocol used in a wide variety of trimble gps receivers. tsip offers a broad range of command packets and report packets that provide the gps user with maximum control over the acutime 2000 receiver. this appendix provides the information needed to make use of the powerful tsip features, enhance overall system performance, and reduce the total development time. the reference tables beginning on page a-5 help you determine which packets apply to your application. for those applications requiring customization, see table a-10 for a detailed description of the key setup parameters. application guidelines are provided for each tsip command packet, beginning on page a-9. a.1 interface scope the trimble standard interface protocol (tsip) is based on the transmission of packets of information between the user equipment (host) and the gps receiver. each packet includes an identification code (1 byte, representing 2 hexadecimal digits) that identifies the www.datasheet.co.kr datasheet pdf - http://www..net/ a-2 acutime 2000 synchronization kit user guide trimble standard interface protocol a meaning and format of the data that follows. each packet begins and ends with control characters. a.1.1 packet structure tsip packet structure is the same for both commands and reports.the packet format is: acutime 2000 synchronization kit user guide a-3 a trimble standard interface protocol double (8 byte real) is sent as a series of eight bytes (a, b, c, d, e, f, g, h); it has a precision of 52 significant bits, a little better than 15 digits. the tsip protocol is the primary protocol used by the acutime 2000 receiver. this document describes in detail all tsip packet identification codes, the format of each packet, and all available information that can be output from the acutime 2000. this manual allows the user to configure the receiver to output information required for a particular application. the receiver transmits some of the information (position and velocity solutions, etc.) automatically when it is available, while other information is transmitted only on request. a.2 physical interface characteristics the acutime 2000 utilizes high-quality serial i/o components to drive the available serial transmit and receive channels. the acutime 2000 is available in rs-232 and rs-422 configurations. this section is provided to provide the user with a complete understanding of the capabilities of each receiver. a.2.1 nomenclature historically, the ports of the smart antenna product lines which include acutis, acutime and palisade products, have been described using letters "a" and "b". the acutime 2000 ports are referenced by letters "a" and "b", conformant to standards established by the palisade product line. table a-1 acutime 2000 port translation table function label internal tsip port b port 0 timing port a port 1 www.datasheet.co.kr datasheet pdf - http://www..net/ a-4 acutime 2000 synchronization kit user guide trimble standard interface protocol a a.2.2 protocol capabilities the i/o ports of the acutime 2000 are highly configurable. port settings are stored in non-volatile memory, and are retained across power outages. for systems with minimal bandwidth for processing serial data streams, the receivers can be configured as silent devices, which only generate i/o when polled. the acutime 2000 receiver can be configured to output various automatic report packets and protocols to satisfy demanding real-time update requirements of complex monitoring systems. event input the acutime 2000 features an event input which can capture and report time stamps with the same precision as the pps signal. primary port features (port b) the acutime 2000 features a primary bi-directional port, which is factory configured as for tsip input and output. secondary port features (port a) the acutime 2000 has a bi-directional, programmable secondary port, that is designated as the timing port. the timing port?s protocol input lines are shared with the event input feature. the receiver can be configured to accept protocol input or event signals, but not both. acutime 2000 cannot generate event time tags if port a is configured for rtcm input. the port can be configured to accept and output data using various protocols as shown in the table below. table a-2 secondary port features port designator input default output default ?port a? tsip, rtcm none tsip, nmea tsip www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-5 a trimble standard interface protocol a.2.3 event input the acutime 2000 receiver is capable of time-stamping external events with high-precision. events are triggered by an input pulse, and can be reported by either or both of two super packets. the output of the event packets can be configured using packet 8e-a5. the data in both packets allows constructing a unique 4-dimensional coordinate identifying each event. event reporting the receivers can output the event reports on any available tsip port. a.3 packets output at power-up the following table lists the messages output by the receiver at power-up. after completing its self-diagnostics, the receiver automatically outputs a series of packets that indicate the initial operating condition of the receiver. messages are output in the following order. upon output of packet 82, the sequence is complete and the receiver is ready to accept commands. table a-3 event packets super packet length description 8f-0b 74 comprehensive time with lla position 8f-ad 22 primary utc time with leap information table a-4 packets output at power-up output id description notes 46 receiver health 4b machine code/status 45 software version www.datasheet.co.kr datasheet pdf - http://www..net/ a-6 acutime 2000 synchronization kit user guide trimble standard interface protocol a a.4 receiver warm start you can warm-start the receiver by sending each of the following commands after the receiver has completed its internal initialization and has output packet 82 (see table a-4). 83 double precision xyz position if single precision is selected, packet 42 is output instead. 84 double precision lla position if single precision is selected, packet 4a is output instead. 82 dgps position fix mode table a-5 receiver warm start commands input id description 2b/23 initial position (lla/ecef) 2e initial time 38 (type 2) almanac (for each sv) 38 (type 3) almanac health 38 (type 4) ionosphere page 38 (type 5) utc correction table a-4 packets output at power-up output id description notes www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-7 a trimble standard interface protocol a.5 default background packets (port b) the acutime 2000 automatically outputs a set of packets on port b that you can monitor for changes in receiver operations, including receiver health, time, almanac pages, and ephemeris updates. these messages are output at the rates indicated in the table below. * note ? the background packets listed in this table are automatically output. background packets can be turned off. for more information on this option, see command packet 8e-4d. table a-6 background packets output id description notes 41 gps time if the receiver's gps clock is set and the receiver is not outputting positions, time is output approximately every 16 seconds. output approximately every 2.5 minutes if the receiver is doing position fixes. 46 receiver health output approximately every 16 seconds, if the receiver is not doing fixes. output approximately every 30 seconds if the receiver is doing position fixes. whenever any bit in the health message changes, receiver health is automatically output. 6d mode packet output approximately every 30 seconds or when a constellation change occurs. www.datasheet.co.kr datasheet pdf - http://www..net/ a-8 acutime 2000 synchronization kit user guide trimble standard interface protocol a a.6 default automatic position and velocity reports the acutime 2000 automatically outputs position and velocity reports at set intervals. report intervals are controlled by packet 35. * note ? when the receiver is in the manual or overdetermined clock mode, it outputs packet 54 to provide the computed clock-only solution. a.7 automatic primary and supplemental timing reports timing packets 8f-ab and 8f-ac are automatically output at 1 hz. these packets are part of the low-latency packet series ab/ac/ad/ ob. see section a.8. table a-7 automatic position and velocity reports output id description 42 single precision xyz position 83 double-precision xyz position 4a single-precision lla position 84 double-precision lla position 43 velocity fix (xyz ecef) 54 bias and bias rate (see note) 56 velocity fix (enu) www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-9 a trimble standard interface protocol a.8 low-latency timing packets the acutime 2000 features a sequence of high-priority timing super packets, which are output within a bounded period of time after the pps. the llt packets offer an advanced data interface for applications requiring accurate data reports in a time constrained environment. the first super packet will start transmission no later than 15?25 ms after the pps transition. the super packets which meet the lltp criteria are in the table below. the packets are listed in order of output priority. output of each packet can be turned on/off by using the mask in packet 8e-a5, but the output order cannot be changed. the packets may also be requested, please refer to the specific packet documentation for details. the receiver will output all other tsip packets after the transmission of llt packet sequence is complete. * note ? only the first packet will meet the lltp specification. all other llt packets will be output immediately after the first llt packet completes. table a-8 low-latency timing packets lltp packet id description request packet id 8f-ab primary timing 8e-ab 8f-ac supplemental timing 8e-ac 8f-ad primary utc time 8e-ad 8f-0b comprehensive time and position 8e-0b www.datasheet.co.kr datasheet pdf - http://www..net/ a-10 acutime 2000 synchronization kit user guide trimble standard interface protocol a a.9 event packets event packets 8f-0b and 8f-ad are output in response to the event input as configrured by packet 8e-a5 a.10 satellite data packets the following packets request data transmitted by the gps satellites and satellite tracking information. table a-9 satellite data packets input id description output id 20 request almanac 40 27 request signal levels 47 28 request gps system message 48 29 request almanac health page 49 2f request utc parameters 4f 38 request/load satellite system data 58 39 set/request satellite disable or ignore health 59 3a request last raw measurement 5a 3b request satellite ephemeris status 5b 3c request tracking status 5c www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-11 a trimble standard interface protocol a.11 customizing receiver operations the following packets let you customize the receiver output for your application. note 1: output is determined by packet 35 settings (see table a-3). table a-10 customizing receiver operations input id description output id 23 set initial position (xyz cartesian ecef) 24 request receiver position fix mode 6d 26 request receiver health 46 and 4b 27 request satellite signal levels 47 2a set altitude for 2-d mode 4a 2b set initial position (lla) 2e set gps time 4e 35 set input/output options 55 7a set/request nmea interval and message mask 7b bb set/request receiver configuration bb bc set/request port configuration bc 8e-14 set/request datum value 8f-14 8e-4a set/request pps characteristics 8f-4a 8e-a5 set/request packet broadcast mask 8f-a5 8e-a6 issue self-survey command 8f-a6 www.datasheet.co.kr datasheet pdf - http://www..net/ a-12 acutime 2000 synchronization kit user guide trimble standard interface protocol a the following packets let you customize receiver operations. table a-11 advanced packets input id description output id 1e clear memory, reset (note 1) 25 soft reset and self test (note 1) 2d request oscillator offset 4d 39 satellite disable or ignore health 59 (note 2) bb set receiver configuration parameters bb 8e-4a set pps characteristics 8f-4a 8e-4e set pps output option 8f-4e 8e-4f set pps width (acutime 2000 only) 8f-4f 8e-20 set fixed point superpacket output 8f-20 note 1: output is determined by packet 35 settings. for packets 1e and 25, see table a-4 to determine which packets are output at power-up. note 2: not all modes of packet 39 cause a reply (see the description for packet 39, page a-34) . www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-13 a trimble standard interface protocol a.12 command packets sent to the receiver table a-12 summarizes the command packets sent to the receiver. it includes a short description of each packet and the associated output packet. in some cases, the response packets depend on user-selected options. these selections are described beginning on page a-18. table a-12 command packets sent to the receiver input packet description output id 1d oscillator offset 1e reset receiver (note 1) 1f software version 45 20 almanac 40 21 current gps time 41 22 fix mode select (note 2) 23 initial position (xyz cartesian ecef) 24 receiver position fix mode 6d 25 soft reset and self-test (note 1) 26 receiver health 46, 4b 27 signal levels 47 28 gps system message 48 29 almanac health page 49 2a altitude for 2-d mode 4a 2b initial position (lla) 2c operating parameters 4c 2d oscillator offset 4d 2e set gps time 4e 2f utc parameters 4f 31 accurate initial position (xyz cartesian ecef) 32 accurate initial position (lla) 34 satellite # for 1-sv mode 35 i/o options 55 37 status and values of last position and velocity 57 (note 4) 38 load satellite system data 58 www.datasheet.co.kr datasheet pdf - http://www..net/ a-14 acutime 2000 synchronization kit user guide trimble standard interface protocol a 39 satellite enable/disable and health heed/ignore 59 (note 3) 3a last raw measurement 5a 3b satellite ephemeris status 5b 3c tracking status 5c 3d timing port configuration 3d 3f-11 request eeprom segment status 5f-11 7a set/request nmea interval and message mask 7b bb set receiver configuration bb bc set port configuration bc 8e-0b 8f-0b output configuration 8f-a5/8f-0b 8e-14 set new datum 8f-14 8e-15 current datum values 8f-15 8e-20 last fix (fixed point) 8f-20 8e-26 write receiver configuration eeprom 8f-26 8e-41 manufacturing parameters 8f-41 8e-42 production parameters 8f-42 8e-45 revert segments to default settings 8f-45 8e-4a set/request pps characteristics 8f-4a 8e-4b survey limit 8f-4b 8e-4d packet output mask 8f-4d 8e-4e set pps output option 8f-4e 8e-4f set pps width (acutime 2000 only) 8f-4f 8e-a5 set or request packet broadcast mask 8f-a5 8e-a6 issue self-survey command 8f-a6 8e-ab set/request primary timing packet 8f-ab 8e-ac set/request supplemental timing packet 8f-ac 8e-ad 8f-ad output configuration 8f-a5/8f-ad table a-12 command packets sent to the receiver (continued) input packet description output id www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-15 a trimble standard interface protocol note 1: output is determined by packet 35 settings. see table to determine which messages are output at power-up. note 2: entering 1sv mode initiates automatic output of packet 54. note 3: not all packet 39 operations have a response. see packet 39 description. note 4: output is determined by packet 35 settings. a.13 report packets sent by the gps receiver to the user table a-13 summarizes the packets output by the receiver. it includes the output packet id, a short description of each packet, and the associated input packet. in some cases, the response packets depend on user-selected options. these selections are covered in the packet descriptions beginning on page a-18. table a-13 report packets sent by gps receiver to user output id packet description input 3d timing port configuration 3d 40 almanac data for one satellite 20 41 gps time 21 42 single-precision xyz ecef position 37 43 velocity fix (xyz ecef) 37 45 software version information 1f 46 health of receiver 26 47 signal level for all satellites 27 48 gps system message 28 49 almanac health for all satellites 29 4a single-precision lla position 37 4b machine code/status 26 4c report operating parameters 2c 4d oscillator offset 2d 4e response to set gps time 2e 4f utc parameters 2f 54 one-satellite bias and bias rate 22 www.datasheet.co.kr datasheet pdf - http://www..net/ a-16 acutime 2000 synchronization kit user guide trimble standard interface protocol a 55 i/o options 35 56 velocity fix (enu) 37 57 information about last computed fix 37 58 gps system data/acknowledge 38 59 satellite enable/disable and health heed/ignore 39 5a raw measurement data 3a 5b satellite ephemeris status 3b 5c satellite tracking status 3c 5f-11 request eeprom segment status 3f-11 6d all-in-view satellite selection 24 7b nmea interval and message mask 7a 83 double-precision xyz position 37 84 double-precision lla position 37 bb receiver configuration bb bc port configuration bc 8f-0b comprehensive time auto/event 8f-14 current datum values 8e-14 8f-20 last fix with extra information (fixed point) 8e-20 8f-26 response to save eeprom segments 8e-26 8f-41 manufacturing parameters 8e-41 8f-42 production parameters 8e-42 8f-45 response to revert segments to default 8e-45 8f-4a pps characteristics 8e-4a 8f-4b survey limit 8e-4b 8f-4d automatic packet output mask 8e-4d 8f-4e pps output option 8e-4e 8f-4f set pps width 8e-4f 8f-a5 packet broadcast mask 8e-a5 8f-a6 response to self-survey command 8e-a6 table a-13 report packets sent by gps receiver to user (continued) output id packet description input www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-17 a trimble standard interface protocol 8f-ab primary timing packet 8e-ab 8f-ac supplemental timing packet 8e-ac 8f-ad utc event time event/auto table a-13 report packets sent by gps receiver to user (continued) output id packet description input www.datasheet.co.kr datasheet pdf - http://www..net/ a-18 acutime 2000 synchronization kit user guide trimble standard interface protocol a a.14 packet descriptions command packets are sent from an external device, such as a computer or terminal, to the receiver when requesting report packets, setting receiver parameters, or performing receiver command operations such as resetting the receiver. many command packets have a corresponding report packet, which is sent to the external device in response to the command packet. some commands perform discrete operations and have no matching report packet. 0x1d command packet 1d oscillator offset this packet commands the gps receiver to set or clear the oscillator offset in battery backed memory. this is normally used for servicing the unit. to set the oscillator offset, four data bytes are sent: the oscillator offset in hertz relative to l1 as a single real value. the oscillator offset is automatically updated when the receiver is doing fixes. * note ? use of this packet is for diagnostic purposes only and is not recommended for the user. table a-14 command packet 1d - clear oscillator offset byte item type value response 0 operation byte "c," 43 hex clear the oscillator offset table a-15 command packet 1d - set oscillator offset byte item type value response 0-3 offset single offset in hertz set the oscillator offset www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-19 a trimble standard interface protocol 0x1e command packet 1e initiate cold or factory reset this command packet tells the receiver to perform either a cold reset or a factory reset. a cold reset clears all navigation data (for example, almanac, and ephemeris) stored in ram and is equivalent to a power cycle. a factory reset also restores the factory defaults for all configuration and navigation parameters stored in non-volatile memory. this packet can affect separately the configuration parameters and navigation parameters. it contains one data byte equal to one of the following ascii letters: ?k?, ?f?, ?c?,?n?, or ?r?. i caution ? the factory reset commands 0x1e-?f? and 0x1e-?r? will delete the stored position and cause a self-survey to restart. all almanac, ephemeris, current position, mode, and communication port setup information stored in ram is lost by the execution of these commands. 0x1f command packet 1f software versions request this packet requests information about the version of software running in the navigation and signal processors. this packet contains no data bytes. the gps receiver returns packet 45. table a-16 command packet 1e byte item type value response 0 rest byte ?k? (0x4b) ?f? (0x46) ?c? (0x43) ?n? (0x4e) ?r? (0x52) cold reset factory reset compatibility re-start for the palisade firmware version v7.02 clear navigation data in eeprom and cold reset set configuration parameters in eeprom to factory defaults and cold reset www.datasheet.co.kr datasheet pdf - http://www..net/ a-20 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x20 command packet 20 almanac request this packet requests almanac data for one satellite from the gps receiver. this packet contains one data byte specifying the satellite prn number. the gps receiver returns packet 40 hex. 0x21 command packet 21 current time request this packet requests current gps time. this packet contains no data. the gps receiver returns packet 41 hex. 0x23 command packet 23 initial position (xyz cartesian ecef) command this packet provides the gps receiver with an approximate initial position in xyz coordinates. this packet is useful if the user has moved more than about 1,000 miles since the previous fix. * note ? the gps receiver can initialize itself without any data from the user; this packet merely reduces the time required for initialization. this packet is ignored if the receiver is already calculating positions. the origin is the earth?s center. the x-axis points toward the intersection of the equator and the greenwich meridian, the y-axis points toward the intersection of the equator and the 90 o meridian, and the z-axis points toward the north pole. the cold-start default lla (not xyz) position is 0, 0, 0. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-21 a trimble standard interface protocol the data format is shown in the table below. 0x24 command packet 24 gps receiver position fix mode request this packet requests the current position fix mode of the gps receiver. this packet contains no data. the gps receiver returns packet 6d. 0x25 command packet 25 initiate soft reset / self test command this packet commands the gps receiver to perform a software reset. the gps receiver performs a self-test as part of the reset operation. this packet contains no data. following completion of the reset, the receiver outputs the startup messages (see table a-1). the receiver retains the time, survey position, port configuration, and almanac contents during this operation. * note ? the gps receiver sends packet 45 only on power-up and reset (or on request). if packet 45 appears unrequested, either the gps receiver power was cycled or the gps receiver was reset. 0x26 command packet 26 health request this packet requests health and status information from the gps receiver. this packet contains no data. the gps receiver returns packets 46 and 4b. table a-17 command packet 23 byte item type units 0-3 x single meters 4-7 y single meters 8-11 z single meters www.datasheet.co.kr datasheet pdf - http://www..net/ a-22 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x27 command packet 27 signal levels request this packet requests signal levels for all satellites currently being tracked. this packet contains no data. the gps receiver returns packet 47. 0x28 command packet 28 gps system message request this packet requests the gps system ascii message sent with the navigation data by each satellite. this packet contains no data. the gps receiver returns packet 48. 0x29 command packet 29 almanac health page request this packet requests the health page from the almanac. this packet contains no data. the gps receiver returns packet 49. 0x2a command packet 2a altitude for 2-d mode command this packet provides the altitude to be used for 2-dimensional navigation mode. this packet contains one single number (4 bytes) specifying the altitude in meters, using the wgs-84 model of the earth or msl geoid altitude, depending on i/o options (set by packet 35). the gps receiver returns packet 4a. it is recommended that the user upload the reference altitude before the receiver starts doing position fixes. if an altitude is not provided, the receiver will use the altitude of the previous 3-d fix (altitude-hold mode). sending packet 2a with one data byte equal to 0xff will cancel altitude-set mode and return the reference altitude to 0. the altitude setting is stored in non-volatile memory. packet 0x8e-26 can be used to write receiver configuration to eeprom. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-23 a trimble standard interface protocol to use the fixed altitude survey mode, the receiver must be configured to manual 2-d navigation mode using packet bb. the reference altitude will be used in 2-d survey from both warm and cold starts. * note ? if the receiver altitude is set above 18,000 m, the receiver will be forced to reset each time it acquires satellites. this is implemented to conform with the cocom industry standard. www.datasheet.co.kr datasheet pdf - http://www..net/ a-24 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x2b command packet 2b initial position (latitude, longitude, altitude) command this packet provides the gps receiver with an approximate initial position in latitude and longitude coordinates (wgs-84). this packet is useful if the user has moved more than about 1,000 miles since the previous fix. * note ? the gps receiver can initialize itself without any data from the user; this packet merely reduces the time required for initialization. this packet is ignored if the receiver is already calculating positions. the cold-start default lla position is 0, 0, 0. the data format is shown below. the gps receiver returns packet 4b. 0x2d command packet 2d oscillator offset request this packet requests the calculated offset of the gps receiver master oscillator. this packet contains no data. the gps receiver returns packet 4d hex. this packet is used mainly for service. 0x2e command packet 2e gps time command this packet provides the approximate gps time of week and the week number to the gps receiver. the gps receiver returns packet 4e. the table a-18 command packet 2b byte item type units 0-3 latitude single radians, north 4-7 longitude single radians, east 8-11 altitude single meters www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-25 a trimble standard interface protocol data format is shown below. the gps week number reference is week # 0 starting january 6, 1980. the seconds count begins at the midnight which begins each sunday morning. this packet is ignored if the receiver has already calculated the time from tracking a gps satellite. 0x2f command packet 2f utc parameters request this packet requests the current utc-gps time offset (leap seconds). the packet has no data. the receiver returns packet 4f. 0x31 command packet 31 accurate initial position (xyz cartesian ecef) command this packet is identical in content to packet 23. this packet provides an initial position to the gps receiver in xyz coordinates. however, the gps receiver assumes the position provided in this packet to be accurate. this packet is used for satellite acquisition aiding in systems where another source of position is available and in time transfer (one-satellite mode) applications. for acquisition aiding, the position provided by the user to the gps receiver in this packet should be accurate to a few kilometers. for high-accuracy time transfer, position should be accurate to a few meters. traim flags come on if this position is not accurate enough. inputting accurate position sets the self-survey completion state to 100%. the uploaded position is not stored in eeprom unless it is stored with command packet 8e-26. the input position is reported by packet 8f-ac. table a-19 command packet 2e byte item type units 0-3 gps time of week single seconds 4-5 gps week number integer weeks www.datasheet.co.kr datasheet pdf - http://www..net/ a-26 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x32 command packet 32 accurate initial position (latitude, longitude, altitude) command this packet is identical in content to packet 2b. this packet provides the gps receiver with an initial position in latitude, longitude, and altitude coordinates. however, the gps receiver assumes the position provided in this packet to be accurate. this packet is used for satellite acquisition aiding in systems where another source of position is available and in time transfer (one-satellite mode) applications. for acquisition aiding, the position provided by the user to the gps receiver in this packet should be accurate to a few kilometers. for high-accuracy time transfer, position should be accurate to a few meters. traim flags come on if this position is not accurate enough. inputting accurate position sets the self-survey completion state to 100%. the uploaded position is not stored in eeprom unless it is stored with command packet 8e-26. the input position is reported by packet 8f-ac. 0x34 command packet 34 satellite number for one-satellite mode command this packet allows the user to control the choice of the satellite to be used for the 1d timing mode. this packet contains one byte. if the byte value is 0, the gps receiver automatically chooses the usable satellite with the highest elevation above the horizon. this automatic selection of the highest satellite is the default action, and the gps receiver does this unless it receives this packet. if the byte value is from 1 to 32, the packet specifies the prn number of the satellite to be used. a subsequent value of 0 will return the receiver to automatic 1-sv mode. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-27 a trimble standard interface protocol 0x35 command packet 35 i/o option flags command this packet requests the current i/o option states and optionally allows the i/o option states to be set as desired. to request the option states without changing them, the user sends the packet with no data bytes included. to change any option states, the user includes 4 data bytes with the values indicated below in the packet. the i/o options, their default states, and the byte values for all possible states are shown below. these option states are held in non-volatile memory. the gps receiver returns packet 55. use packet 8e-26 to save settings to eeprom. these abbreviations apply: alt - altitude ecef - earth-centered, earth-fixed xyz - cartesian coordinates lla - latitude, longitude, altitude hae - height above ellipsoid wgs-84 - earth model (ellipsoid) msl geoid - earth mean sea level mode utc - universal coordinated time www.datasheet.co.kr datasheet pdf - http://www..net/ a-28 acutime 2000 synchronization kit user guide trimble standard interface protocol a table a-20 command packet 35 byte parameter name bit position default bit value option associated packets 0 position 0 (lsb) 0 xyz ecef output 0: off, 1: on 42 or 83 1 1 lla output 0: off, 1: on 4a or 84 2 0 lla alt output 0: hae (current datum) 1: msl geoid 4a or 84 30alt input 0: hae (current datum) 1: msl geoid 2a 41 precision-of-position output 0: single-precision packet 42 and/or 4a. 1: double-precision packet 83 and/or 84 5 0 8f-20 output 0: off 1: on 6-7 0 unused 1 velocity 0 0 xyz ecef output 0: off, 1: on 43 1 1 enu output 0: off, 1: on 56 2-7 0 unused 2 timing 0 1 time type 0: gps time, 1: utc 1 0 fix computation time 0: asap 1: next integer sec 2 0 fix output time 0: when computed 1: only on request 37 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-29 a trimble standard interface protocol packet 35 is used to control the format and timing of the position and velocity output. bytes 0-1 bytes 0 and 1 control the message output format. byte 2 byte 2 contains the five time parameters described below: time type - this bit defines whether the time tags associated with a position fix are in gps time or utc time. the default is utc time. fix computation time - this bit controls the time and frequency of position fixes. the default is asap. 2 timing 3 0 synchronized measurements 0: off 1: on n/a 4 0 minimize projection 0: off, 1: on n/a 5-7 0 unused 3 auxiliary 0 0 raw measurements 0: off, 1: on 5a 1 1 doppler smoothed codephase 0: raw, 1: smoothed 5a 2-7 unused table a-20 command packet 35 (continued) byte parameter name bit position default bit value option associated packets www.datasheet.co.kr datasheet pdf - http://www..net/ a-30 acutime 2000 synchronization kit user guide trimble standard interface protocol a alternatively, in the integer second mode, the most recent measurements are projected to next integer second, and the solution is then valid at this time. the benefit of this mode is the standard fix time and a 1 hz output rate. the drawbacks are that some measurement projection is performed and that the fix may be slightly older than with the default option. this mode also conforms to the output rate of nmea. output time - this bit defines whether fixes are automatically output when computed or only sent in response to a packet 37 request. the default is automatic output. synchronized measurements - this bit controls whether all satellite range measurements are required to have the same time tag. the default is off. slightly older measurements are tolerated (on the order of 3-5 seconds) to provide solutions when obscurations make it impossible to obtain exactly concurrent measurements from each satellite. when this bit is on, all measurements are required to have the same time tag. this mode is used only when the user application requires all satellite measurements to be identical to the position time tag. if a satellite that is in the selected set for the solution is lost, then no fix will be made until a new selection is made. the synchronized measurement mode combined with the minimized projection timing mode (see next paragraph) allows absolutely no measurement projection. however, obscurations may reduce the fix density when there are limited satellites. use this mode cautiously. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-31 a trimble standard interface protocol minimized projection - this bit controls the time of the position fix relative to the time of the satellite range measurements. the default mode is off. in this mode, the time of solution is the time at which the gps position fix is computed. thus, all measurements are projected by an interval which is roughly the amount of time it takes to compute the solution. this approach minimizes the latency between the time tag of the computed solution and the solution output. the drawback is that the measurement projection (which is only about 100 ms) may induce some error during high accelerations. alternatively, when minimized projection is on, the time of the solution is the time of the most recent measurements. thus, if all measurements are taken at exactly the same time, there is no measurement projection. if a selected satellite's measurement time lags the most recent measurement, then it is projected to this time. the difference is that the fix will have more latency than a fix provided with the above timing option. this is the best choice for users performing non real- time error analysis, or non real-time dgps solution-space corrections. this is also the preferable mode for users integrating gps with other sensors, where communication lags are the dominant latencies, and thus the time lag between the applicability and availability of the fix is small. byte 3 byte 3, the auxiliary byte, controls the output of additional fix data. it contains two control bits: bit 0 controls the output of raw measurements (packet 5a). bit 1 controls whether the raw measurements output in packet 5a are doppler smoothed. www.datasheet.co.kr datasheet pdf - http://www..net/ a-32 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x37 command packet 37 last position and velocity request this packet requests information regarding the last position fix. the gps receiver returns packet 57 and the appropriate position packet 42 or 4a, or 83 or 84, and the appropriate velocity packet 43 or 56, based on the i/o options in effect. in timing mode, the gps receiver returns packets 57 and 54. 0x38 command packet 38 download and upload satellite system data this packet requests current satellite data (almanac, ephemeris, etc.) or permits loading initialization data from an external source (for example, by extracting initialization data from an operating gps receiver via a data logger or computer and then using that data to initialize a second gps receiver unit). the gps receiver returns packet 58. * note ? the gps receiver can initialize itself without any data from the user; it just requires more time. to request data without loading data, use only bytes 0 through 2. to load data, use all bytes. i caution ? proper structure of satellite data is critical to receiver operation. requesting data is not hazardous; loading data improperly is hazardous. use this packet only with extreme caution. the data should not be modified in any way. it should only be retrieved and stored for later reload. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-33 a trimble standard interface protocol table a-21 command packet 38 byte item type value meaning 0 operation byte 1 2 request data from receiver load data into receiver 1 type of data byte 1 2 3 4 5 6 not used almanac health page, t_oa, wn_oa ionosphere utc ephemeris 2 sat prn# byte 0 1-32 data that is not satellite-id specific satellite prn number 3 length (n) byte number of bytes of data to be loaded 4 to n+3 data n bytes www.datasheet.co.kr datasheet pdf - http://www..net/ a-34 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x39 command packet 39 satellite attribute database command normally the gps receiver selects only healthy satellites (based on transmitted values in the ephemeris and almanac) that satisfy all mask values for use in the position solution. this packet allows you to override the internal logic and force the receiver to either unconditionally disable a particular satellite or to ignore a bad health flag. the gps receiver returns packet 59 for operation modes 3 and 6 only. at power-on and after a reset the default values are set for all satellites. i caution ? ignoring health can cause the gps receiver software to fail, as an unhealthy satellite may contain defective data. use extreme caution in ignoring satellite health. table a-22 command packet 39 byte item type value meaning 0 operation byte 1 2 3 4 5 6 enable for selection (default) disable for selection request enable or disable status of all 32 satellites heed health on satellite (default) ignore health on satellite request heed or ignore health on all 32 satellites 1 satellite # byte 0 1-32 all 32 satellites any one satellite prn number www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-35 a trimble standard interface protocol 0x3a command packet 3a last raw measurement request this packet requests the most recent raw measurement data for one specified satellite. the gps receiver returns packet 5a if data is available. 0x3b command packet 3b satellite ephemeris status request this packet requests the current status of satellite ephemeris data. the gps receiver returns packet 5b if data is available. table a-23 command packet 3a byte item type value meaning 1 satellite # byte 0 1-32 all satellites in the current tracking set desired satellite table a-24 command packet 3b byte item type value meaning 1 satellite # byte 0 1-32 all satellites for which ephemeris data is available desired satellite www.datasheet.co.kr datasheet pdf - http://www..net/ a-36 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x3c command packet 3c satellite tracking status request this packet requests the current satellite tracking status. the gps receiver returns packet 5c if data is available. table a-25 command packet 3c byte item type value meaning 1 satellite # byte 0 1-32 all satellites in the current tracking set desired satellite www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-37 a trimble standard interface protocol 0x3d command packet 3d timing port configuration command this packet is superceded by 0xbc. 0x3f-11 command packet 3f-11 eeprom segment commands this command packet requests the status of the eeprom segments and clears the eeprom status minor alarm bit (bit 10) in the supplemental timing packet 8f-ac. the gps receiver replies with report packet 5f-11. 0x40 report packet 40 almanac data page report this packet provides almanac data for a single satellite. the gps receiver sends this packet on request (packet 20 hex) and optionally, when the data is received from a satellite. the data format is shown below. table a-26 command packet 3f-11 byte item type value meaning 0 subcode byte 0x11 eeprom segment status table a-27 report packet 40 byte item type units 0 satellite byte (identification number) 1-4 t_zc single seconds 5-6 week number integer weeks 7-10 eccentricity single (dimensionless) 11-14 t_oa single seconds 15-18 i_o single radians 19-22 omega_dot single radians/second 23-26 square_root_a single (meters) 1/2 www.datasheet.co.kr datasheet pdf - http://www..net/ a-38 acutime 2000 synchronization kit user guide trimble standard interface protocol a t_zc is normally positive. if no almanac data is available for this satellite, then t_zc is negative. t_zc and the week number in this packet refer to the z-count time and week number at the time the almanac was received. the remaining items are described in the icd-gps-200. 0x41 report packet 41 gps time report this packet provides the current gps time of week and the week number. the gps receiver sends this packet in response to packet 21 and during an update cycle. update cycles occur approximately every 15 seconds when not doing fixes and occur approximately every 150 seconds when doing fixes. the data format is shown below. * note ? gps time differs from utc by a variable integral number of seconds. utc = (gps time) - (gps/utc offset). 27-30 omega_0 single radians 31-34 omega single radians 35-38 m_0 single radians table a-28 report packet 41 byte item type units 0-3 gps time of week single seconds 4-5 gps week number integer weeks 6-9 gps/utc offset single seconds table a-27 report packet 40 (continued) byte item type units www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-39 a trimble standard interface protocol i caution ? gps week numbers run from 0 to 1023 and then cycles back to week #0. week #0 began january 6, 1980. another week #0 began august 22, 1999. the receiver automatically adds 1024 to the gps week number after august 21, 1999, and reports the cumulative week number. the seconds count begins with "0" each sunday morning at midnight gps time. a negative indicated time-of-week indicates that time is not yet known; in that case, the packet is sent only on request. the following table shows the relationship between the information in packet 41, and the packet 46 status code. * note ? before using the gps time, verify that the packet 46 status code is 0x00 ("doing position fixes"). this ensures the most accurate gps time. table a-29 relationship between packet 41 and packet 46 approximate time accuracy time source sign (tow) packet 0x46 status code none no time at all ? 0x01 unknown approximate time from real-time clock or packet 2e + 0x01 20 to 50 msec + clock drift time from satellite + not 0x01 full accuracy time from gps solution + 0x00 www.datasheet.co.kr datasheet pdf - http://www..net/ a-40 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x42 report packet 42 single-precision position fix, xyz ecef report this packet provides current gps position fix in xyz ecef coordinates. if the i/o "position" option is set to "xyz ecef" and the i/o "precision-of-position output" (packet 35) is set to single- precision, and the packet is masked for output by packet 8e-4d, then the gps receiver sends this packet each time a fix is computed. the data format is shown below. the time-of-fix is in gps time or utc as selected by the i/o "timing" option. at start-up, this packet or packet 83 is also sent with a negative time-of-fix to report the current known position. packet 83 provides a double-precision version of this information. table a-30 report packet 42 byte item type units 0-3 x single meters 4-7 y single meters 8-11 z single meters 12-15 time-of-fix single seconds www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-41 a trimble standard interface protocol 0x43 report packet 43 velocity fix, xyz ecef report this packet provides current gps velocity fix in xyz ecef coordinates. if the i/o "velocity" option (packet 35) is set to "xyz ecef ", and the packet is masked for output by packet 8e-4d, then the gps receiver sends this packet each time a fix is computed. the data format is shown below. the time-of-fix is in gps time or utc as selected by the i/o "timing" option. table a-31 report packet 43 byte item type units 0-3 x velocity single meters/second 4-7 y velocity single meters/second 8-11 z velocity single meters/second 12-15 bias rate single meters/second 16-19 time-of-fix single seconds www.datasheet.co.kr datasheet pdf - http://www..net/ a-42 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x45 report packet 45 software version information report this packet provides information about the version of software in the navigation and signal processors. the gps receiver sends this packet after power-on and in response to packet 1f. the first five bytes refer to the navigation processor and the second five bytes refer to the signal processor. table a-32 report packet 45 byte item type 0 major version number byte 1 minor version number byte 2month byte 3day byte 4 year number minus 1900 byte 5 major revision number byte 6 minor revision number byte 7month byte 8day byte 9 year number minus 1900 byte www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-43 a trimble standard interface protocol 0x46 report packet 46 health of receiver report this packet provides information about the satellite tracking status and the operational health of the receiver. the receiver sends this packet after power-on or software-initiated resets, in response to packet 26, during an update cycle, when a new satellite selection is attempted, and when the receiver detects a change in its health. packet 4b is always sent with this packet. the data format is given in the following table. table a-33 report packet 46 byte item type value meaning 0 status code byte 00 hex doing position fixes 01 hex do not have gps time yet 03 hex pdop is too high 08 hex no usable satellites 09 hex only 1 usable satellite 0a hex only 2 usable satellites 0b hex only 3 usable satellites 0c hex the chosen satellite is unusable 1 error codes byte see table a-34 www.datasheet.co.kr datasheet pdf - http://www..net/ a-44 acutime 2000 synchronization kit user guide trimble standard interface protocol a the error codes in byte 1 of packet 46 are encoded into individual bits within the byte. the bit positions and their meanings are shown in table a-34. note 1: after this error is detected, the bit remains set until the receiver is reset. note 2: this bit is "1" if the last computed reference frequency error indicated that the reference oscillator is out of tolerance. (packet 2d requests the oscillator offset and packet 4d returns the oscillator offset to the user.) table a-34 report packet 46 error code bit position meaning if bit value = 1 0 (lsb) (unused) 1 signal processor error (note 1) 2 alignment error, channel or chip 1 (note 1) 3 alignment error, channel or chip 2 (note 1) 4 antenna feed line fault (open or short) 5 excessive reference frequency error (note 2) 6 (unused) 7 (msb) (unused) www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-45 a trimble standard interface protocol 0x47 report packet 47 signal levels for all satellites report this packet provides received signal levels for all satellites currently being tracked or on which tracking is being attempted (that is, above the elevation mask and healthy according to the almanac). the receiver sends this packet only in response to packet 27. table a-35 shows the data format. up to 8 satellite number/signal level pairs may be sent, indicated by the count field. signal level is normally positive. if it is zero then that satellite has not yet been acquired. if it is negative then that satellite is not currently in lock. the absolute value of signal level field is the last known signal level of that satellite. the signal level provided in this packet is a linear measure of the signal strength after correlation or de-spreading. 0x48 report packet 48 gps system message report this packet provides the 22-byte ascii message carried in the gps satellite navigation message. the receiver sends this packet in response to packet 28 and when this data is received from a satellite. the message is effectively a bulletin board from the air force to gps users. the format is free-form ascii. the message may be blank. table a-35 report packet 47 byte item type 0 count byte 1 satellite number 1 byte 2-5 signal level 1 single 6 satellite number 2 byte 7-10 signal level 2 single (etc.) (etc.) (etc.) www.datasheet.co.kr datasheet pdf - http://www..net/ a-46 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x49 report packet 49 almanac health page report this packet provides health information on all 32 satellites. packet data consists of 32 bytes each containing the 6-bit health from almanac page 25. the first byte is for satellite #1, and so on. the receiver sends this packet in response to packet 29 and when this data is received from a satellite. in each data byte of this packet, a value "0" indicates that the satellite is healthy; all other values indicate that the satellite is unhealthy. 0x4a report packet 4a reference altitude or single-precision lla position fix report the reference altitude variation of the packet is returned in response to command packet 2a when setting or requesting reference altitude. table a-36 report packet 49 byte item 0 health of satellite #1 1 health of satellite #2 - - - - - - - - - - - - - - - - - - 31 health of satellite #32 table a-37 report packet 4a ? report reference altitude byte item type units 0-3 altitude single meters above wgs-84 or msl 4-7 reserved single reserved 8 reserved byte reserved www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-47 a trimble standard interface protocol the single-precision lla position fix variation of the packet provides current gps position fix in lla (latitude, longitude, and altitude) coordinates. if the i/o "position" option is set to "lla" and the i/o "precision-of-position output" is set to single-precision, and the packet is masked with packet 8e-4d, then the receiver sends this packet each time a fix is computed. the data format is shown below. the lla conversion is done according to the datum selected using packet 8e-14. the default is wgs-84. altitude is referred to the wgs-84 ellipsoid or the msl geoid, depending on which i/o "lla altitude" option is selected. the time-of-fix is in gps time or utc, depending on which i/o "timing" option is selected. this packet also is sent at start-up with a negative time-of-fix to report the current stored position. packet 84 provides a double-precision version of this information. i caution ? when converting from radians to degrees, significant and readily visible errors will be introduced by use of an insufficiently precise approximation for the constant (pi). the value of the constant pi as specified in icd-gps-200 is 3.1415926535898. the msl option is only valid with the wgs-84 datum. when using other datums, only the hae option is valid. table a-38 report packet 4a ? report single-precision lla position byte item type units 0-3 latitude single radians; + for north, - for south 4-7 longitude single radians; + for east, - for west 8-11 altitude single meters 12-15 clock bias single meters 6-19 time-of-fix single seconds www.datasheet.co.kr datasheet pdf - http://www..net/ a-48 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x4b report packet 4b machine/code id and additional status report the receiver transmits this packet in response to packets 25 and 26 and following a change in state. this packet identifies the receiver and may present error messages. packet 46 is always sent with this packet. the machine id can be used by equipment communicating with the receiver to determine the type of receiver to which the equipment is connected. then the interpretation and use of packets can be adjusted accordingly. the status codes are encoded into individual bits within the bytes. the bit positions and their meanings are shown below. table a-39 report packet 4b byte item type/ value status/meaning 0 machine id byte 0x61 =acutime 2000 1 status 1 byte the status 1 codes are encoded into individual bits within the byte 2 status 2 byte super packets are supported. table a-40 byte 1 bit encoding ? status 1 status 1 bit position meaning if bit value = 1 0 (lsb) (not used) 1 (not used) 2 (not used) 3 the almanac stored in the receiver is not complete and current 4-7 not used www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-49 a trimble standard interface protocol 0x4c report packet 4c operating parameters report this packet provides several operating parameter values of the receiver. the receiver sends this packet in response to packet 2c. the data string is four single values. the dynamics code indicates the expected vehicle dynamics and is used to assist the initial solution. the elevation angle mask determines the lowest angle at which the receiver tries to track a satellite. the signal level mask sets the required signal level for a satellite to be used for position fixes. the pdop mask sets the maximum pdop with which position fixes are calculated. the pdop switch sets the threshold for automatic 3- d/2-d mode. if 4 or more satellites are available and the resulting pdop is not greater than the pdop mask value, then 3-dimensional fixes are calculated. this information is stored in non-volatile memory. table a-41 report packet 4c byte item type, units default value, velocity 0 dynamics code byte land (0) value left unchanged (1) land, <120 knots (2) sea, <50 knots (3) air, <800 knots (4) static, stationary 1-4 elevation angle mask single, radians 0.1745 (or 10) 5-8 signal level mask single/--- 4.0 9-12 pdop mask single/--- 8.0 13-16 pdop switch (3-d or 2-d) single/--- 6.0 www.datasheet.co.kr datasheet pdf - http://www..net/ a-50 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x4d report packet 4d oscillator offset this packet provides the current value of the receiver master oscillator offset in hertz at carrier. this packet contains one single number (4 bytes). the receiver sends this packet in response to packet 2d. 0x4e report packet 4e gps time set acknowledgment indicates whether the receiver accepted the time given in a set gps time packet. the receiver sends this packet in response to packet 2e. this packet contains one byte. table a-42 report packet 4e value meaning ascii "y" the receiver accepts the time entered via packet 2e. the receiver has not yet received the time from a satellite. ascii "n" the receiver does not accept the time entered via packet 2e. the receiver has received the time from a satellite and uses that time. the receiver disregards the time in packet 2e. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-51 a trimble standard interface protocol 0x4f report packet 4f utc parameters report this packet is sent in response to command packet 2f and contains 26 bytes. it reports the utc information broadcast by the gps system. for details on the meanings of the following parameters, consult icd- 200, sections 20.3.3.5.2.4, 20.3.3.5.1.8, and table 20-ix. on the simplest level, to get utc time from gps time, subtract ? t ls seconds. the other information contained in this packet indicates when the next leap second is scheduled to occur. table a-43 report utc parameters byte value type 0-7 a0 double 8-11 a1 single 12-13 ? t ls integer 14-17 t ot single 18-19 wn t integer 20-21 wn lsf integer 22-23 dn integer 24-25 ? t lsf integer www.datasheet.co.kr datasheet pdf - http://www..net/ a-52 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x54 report packet 54 bias and bias rate report the receiver sends this packet to provide the computed clock-only solution when the receiver is in the manual or automatic overdetermined clock mode or time only (1-sv) mode. the bias is the offset of the receiver internal time clock from gps time. bias is expressed as meters of apparent range from the satellites. it is used to correct the one pps output. bias rate is the frequency error of the receiver internal oscillator. it is expressed as apparent range rate. time-of-fix is in gps or utc time as selected by the i/o "timing" option in packet 0x35. i caution ? for accurate interpretation of the propagation delay, the precise constant for the speed of light must be used. the icd-200 value for the speed of light is 299,792,458 meters per second. 0x55 report packet 55 i/o option flags report this packet provides current i/o options in response to packet 35 request. the data format is the same as for packet 35. see packet 35 for details. table a-44 report packet 54 byte item type units 0-3 bias single meters 4-7 bias rate single meters/second 8-11 time of fix single seconds www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-53 a trimble standard interface protocol 0x56 report packet 56 velocity fix, east-north-up (enu) report if single precision east-north-up (enu) coordinates have been selected for the i/o "velocity" option (packet 35), the receiver sends this packet under the following conditions: (1) each time that a fix is computed if masked for output by packet 8e-4d; (2) in response to packet 37 (last known fix). the data format is shown in table a-45. the time-of-fix is in gps or utc time as selected by the i/o "timing" option. table a-45 0x56 ? velocity fix, east-north-up (enu) report byte item type units 0-3 east velocity single m/s; + for east, - for west 4-7 north velocity single m/s; + for north, - for south 8-11 up velocity single m/s; + for up, - for down 12-15 clock bias rate single m/s 16-19 time-of-fix single seconds www.datasheet.co.kr datasheet pdf - http://www..net/ a-54 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x57 report packet 57 information about last computed fix report this packet provides information concerning the time and origin of the previous position fix. the receiver sends this packet, among others, in response to packet 37. the data format is shown below. table a-46 report packet 57 byte item type/units value 0 source of information byte/- - - 0/none 1/regular fix 1 tracking mode byte/- - - 0/auto 1/time only 1-sv 2/2d clock hold 3/2d 4/3d 5/overdetermined clock 6/dgps reference 2-5 time of last fix single/seconds, gps time 6-7 week of last fix integer/weeks, gps time www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-55 a trimble standard interface protocol 0x58 report packet 58 satellite system data/acknowledge from receiver this packet provides gps data (almanac, ephemeris, etc.). the receiver sends this packet under the following conditions: (1) on request; (2) in response to packet 38 (acknowledges the loading of data). the data format is shown below. the binary almanac, health page, and utc data streams are similar to reports 40, 49, and 4f respectively, and those reports are preferred. to get ionosphere or ephemeris, this report must be used. table a-47 report packet 58 byte item type value meaning 0 operation byte 1 acknowledge 2data out 1 type of data byte 1 not used 2 almanac 3 health page, t_oa, wn_oa 4 ionosphere 5utc 6 ephemeris 2 sat prn # byte 0 data that is not satellite id- specific 1 to 32 satellite prn number 3 length (n) byte number of bytes of data to follow 4 to n+3 data n bytes www.datasheet.co.kr datasheet pdf - http://www..net/ a-56 acutime 2000 synchronization kit user guide trimble standard interface protocol a table a-48 report packet 58 ? almanac data report byte item type meaning 4 t_oa_raw byte (cf. icd-200, sec 20.3.3.5.1.2) 5 sv_health byte (cf. icd-200, sec 20.3.3.5.1.2) 6-9 e single (cf. icd-200, sec 20.3.3.5.1.2) 10-13 t_oa single (cf. icd-200, sec 20.3.3.5.1.2) 14-17 i_o single (cf. icd-200, sec 20.3.3.5.1.2) 18-21 omegadot single (cf. icd-200, sec 20.3.3.5.1.2) 22-25 sqrt_a single (cf. icd-200, sec 20.3.3.5.1.2) 26-29 omega_0 single (cf. icd-200, sec 20.3.3.5.1.2) 30-33 omega single (cf. icd-200, sec 20.3.3.5.1.2) 34-37 m_0 single (cf. icd-200, sec 20.3.3.5.1.2) 38-41 a_f0 single (cf. icd-200, sec 20.3.3.5.1.2) 42-45 a_f1 single (cf. icd-200, sec 20.3.3.5.1.2) 46-49 axis single (cf. icd-200, sec 20.3.3.5.1.2) 50-53 n single (cf. icd-200, sec 20.3.3.5.1.2) 54-57 omega_n single (cf. icd-200, sec 20.3.3.5.1.2) 58-61 odot_n single (cf. icd-200, sec 20.3.3.5.1.2) 62-65 t_zc single (cf. icd-200, sec 20.3.3.5.1.2) 66-67 weeknum integer (cf. icd-200, sec 20.3.3.5.1.2) 68-69 wn_oa integer (cf. icd-200, sec 20.3.3.5.1.2) note: all angles are in radians. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-57 a trimble standard interface protocol table a-49 report packet 58 ? almanac health data report byte item type meaning 4 week # for health byte (cf. icd-200, sec 20.3.3.5.1.3) 5-36 sv_health 32 bytes (cf. icd-200, sec 20.3.3.5.1.3) 37 t_oa for health byte (cf. icd-200, sec 20.3.3.5.1.3) 38 current t_oa byte units = seconds/2048 39-40 current week # integer table a-50 report packet 58 ? ionosphere data report byte item type meaning 4-11 --- --- compact storage of the following info 12-15 alpha_0 single (cf. icd-200, sec 20.3.3.5.1.9) 16-19 alpha_1 single (cf. icd-200, sec 20.3.3.5.1.9) 20-23 alpha_2 single (cf. icd-200, sec 20.3.3.5.1.9) 24-27 alpha_3 single (cf. icd-200, sec 20.3.3.5.1.9) 28-31 beta_0 single (cf. icd-200, sec 20.3.3.5.1.9) 32-35 beta_1 single (cf. icd-200, sec 20.3.3.5.1.9) 36-39 beta_2 single (cf. icd-200, sec 20.3.3.5.1.9) 40-43 beta_3 single (cf. icd-200, sec 20.3.3.5.1.9) www.datasheet.co.kr datasheet pdf - http://www..net/ a-58 acutime 2000 synchronization kit user guide trimble standard interface protocol a table a-51 report packet 58 ? utc data report byte item type meaning 4-16 --- --- compact storage of the following info 17-24 a_0 double (cf. icd-200, sec 20.3.3.5.1.8) 25-28 a_1 single (cf. icd-200, sec 20.3.3.5.1.8) 29-30 delta_t_ls integer (cf. icd-200, sec 20.3.3.5.1.8) 31-34 t_ot single (cf. icd-200, sec 20.3.3.5.1.8) 35-36 wn t integer (cf. icd-200, sec 20.3.3.5.1.8) 37-38 wn_lsf integer (cf. icd-200, sec 20.3.3.5.1.8) 39-40 dn integer (cf. icd-200, sec 20.3.3.5.1.8) 41-42 delta_t_lsf integer (cf. icd-200, sec 20.3.3.5.1.8) table a-52 report packet 58 ? ephemeris data report byte item type meaning 4 sv_number byte sv prn number 5-8 t_ephem single time of collection 9-10 weeknum integer (cf. icd-200, sec 20.3.3.3, table 20-i) 11 codel2 byte (cf. icd-200, sec 20.3.3.3, table 20-i) 12 l2pdata byte (cf. icd-200, sec 20.3.3.3, table 20-i) 13 svacc_raw byte (cf. icd-200, sec 20.3.3.3, table 20-i) 14 sv_health byte (cf. icd-200, sec 20.3.3.3, table 20-i) 15-16 iodc integer (cf. icd-200, sec 20.3.3.3, table 20-i) 17-20 t_gd single (cf. icd-200, sec 20.3.3.3, table 20-i) 21-24 t_oc single (cf. icd-200, sec 20.3.3.3, table 20-i) 25-28 a_f2 single (cf. icd-200, sec 20.3.3.3, table 20-i) 29-32 a_f1 single (cf. icd-200, sec 20.3.3.3, table 20-i) 33-36 a_f0 single (cf. icd-200, sec 20.3.3.3, table 20-i) 37-40 svacc single (cf. icd-200, sec 20.3.3.3, table 20-i) www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-59 a trimble standard interface protocol 41 iode byte (cf. icd-200, sec 20.3.3.4) 42 fit_interval byte (cf. icd-200, sec 20.3.3.4) 43-46 c_rs single (cf. icd-200, sec 20.3.3.4) 47-50 delta_n single (cf. icd-200, sec 20.3.3.4) 51-58 m_0 double (cf. icd-200, sec 20.3.3.4) 59-62 c_uc single (cf. icd-200, sec 20.3.3.4) 63-70 e double (cf. icd-200, sec 20.3.3.4) 71-74 c_us single (cf. icd-200, sec 20.3.3.4) 75-82 sqrt_a double (cf. icd-200, sec 20.3.3.4) 83-86 t_oe single (cf. icd-200, sec 20.3.3.4) 87-90 c_ic single (cf. icd-200, sec 20.3.3.4) 91-98 omega_0 double (cf. icd-200, sec 20.3.3.4) 99-102 c_is single (cf. icd-200, sec 20.3.3.4) 103-110 i_o double (cf. icd-200, sec 20.3.3.4) 111-114 c_rc single (cf. icd-200, sec 20.3.3.4) 115-122 omega double (cf. icd-200, sec 20.3.3.4) 123-126 omegadot single (cf. icd-200, sec 20.3.3.4) 127-130 idot single (cf. icd-200, sec 20.3.3.4) 131-138 axis double = (sqrt_a) 2 139-146 n double derived from delta_n 147-154 r1me2 double = sqrt(1.0-e 2 ) 155-162 omega_n double derived from omega_0, omegadot 163-170 odot_n double derived from omegadot note: all angles are in radians. table a-52 report packet 58 ? ephemeris data report (continued) byte item type meaning www.datasheet.co.kr datasheet pdf - http://www..net/ a-60 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x59 report packet 59 satellite attributes database report this packet is returned in response to packet 39 if operation mode 3 or 6 is used with packet 39. normally the gps receiver selects only healthy satellites (based on transmitted values in the ephemeris and almanac) which satisfy all mask values, for use in the position solution. packet 59 indicates whether each satellite is allowed or not allowed to be selected for use in the position solution, or whether each satellite?s health is to be heeded or ignored. the data format is shown below. * note ? when viewing the satellite disabled list, the satellites are not numbered but are in numerical order. the disabled satellites are signified by a 1 and enabled satellites are signified by a 0. table a-53 report packet 59 byte item type value meaning 0 operation byte 3 the remaining bytes tell whether receiver is allowed to select each satellite. 6 the remaining bytes tell whether the receiver heeds or ignores each satellite's health as a criterion for selection. 1 to 32 satellite # 32 bytes (1 byte per satellite) (depends on byte 0 value.) 0 enable satellite selection or heed satellite's health. default value. 1 disable satellite selection or ignore satellite's health. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-61 a trimble standard interface protocol 0x5a report packet 5a raw measurement data report this packet provides raw gps measurement data. if the i/o auxiliary option for "raw data" has been selected (packet 35), and it is masked for output by packet 8e-4d, the receiver outputs a packet 5a for each satellite being tracked, once per second. the receiver also sends this packet in response to packet 3a. the data format is shown below. * note ? report packet 5a provides the raw satellite signal measurement information used in computing a fix. the satellite prn (byte 0) number is a unique identification for each of the 32 gps satellites. table a-54 report packet 5a byte item type units 0 satellite prn number byte 1-4 reserved single 5-8 signal level single 9-12 code phase single 1/16th chip 13-16 doppler single hertz 17-24 time of measurement double seconds www.datasheet.co.kr datasheet pdf - http://www..net/ a-62 acutime 2000 synchronization kit user guide trimble standard interface protocol a signal level the signal level (byte 5) is a linear approximation of c/n0 which is stated in antenna amplitude measurement units (amus), a trimble devised unit. note ? snr (3) = 20log((signal counts/noise counts)*(bw/2)) where: signal counts = 64 * amu; noise counts = 90, and bw = 1000hz. the c/n0 is affected by five basic parameters: signal strength from the gps satellite receiver/antenna gain pre-amplifier noise figure receiver noise bandwidth accumulator sample rate and statistics the approximation is very accurate from 0 to 25 amus. codephase the codephase (byte 9) value is the average delay over the sample interval of the received c/a code and is measured with respect to the receiver's millisecond timing reference. thus, it includes all receiver, satellite, and propagation biases and errors. it is expressed in 1/16th of a c/a code chip. doppler the doppler (byte 13) value is apparent carrier frequency offset averaged over the sample interval. it is measured with respect to the nominal gps l1 frequency of 1575.42 mhz, referenced to the receiver's internal oscillator. thus, it includes all receiver and satellite clock frequency errors. it is expressed in hertz at the l1 carrier. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-63 a trimble standard interface protocol time of measurement the time of measurement (byte 17) is the center of the sample interval adjusted by adding the receiver-supplied codephase (modulo ms) to a user-determined integer number of ms between user and satellite. the receiver codephase resolution is 1/16th of a c/a code chip. this corresponds to: the integer millisecond portion of the pseudo-range must then be derived by utilizing the approximate user and satellite positions. rough user position (within a few hundred kilometers) must be known; the satellite position can be found in its almanac/ephemeris data. each ms integer corresponds to: the satellite time-of-transmission for a measurement can be reconstructed using the code phase, the time of measurement, and the user-determined integer number of milliseconds. 1/16 c/a code chip 977.517ns/16 61.0948 ns 61.0948 speed of light, m/s 18.3158 meters c/a code epoch speed of light = 1 ms speed of light m/s 300 km (approximate) 299.792458 km (precise) www.datasheet.co.kr datasheet pdf - http://www..net/ a-64 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x5b report packet 5b satellite ephemeris status report this packet is sent in response to packet 3b and optionally, when a new ephemeris (based on iode) is received. it contains information on the status of the ephemeris in the receiver for a given satellite. the structure of packet 5b is shown in the table below. sv prn number is from 1 to 32 representing the satellite prn number. time of collection is the gps time when this ephemeris data was collected from the satellite. health is the 6-bit ephemeris health. iode, toe, and fit interval flag are as described in icd-gps-200. sv accuracy (ura) is converted to meters from the 4-bit code as described in icd-gps-200. table a-55 report packet 5b byte item type units 0 satellite prn number byte 1-4 time of collection single seconds 5health byte 6iode byte 7-10 toe single seconds 11 fit interval flag byte 12-15 sv accuracy (ura) single meters www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-65 a trimble standard interface protocol 0x5c report packet 5c satellite tracking status report this packet provides tracking status data for a specified satellite. some of the information is very implementation-dependent and is provided mainly for diagnostic purposes. the receiver sends this packet in response to packet 3c hex. the data format is shown below. table a-56 report packet 5c byte/item type/units value/meaning byte 0 / satellite prn number byte/ number 1-32 byte 1 / channel and slot code byte bit position within byte 1: bits 7(msb)-3 (channel number beginning with 0) (msb) 0 0 0 0 0 channel 1: used by all receivers 0 0 0 0 1 channel 2: 8-channel receivers 0 0 0 1 0 channel 3: 8-channel receivers 0 0 0 1 1 channel 4: 8-channel receivers 0 0 1 0 0 channel 5: 8-channel receivers 0 0 1 0 1 channel 6: 8-channel receivers 0 0 1 1 0 channel 7: 8-channel receivers 0 0 1 1 1 channel 8: 8-channel receivers byte 2 / acquisition flag byte 0 never acquired 1 acquired 2 re-opened search byte 3 / ephemeris flag byte 0 flag not set ( 0 or 33) good ephemeris for this satellite (<4 hours old, good health) byte 4-7 / signal level single same as in packet 47 hex byte 8-11 / gps time of last measurement single/ seconds < 0 no measurements have been taken 0 center of the last measurement taken from this satellite www.datasheet.co.kr datasheet pdf - http://www..net/ a-66 acutime 2000 synchronization kit user guide trimble standard interface protocol a byte 12-15 / elevation single/ radians approximate elevation of this satellite above the horizon. updated about every 15 seconds. used for searching and computing measurement correction factors. byte 16-19 / azimuth single/ radians approximate azimuth from true north to this satellite. updated about every 15 seconds. used for computing measurement correction factors. byte 20 / old measurement flag byte n/a byte 21 / integer msec flag byte n/a byte 22 / bad data flag byte n/a byte 23 / data collection flag byte n/a table a-56 report packet 5c (continued) byte/item type/units value/meaning www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-67 a trimble standard interface protocol 0x5f-11 report packet 5f-11 eeprom segment status reports this report packet is sent in response to command packet 3f-11. it contains all the segments in the eeprom. the segment status is bitwise encoded with the status of each segment and is cleared to 0 after it is read. a zero in the bit field indicates that the segment contents are valid. a one in the bit field indicates that the segment contents were corrupt and had to be reverted to their factory default values. the manufacturing and production parameters (bits 0, 1) do not have factory default values. table a-57 report packet 5f-11 ? eeprom segment status report byte bit item type value meaning 0 subcode byte 0x11 1-2 0 1 2 3 4 5 6 7 8 9-10 11 12-15 segment status bit field u16 manufacturing parameters (8f-41) production parameters (8f-42) receiver configuration packet i/o control serial port configuration timing output configuration accurate position self-survey configuration nmea configuration (not used) utc information (not used) www.datasheet.co.kr datasheet pdf - http://www..net/ a-68 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x60 command packet 0x60 type 1 differential gps corrections this packet provides the receiver with differential corrections from rtcm sc-104 record types 1 and 9, in the tsip format. there is no response to this packet. if bit 6 is set, the corrections are as in rtcm type 9 records. the format for this packet is shown in table a-58. table a-58 report packet 0x60 data formats byte bit item type range units 0 - 1 modified z-count u16 0-5999 .6 sec 2 station health u8 -- 3 0 - 5 number of svs in packet bits 0-31 0 - 5 3 6 type 9 flag bit 0 1 type 1 type 9 3 7 version 2 flag bit 1 must be set www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-69 a trimble standard interface protocol the next 5 bytes are repeated as a group for each satellite. the sv prn and scale factor contains the sv prn in the lower 5 bits, and the scale factor in the upper 3 bits. range corrections are scaled by 0.02 meters times 2 raised to the scale factor power. range-rate corrections are scaled by 0.002 meters per second times 2 raised to the scale factor power. the format is shown in table a-59. table a-59 report packet 0x60 data formats for health and power byte bit item type value definition 4+ (n*5) 0-4 sv prn 0-31 "0" is sv 32 4+ (n*5) 5-7 scale factor 0 4 7 low scale factor (.02m, .002 m/s) high scale factor (.32m, .032 m/s) correction not usable 5+ (n*5) range correction u16 rtcm-104 7+ (n*5) range-rate correction u8 rtcm-104 8+ (n*5) iode u8 www.datasheet.co.kr datasheet pdf - http://www..net/ a-70 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x61 command packet 0x61 set differential gps corrections this tsip packet provides the delta differential corrections from rtcm-104 record type 2. there is no response to this packet. scale factors are version 1 unless the version 2 flag is set. the format for this packet is shown in table a-60. the units and scale factors are as defined by packet 0x 60. delta range correction rates are not entered. table a-60 command packet 0x61 data formats byte bit item type value definition 0 - 1 modified z-count u16 0-5999 .6 sec 2 0-6 number of svs 0-31 2 7 version 2 flag bit 1 must be set the next 3 bytes are repeated as a group for each satellite: 3+(n*2) 0-4 sv prn 0-31 "0" is sv 32 3+(n*2) 5-7 scale factor 0 4 7 low scale factor (.02m, .002 m/s) high scale factor (.32m, .032 m/s) correction not usable 4+(n*2) range correction u16 rtcm-104 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-71 a trimble standard interface protocol 0x6d report packet 6d all-in-view satellite selection report this packet provides a list of satellites used for position fixes by the gps receiver. the packet also provides the pdop, hdop, and vdop of that set and provides the current mode (automatic or manual, 3-d or 2-d). this packet has variable length equal to 16+nsvs (minimum 4), where "nsvs" is the number of satellites used in the solution. the gps receiver sends this packet in response to packet 24 or whenever a new satellite selection is attempted. the gps receiver attempts a new selection every 30 seconds and whenever satellite availability and tracking status change. the data format is shown below. table a-61 report packet 6d byte item type units 0modebytebit value meaning 0-2 0 auto 1 time only (1-sv) 2 2d clock hold 32d 43d 5 overdetermined clock 6 dgps reference 30auto 1 manual 4-7 - - nsvs 1-4 pdop single pdop 5-8 hdop single hdop 9-12 vdop single vdop 13-16 tdop single tdop (16+nsvs) sv prn byte www.datasheet.co.kr datasheet pdf - http://www..net/ a-72 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x7a command packet 7a set or request nmea interval and message mask the nmea mask determines whether or not a given nmea message will be output. if the bit for a message is set, the message will be sent every ?interval? seconds. to determine the nmea interval and message mask, use the values shown in table a-62. while fixes are being generated, the output order is: zda, gga, gll, vtg, gsa, gsv, rmc. table a-62 command packet 7a byte bit item type value definition 0 subcode u8 0 1 interval u8 1-255 fix interval in seconds 2 reserved u8 0 3 reserved u8 0 40 rmc bit 0 1 off on 4 1-7 reserved bit 0 50 gga bit 0 1 off on 51 gll bit 0 1 off on 52 vtg bit 0 1 off on 53 gsv bit 0 1 off on 54 gsa bit 0 1 off on 55 zda bit 0 1 off on 5 6-7 reserved bit 0 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-73 a trimble standard interface protocol 0x7b report packet 7b nmea message output this packet is sent in response to command packet 7a and has the same data format as packet 7a. 0x83 report packet 83 double-precision xyz position fix and bias information this packet provides current gps position fix in xyz ecef coordinates. if the i/o "position" option is set to "xyz ecef", the i/o double-precision option is selected (packet 35), and the packet is masked for output in packet 8e-4d, the receiver sends this packet each time a fix is computed. the data format is shown below. the time-of-fix is in gps time or utc, as selected by the i/o "timing" option in packet 0x35. at start-up, if the i/o double- precision option is selected, this packet is also sent with a negative time-of-fix to report the current stored position. packet 42 provides a single-precision version of this information. 0x84 report packet 84 double-precision lla position fix and bias information this packet provides current gps position fix in lla coordinates. if the i/o "position" option is set to "lla", the double-precision option table a-63 report packet 83 byte item type units 0-7 x double meters 8-15 y double meters 16-23 z double meters 24-31 clock bias double meters 32-35 time of fix single seconds www.datasheet.co.kr datasheet pdf - http://www..net/ a-74 acutime 2000 synchronization kit user guide trimble standard interface protocol a is selected (packet 35), and the packet is masked for output in packet 8e-4d, the receiver sends this packet each time a fix is computed. the data format is shown in the table below. the time-of-fix is in gps time or utc, as selected by the i/o "timing" option packet 35. at start-up, this packet is also sent with a negative time-of-fix to report the current stored position. packet 4a provides a single-precision version of this information. i caution ? when converting from radians to degrees, using an insufficiently precise approximation for the constant (pi) introduces significant and readily visible errors. the value of as specified in icd-gps-200 is 3.1415926535898. table a-64 report packet 84 byte item type units 0-7 latitude double radians; + for north, ? for south 8-15 longitude double radians; + for east, ? for west 16-23 altitude double meters 24-31 clock bias double meters 32-35 time of fix single seconds www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-75 a trimble standard interface protocol 0xbb command packet bb set primary receiver configuration tsip command packet bb contains the primary receiver configuration parameters. the acutime 2000 stores 3 independent sets of configuration parameters. these are designated as the "mobile", "survey" and "timing" configurations. the active configuration is determined by the survey state: when the survey state changes, the receiver automatically switches to the new configuration. only the active configuration can be programmed. to program configurations, switch the active configuration by changing to the appropriate survey state using packets 8e-a6 and 8e- a9, update the configuration (bb), and save settings (8e-26). there are restrictions to the dynamics code and operating dimension settings, which take effect when survey is enabled, ensuring that the receiver performs a valid survey and enters a timing mode afterwards. table a-65 survey state configurations survey state active configuration survey disabled mobile survey active survey survey complete timing www.datasheet.co.kr datasheet pdf - http://www..net/ a-76 acutime 2000 synchronization kit user guide trimble standard interface protocol a the following table shows valid settings for each configuration. send packet bb with subcode 0 as the only data byte, to query for the primary receiver configuration. the receiver will respond with report packet bb. the table below lists the individual fields within the bb packet. when sending this packet, enter 0xff or ?1.0 to leave any parameter unchanged. dynamics code the default is land mode, where the receiver assumes a moderate dynamic environment. in this case, the satellite search and re-acquisition routines are optimized for vehicle-type environments. in sea mode, the search and re-acquisition routines assume a low acceleration environment and the receiver reverts to the user-entered altitude in 2-d auto. in air mode, the search and re-acquisition routines are optimized for high acceleration conditions. elevation mask this is the minimum elevation angle for satellites to be used in a solution output by the receiver. satellites near the horizon are typically more difficult to track due to signal attenuation, and are also generally less accurate due to higher variability in the ionospheric and tropospheric corruption of the signal. when there are no obstructions, the receiver can generally track a satellite down to near the horizon. however, when this mask is set too low, the receiver may experience frequent constellation switching due to low elevation satellites being obscured. table a-66 vaild gps configuration settings survey state active configuration dynamics code operating dimension survey disabled mobile any any survey active survey land/sea/air 2d or 3d or auto survey complete timing stationary 1sv or over-determined www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-77 a trimble standard interface protocol frequent constellation switching is undesirable because position jumps may be experienced when selective availability is present and dgps is not available to remove these effects. the benefit of a low elevation mask is that more satellites are available for use in a solution and a better pdop may be yielded. the current default mask is set to 0.1745 radians (10) and provides a reasonable trade-off between the benefits and drawbacks. signal level mask this mask defines the minimum signal strength for a satellite used in a solution. there is some internal hysteresis on this threshold, which allows brief excursions below the threshold if lock is maintained and the signal was previously above the mask. this mask should be lowered only with caution since it is also used to minimize the effects of jammers and reflected signals on the receiver. users who require high accuracy can use a slightly higher mask of 6.0-8.0, since weaker measurements may be noisier and are often caused by reflected signals, which provide erroneous ranges. make sure that the elevation and snr masks are not set too low. the satellite geometry is sometimes improved considerably by selecting low-elevation satellites. these satellites are, however, subject to significant signal degradation by the greater ionospheric and tropospheric attenuation that occurs. they are also subject to more obscuration by the passing scenery when the receiver is in a moving vehicle. the code phase data from those satellites is more difficult to decode and therefore has more noise. * note ? a level of hysteresis in the signal level mask is allowed in the core operating software. the hysteresis allows the receiver to continue using satellite signals which fall slightly below the mask and prevents the receiver from incorporating a new signal until the signal level slightly exceeds the mask. this feature minimizes constellation changes caused by temporary fluctuations in signal levels. www.datasheet.co.kr datasheet pdf - http://www..net/ a-78 acutime 2000 synchronization kit user guide trimble standard interface protocol a pdop mask and switch the pdop mask is the maximum pdop limit for which any 2-d or 3-d position solution will be made. the pdop switch is the level at which the receiver stops attempting a 3-d solution, and tries for a 2-d solution when in automatic 2-d/3-d mode. the switch level has no effect on either manual mode. raising the pdop mask generally increases the fix density during obscuration, but the fixes with the higher pdop are less accurate (especially with selective availability present). lowering the mask improves the average accuracy at the risk of lowering the fix density. * note ? the receiver may require an initial position fix before switching to some modes. table a-67 command packet bb byte # item type value meaning default 0 subcode byte 0 primary receiver configuration block 1 operating dimension byte 0 1 3 4 5 6 7 automatic time only (1-sv) horizontal (2d) full position (3d) dgps reference 2d clock hold overdetermined clock full position 2dgps modebyte0 1 3 dgps off dgps only dgps auto dgps auto 3 dynamics code byte 1 2 3 4 land, <120 knots sea, <50 knots air, <800 knots static land www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-79 a trimble standard interface protocol 4 solution mode byte 1 overdetermined fix over- determined fix 5-8 elevation mask single 0- /2 lowest satellite elevation for fixes 0.1745 (10 deg.) 9-12 amu mask single minimum signal level for fixes 4.0 13-16 pdop mask single maximum pdop for fixes 8 17-20 pdop switch single selects 2d/3d mode 6 21 dgps age byte maximum time to use a dgps correction (seconds) 30 seconds 22 foliage mode byte 0 never never 23 reserved byte n/a n/a 24 reserved byte n/a n/a 25 measurement rate byte 0 1 hertz 1 hz 26 position fix rate byte 0 1 hertz 1 hz 27-42 reserved byte -1 reserved for future use table a-67 command packet bb (continued) byte # item type value meaning default www.datasheet.co.kr datasheet pdf - http://www..net/ a-80 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0xbb report packet bb report receiver configuration tsip report packet bb is used to report the receiver configuration options. for information about the data formats, see command packet bb. 0xbc command packet bc set port configuration parameters tsip command packet bc is used to set the communication parameters on port a and port b. the table below lists the individual fields within the bc packet. flow control is not supported. please refer to section a.2 "physical interface characteristics" for details on the capabilities of each port on the acutime 2000. table a-68 command packet bc byte # item type value meaning default 0 port number byte 0 1 0xff port b port a current port 1 input baud rate byte 0 1 2 3 4 5 6 7 8 9 none 110 baud 300 baud 600 baud 1200 baud 2400 baud 4800 baud 9600 baud 19200 baud 38400 baud 9600 2 output baud rate byte as above as above 9600 3 # data bits byte 2 3 7 bits 8 bits 8 bits www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-81 a trimble standard interface protocol 0xbc report packet bc request port configuration parameters tsip packet bc is used to request the communication parameters on port b. to query a port?s configuration parameters, send packet bc with only byte 0. table a-68, above, lists the individual fields within the bc report packet. 4parity byte0 1 2 none odd even odd 5 # stop bits byte 0 2 1 bit 2 bits 1 bit 6 reserved byte 0 none 7 input protocols byte 0 2 8 none tsip (port b only) rtcm (port a only) tsip (port b) none (port a) 8 output protocols byte 0 2 4 none tsip nmea tsip 9 reserved byte 0 none table a-68 command packet bc (continued) byte # item type value meaning default www.datasheet.co.kr datasheet pdf - http://www..net/ a-82 acutime 2000 synchronization kit user guide trimble standard interface protocol a a.15 custom oem packets several packets have been added to the core tsip protocol to provide additional capability for oem receivers. in oem packets 8e and their 8f responses, the first data byte is a subcode that indicates the superpacket type. for example, in packet 8e-14, 14 is the subcode that indicates the superpacket type. therefore, the id code for oem packets is 2 bytes long, followed by the data. a.16 tsip superpackets superpackets describes packets that reduce the i/o traffic with the receiver and facilitate interpretation to a modem or data acquisition device with limited programming facilities. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-83 a trimble standard interface protocol 0x8e-0b command packet 8e-0b request or configure super packet output the 8e-0b packet is identical in function to the 8e-ad packet. if the 8e-0b byte sequence is sent with no data, the receiver will return an 8f-0b packet on port b. the time reported by the 8f-0b packet on port b is always the beginning of the current second. www.datasheet.co.kr datasheet pdf - http://www..net/ a-84 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x8e-14 command packet 8e-14 set or request datum to request the current datum, send this packet with no data. the receiver will return packet 8f-14. this packet allows the user to change the default datum from wgs-84 to one of 180 selected datums or to a user-entered custom datum. the datum is a set of 5 parameters which describe an ellipsoid to convert the gps receiver's internal coordinate system of xyz ecef into latitude, longitude and altitude (lla). this will affect all calculations of lla in packets 4a and 84 and 8f-ac and 8f-0b. the receiver responds with packet 8f-14. the user may want to change the datum to match coordinates with some other system (usually a map). most maps are marked with the datum used and in the us the most popular datum for maps is nad-27. the user may also want to use a datum that is more optimized for the local shape of the earth in that area. however, these optimized datums are truly "local" and will provide very different results when used outside of the area for which they were intended. wgs-84 is an excellent general ellipsoid valid around the world. to change to one of the internally held datums the packet must contain exactly 2 bytes representing the integer value of the index of the datum desired. for a list of the datums and their indexes, see table a-99. table a-69 command packet 8e-14 byte # type value 0 superpacket id 0x14 1-2 integer datum index www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-85 a trimble standard interface protocol alternatively, the unit will accept a 40 byte input packet containing 5 double-precision floating point values representing the ellipse. the first 3 are dx, dy, and dz, which represent an offset in meters from the ecef origin for the ellipse. the fourth parameter is the semi-major axis of the ellipse (called the a-axis) and is also in meters. the fifth parameter is the eccentricity of the ellipse and is dimensionless. i caution ? the gps receiver does not perform an integrity check on the datum values. if unusual inputs are used, the output will be equally unusual. table a-70 command packet 8e-14 byte # type value units 0 superpacket id 0x14 1-8 double dx meters 9-16 double dy meters 17-24 double dz meters 25-32 double a-axis meters 33-40 double eccentricity squared none www.datasheet.co.kr datasheet pdf - http://www..net/ a-86 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x8e-20 command packet 8e-20 request last fix with extra information this packet requests packet 8f-20 or marks it for automatic output. if only the first byte (20) is sent, an 8f-20 report containing the last available fix will be sent immediately. if two bytes are sent, the packet is marked/unmarked for auto report according to the value of the second byte. * note ? auto-report requires that superpacket output is enabled. refer to command packet 35. this packet must also be enabled with packet 8e-4d. 0x8e-26 command packet 8e-26 write receiver configuration to eeprom this command packet causes the current configuration settings to be written to the eeprom. it also generates a report packet 8f-26. this packet contains only a single byte: the subpacket id. 0x8e-41 command packet 8e-41 manufacturing operating parameters this packet is used to request the manufacturing parameters stored in nonvolatile memory. the packet contains only a single byte, the subpacket id. the receiver returns packet 8f-41. table a-71 command packet 8e-20 byte # item type value 0 sub-packet id byte 0x20 1 mark for auto-report byte 0 = do not auto-report 1 = auto-report www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-87 a trimble standard interface protocol 0x8e-42 command packet 8e-42 production parameters this packet is used to request the production parameters stored in nonvolatile memory. this packet contains only a single byte, the subpacket id. the receiver returns packet 8f-42. 0x8e-45 command packet 8e-45 revert segments to default settings this command packet reverts the parameters stored in a specific eeprom segment (or all segments) to their factory default settings and reconfigures the acutime 2000 using those settings. the receiver returns packet 8f-45. table a-72 command packet 0x8e-45 byte item type value segment description 0 subcode byte 0x45 1segment number byte 2 3 4 5 6 7 8 11 0xfd 0xff receiver configuration packet i/o control serial port configuration timing output configuration accurate position self-survey configuration nmea configuration utc information segments 2 through 8 all segments www.datasheet.co.kr datasheet pdf - http://www..net/ a-88 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x8e-4a command packet 8e-4a set/request pps characteristics using this packet, you can query and control the receiver?s pps characteristics. the receiver responds to a query or control command with packet 8f-4a. the packet contains 16 bytes in the following order: to request 8f-4a, send a two-byte 8e-4a packet without any parameters. to update parameters, send the entire 16-byte message. table a-73 command packet 8e-4a byte # item type meaning 0 sub-packet id byte always 0x4a 1 pps driver switch byte 0 = off 1 = on (default) 2time base byte0: gps 1: utc (default) 3 pps polarity byte 0: positive (default) 1: negative 4-11 pps offset or cable delay double seconds (default = 0.0) 12-15 bias uncertainty threshold single meters (default = 300) www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-89 a trimble standard interface protocol the default setting for byte 3 is positive. bytes 4 to 11 define the pps cable delay offset. the default offset is 0, which corresponds to a 100- foot (30-meter) cable. these bytes allow the application to adjust the cable delay offset for longer or shorter cable lengths. use a cable delay of 1.25 ns/foot to adjust pps offset for cable lengths different than 100 feet. for a longer cable, a negative value should be used to advance the pps. the receiver estimates the bias uncertainty as part of a pps validity monitor. if the bias uncertainty exceeds the threshold, then the receiver disables the pps output. the default bias uncertainty threshold is 300 meters, but this parameter may be programmed by the application. the receiver limits the threshold to 3x10 8 meters. each time the application adjusts the packet 8e-4a settings, the new settings are stored in nonvolatile memory. 0x8e-4d command packet 8e-4d automatic packet output mask automatic output of packets on port b can be throttled using this command packet. the current mask can be requested by sending this packet with no data bytes except the subcode byte. the receiver returns packet 8f-4d. the automatic packet output mask can be set by sending this packet with 4 data bytes. this mask only disables automatic packet output. packets generated in response to tsip set or query commands will always be output by the receiver. table a-74 command packet 8e-4d byte # item type meaning 0 subcode byte id for this subpacket is always 0x4d 1-4 auto-output mask long 32-bit packet enable bitmap www.datasheet.co.kr datasheet pdf - http://www..net/ a-90 acutime 2000 synchronization kit user guide trimble standard interface protocol a the bits are numbered in descending order of receipt, starting with bit 31 as the msb of byte 1, down to bit 0 as the lsb of byte 4. a "0" in the bit position disables automatic output of the associated packets; a "1" in the bit position makes the associated packets available for automatic output. table a-75 describes the packets affected by each bit. table a-75 command packet 8e-4d - packets affected by bits bit # output packets default a2k when output meaning 0 (lsb) 40 0 after decode almanac data collected from satellite. 1 58, 5b 0 after decode ephemeris data collected from satellite. 2 4f 0 after decode utc data collected from satellite. 3 58 0 after decode ionospheric data collected from satellite. 4 48 0 after decode gps message. 5 49 0 after decode almanac health page collected from satellite. 6 reserved 1 reserved 7 reserved 1 reserved 8 41 1 new fix partial and full fix complete and packet output timer has expired. 9 reserved 1 reserved 10 reserved 1 reserved 11 (note 1) 6d, 46, 4b, 82 1 constellation change, new fix new satellite selection www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-91 a trimble standard interface protocol note 1: a 1 in the bit mask turns on the associated packets and a 0 turns off the output of the associated packets. 0x8e-4e command packet 8e-4e set pps output option this command packet sets the pps driver switch to one of the values listed in table a-76. the receiver returns packet 8f-4e. the current driver switch value can be requested by sending this packet with no data bytes except the subcode byte. 12-29 reserved 1 reserved 30 42, 43, 4a, 54, 56, 83, 84, 8f-20, 1new fix update kinetic and timing information. output must be enabled using i/o options. 31 5a 1 new fix raw measurement data output must be enabled using i/o options. table a-75 command packet 8e-4d - packets affected by bits bit # output packets default a2k when output meaning www.datasheet.co.kr datasheet pdf - http://www..net/ a-92 acutime 2000 synchronization kit user guide trimble standard interface protocol a driver switch values 3 and 4 only make sense in overdetermined timing mode. in any position fix mode the effective choices are always on or during fixes, which you get if you set the driver switch to 3 or 4. 0x8e-4f command packet 8e-4f for acutime 2000 only set pps width this command packet sets the pps width to a value in the range of 10 microseconds to 500 milliseconds. the receiver returns packet 8f-4f. the current pps width can be requested by sending this packet with no data bytes except the subcode byte. table a-76 command packet 0x8e-4e byte item type value meaning 0 subcode byte 0x4e 1pps driver switch byte 2 3 4 pps is always output pps is output when at least one satellite is tracking pps is output when at least three satellites are tracking table a-77 command packet 0x8e-4f byte item type value meaning 0 subcode byte 0x4f 1-8 pps width double seconds www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-93 a trimble standard interface protocol 0x8e-a5 command packet 8e-a5 set or request packet broadcast mask use command packet 8e-a5 to set the packet broadcast masks or to request the current mask settings. the receiver replies to requests with response packet 8f-a5. the broadcast mask is bitwise encoded to allow the user to turn on and off the automatic output (broadcast) of certain packets. for those broadcast packets that have multiple formats, the receiver will broadcast only one of the formats. if more than one of the formats is masked on for broadcast, then the format with the greatest precision of content will be sent and the rest will not. the coding for each bit in the mask follows: 0: turn off automatic output (broadcast) of this packet 1: turn on automatic output (broadcast) of this packet www.datasheet.co.kr datasheet pdf - http://www..net/ a-94 acutime 2000 synchronization kit user guide trimble standard interface protocol a table a-78 command packet 8e-a5 byte bit item type default description 0 subcode u8 0xa5 subcode 1-2 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0x8f-20 0x8f-ab 0x8f-ac 0x8f-0b 0x8f-0b 0x8f-0b 0x8f-0b 0x8f-ad 0x8f-ad 0x8f-ad 0x8f-ad bit field 1 0 0 0 0 1 0 0 0 1 0 0 1 1 0 0 enable 0x8f-20 output on port reserved reserved reserved reserved enable auto tsip outputs 0x8f-ab, primary timing info on all tsip output ports 0x8f-ac, supplemental timing info on all tsip output ports synchronous 0x8f-0b (1 hertz) on port a event output of 0x8f-0b on port a event output of 0x8f-0b on port b synchronous 0x8f-0b on port b synchronous 0x8f-ad (1 hertz) on port a event output of 0x8f-ad on port a event output of 0x8f-ad on port b synchronous 0x8f-ad on port b 3-4 0-15 bit field reserved (always 0) www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-95 a trimble standard interface protocol 0x8e-a6 command packet 8e-a6 issue self-survey command this command packet starts a self-survey. the receiver responds with report packet 8f-a6. this command has no effect when survey is disabled. 0x8e-a9 command packet 8e-a9 set self-survey parameters use command packet 8e-a9 to set the self-survey parameters or to request the current settings. the receiver replies with response packet 8f-a9. data fields: self-survey enable : use this field to enabled or disabled the self- survey mechanism. 0: disable the self-survey mechanism 1: enable the self-survey mechanism position save flag : use this field to tell the self-survey mechanism to automatically save (or to not save) the self-surveyed position at the end of the self-survey procedure. 0: do not automatically save the surveyed position when the self-survey is complete table a-79 command packet 8e-a6 byte item type value meaning 0 subcode byte 0xa6 1 self-survey command byte 0 restart self-survey www.datasheet.co.kr datasheet pdf - http://www..net/ a-96 acutime 2000 synchronization kit user guide trimble standard interface protocol a 1: automatically save the surveyed position when the self- survey is complete. self-survey length : use this field to specify the number of position fixes that are to be averaged together to form the self-surveyed position used for clock-only fixes. limits : 1 to (2 31 - 1) fixes. * note ? after disabling the self-survey, the survey in progress can be stopped by issuing a restart self-survey command (0x8e-a6). table a-80 command packet 8e-a9 data format < acutime 2000 synchronization kit user guide a-97 a trimble standard interface protocol 0x8e-ab command packet 8e-ab request primary timing packet this command packet may be used to request the primary timing packet 8f-ab. to receive report packet 8f-ab once per second use command 8e-a5 to enable the automatic output. the request type item determines how the receiver will reply to this command. request type 0: the most current primary timing values will be sent in report packet 8f-ab immediately. request type 1: the response is not sent immediately. instead report packet 8f-ab is sent within 20ms after the next pps output. this is the same time that the packet would be automatically sent if enabled. request type 2: same as type 1 except that both report packets 8f-ab and 0x8f-ac are sent after the next pps output. table a-81 command packet 8e-ab byte item type value meaning 0 subcode byte 0xab 1 request type byte 0 1 2 send 0x8f-ab immediately send 0x8f-ab on-time next second send 0x8f-ab and 0x8f-ac on- time next second www.datasheet.co.kr datasheet pdf - http://www..net/ a-98 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x8e-ac command packet 8e-ac request supplemental timing packet this command packet can be used to request the supplemental timing packet 8f-ac. to receive report packet 8f-ac once per second use command 8e-a5 to enable the automatic output. the request type item determines how the receiver will reply to this command. request type 0: the most current supplemental timing values will be sent in report packet 8f-ac immediately. request type 1: the response is not sent immediately. instead report packet 8f-ac is sent within 300ms after the next pps output. this is the same time that the packet would be automatically sent if enabled. request type 2: same as type 1 except that both report packets 8f-ab and 8f-ac are sent after the next pps output. table a-82 command packet 8e-ac byte item type value meaning 0 subcode byte 0xac 1 request type byte 0 1 2 send 0x8f-ac immediately send 0x8f-ac on-time next second send 0x8f-ab and 0x8f-ac on-time next second www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-99 a trimble standard interface protocol 0x8e-ad command packet 8e-ad (request 8f-ad) request or configure super packet output if the 8e-ad byte sequence is sent with no data, the receiver will generate an 8f-ad packet on port b. the time reported by the 8f-ad packet on port b is always the beginning of the current second. output of the 8f-ad primary utc timing packet on port a is configured by sending a 3 byte message 8e-ad n, where n ranges from 0 to 3, as defined below. the receiver returns the 8f-a5 super packet output mask. table a-83 command packet 8e-ad byte # item type value default meaning 0 subcode byte ad required super-packet id 1flagbyte0 1 2 3 3 disable packet output on port a output packet on port a only at pps output packet on port a only at event input output at both event input and pps www.datasheet.co.kr datasheet pdf - http://www..net/ a-100 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x8f-0b report packet 8f-0b comprehensive time the output of the packet is synchronized with the pps, and may also be generated in response to external events. report packet 8f-0b provides easy identification of each timing pulse and contains all the information required for most timing and synchronization applications. output of this packet can be disabled and configured using the 8e-a5 packet on port b. if output of the 8f-ad packet is also enabled, the 8f-0b packet will always be output after the 8f-ad packet. the packet contains 74 bytes in the following order: table a-84 report packet 8f-0b byte # item type meaning 0 subpacket id byte subcode 0x0b 1-2 event count integer external event counter. zero for pps. 3-10 utc/gps tow double utc/gps time of week (seconds) 11 date byte date of event or pps 12 month byte month of event or pps 13-14 year integer year of event or pps 15 receiver mode byte receiver operating dimensions 0 horizontal (2d) 1 full position (3d) (survey) 2 single satellite (0d) 3 automatic (2d/3d) 4 dgps reference 4 clock hold (2d) 6 overdetermined clock (default) 16-17 utc offset integer utc offset value (seconds) 18-25 oscillator bias double oscillator bias (meters) 26-33 oscillator drift rate double oscillator drift (meters/second) 34-37 oscillator bias uncertainty single oscillator bias uncertainty (meters) www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-101 a trimble standard interface protocol bytes 66 through 73 identify the tracking and usable satellites. a tracked satellite is distinguished from a usable satellite by a negative sign ( ? ) appended to its prn number. in this superpacket, time is referenced to utc to correspond to the default pps timebase. to configure the receiver to output time relative to gps, the pps must be characterized accordingly. command packet 8e-4a enables the pps to be re-defined at run-time and stores the new settings in nonvolatile memory. * note ? leap seconds can not be predicted in advance using only the 8f-0b packet. a leap second can be identified by observing that the date does not increment after 86400 seconds have elapsed in the current day. the date rollover is delayed for the duration of the leap second, and the day/month/year count reported does not increment to the next day until the beginning of the second following the leap event. decoding of the 8f-ad packet provides complete leap status information. the utc offset is incremented at the beginning of the first second following the leap second. 38-41 oscillator drift uncertainty single oscillator bias rate uncertainty (meters/second) 42-49 latitude double latitude in radians 50-57 longitude double longitude in radians 58-65 altitude double altitude according to current datum, meters 66-73 satellite id 8 bytes identification numbers of tracking and usable satellites table a-84 report packet 8f-0b (continued) byte # item type meaning www.datasheet.co.kr datasheet pdf - http://www..net/ a-102 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x8f-14 report packet 8f-14 current datum values this packet contains 43 data bytes with the values for the datum currently in use and is sent in response to packet 8e-14. if a built-in datum is being used, both the datum index and the five double-precision values for that index are returned. if the receiver is operating on a custom user-entered datum, the datum index is set to ? 1 and the five values are displayed. these five values describe an ellipsoid to convert ecef xyz coordinate system into lla. * note ? a complete list of datums is provided at the end of this appendix. table a-85 report packet 8f-14 byte # type value units 0 super packet id 14 1-2 integer datum index (-1 for custom) 3-10 double dx meters 11-18 double dy meters 19-26 double dz meters 27-34 double a-axis meters 35-42 double eccentricity squared none www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-103 a trimble standard interface protocol 0x8f-20 report packet 8f-20 last fix with extra information (binary fixed point) this packet provides information concerning the time and origin of the previous position fix. this is the last-calculated fix; it could be quite old. the receiver sends this packet in response to packet 8e-20; it also can replace automatic reporting of position and velocity packets. automatic output of 8f-20 must also be enabled by setting bit 5 of byte 0 in command packet 0x35 and bit 0 of bytes 1-2 in command packet 0x8e-a5. the data format is shown in the table below. table a-86 report packet 8f-20 byte # item/type meaning 0 subpacket id / byte id for this subpacket (always 0x20) 1 key byte/byte reserved for trimble dgps postprocessing 2-3 east velocity / integer units 0.005 m/s or 0.020 m/s (see byte 24). overflow = 0 x 8000 4-5 north velocity / integer units 0.005 m/s or 0.020 m/s (see byte 24). overflow = 0 x 8000 6-7 up velocity /integer units 0.005 m/s or 0.020 m/s (see byte 24). overflow = 0 x 8000 8-11 time of week / unsigned long gps time in milliseconds 12-15 latitude / long integer latitude, units = 2 -31 semicircle, according to current datum. range = -2 30 to 2 32 16-19 longitude / unsigned long longitude east of meridian, units = 2 -31 semicircle, according to current datum. range = 0 to 2 32 20-23 altitude / long integer altitude above ellipsoid, mm, according current datum. 24 velocity scaling when bit 0 is set to 1, velocities in bytes 2-7 have been scaled by 4. www.datasheet.co.kr datasheet pdf - http://www..net/ a-104 acutime 2000 synchronization kit user guide trimble standard interface protocol a 25 reserved 0 26 datum datum index + 1 27 fix type / byte type of fix. this is a set of flags. 0 (lsb) 0: fix was available 1: no fix available 1 0: fix is autonomous 1: fix was corrected with rtcm 2 0: 3d fix 1: 2d fix 3 0: 2d fix used last-circulated altitude 1: 2d fix used entered altitude 4 0: unfiltered 1: position or altitude filter on 5-7 unused (always 0) 28 num svs/byte number of satellites used for fix. will be zero if no fix was available. 29 utc offset / byte number of leap seconds between utc time and gps time. 30-31 week/integer gps time of fix (weeks) 32-47 fix svs repeated groups of 2 bytes, one for each satellite. the bytes are 0 if group n/a. the following table describes the contents of each group. 48-55 iono param / 8 bytes the broadcast ionospheric parameters. table a-87 report packet 8f-20 bytes 32-47 item/type meaning 0 prnx/byte satellite number and iodc - iode. prn = the lower six bits of prnx. iodc = (prnx/64) 256 + iode 1iode/byte table a-86 report packet 8f-20 (continued) byte # item/type meaning www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-105 a trimble standard interface protocol 0x8f-26 report packet 0x8f-26 response to save eeprom segments this report packet is output after the command packet 8e-26 has been executed. table a-88 report packet 0x8f-26 byte item type value meaning 0 subcode byte 0x26 1-4 reserved ulong 0x00 www.datasheet.co.kr datasheet pdf - http://www..net/ a-106 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x8f-41 report packet 8f-41 manufacturing parameters this packet provides information on the manufacturing parameters stored in nonvolatile memory in response to command packet 8e-41. table a-89 report packet 8f-41 byte # item type meaning 0 subcode byte id for this subpacket is always 0x41 1-2 board serial number prefix integer 3-6 board serial number ulong 7 year of build byte 8 month of build byte 9 day of build byte 10 hour of build byte 11-14 oscillator offset single 15-16 test code identification number integer www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-107 a trimble standard interface protocol 0x8f-42 report packet 8f-42 production parameters this packet provides information on the production parameters stored in nonvolatile memory in response to command packet 8e-42. 0x8f-45 report packet 8f-45 this report packet is output after the command packet 8e-45 has been executed. see the corresponding command packet for information about the data formats. table a-90 report packet 8f-42 byte # item type meaning 0 subcode byte id for this subpacket is always 0x42 1 production options prefix byte 2 production number extension byte 3-4 case serial number prefix integer 5-8 case serial number ulong 9-12 production number ulong 13-14 reserved integer 15-16 machine identification number integer 17-18 reserved integer www.datasheet.co.kr datasheet pdf - http://www..net/ a-108 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x8f-4a report packet 8f-4a pps characteristics this packet reports the receiver?s pps characteristics. this packet is sent in response to a query or control command with packet 8e-4a. the packet contains 16 bytes in the following order: table a-91 report packet 8f-4a byte # item type units 0 subpacket id byte always 0x4a 1 pps driver switch byte 0: off 1: on 2time base byte0: gps 1: utc (default) 3 pps polarity byte 0: positive (default) 1: negative 4-11 pps offset or cable delay double seconds 12-15 bias uncertainty threshold single meters www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-109 a trimble standard interface protocol 0x8f-4d report packet 8f-4d automatic packet output mask this packet provides information on the automatic packets that may be output by the receiver. sent in response to 8e-4d query or set. a "0" in the bit position means that automatic output of the associated packets is disabled; a "1" in the bit positions means that the associated packets can be automatically output. the following table describes the meaning and packets output by each set bit. table a-92 report packet 8f-4d byte # item type meaning 0 subcode byte id for this sub-packet is always 0x4d 1-4 bit mask ulong bits in the mask enable output packets table a-93 report packet 8f-4d bit # output packets when output meaning 0(lsb) 40 alm after decode almanac data collected from satellite 1 58, 5b after decode ephemeris data collected from satellite. 2 4f after decode utc data collected from satellite 3 58 after decode ionospheric data collected from satellite 4 48 after decode gps message. 5 49 after decode almanac health page collected from satellite. 6 reserved 7 reserved 8 41 new fix partial and full fix complete and packet output timer has expired. www.datasheet.co.kr datasheet pdf - http://www..net/ a-110 acutime 2000 synchronization kit user guide trimble standard interface protocol a note 1: a 1 in the bit mask indicates that output for the associated packets is on; a 0 indicates that the output is turned off. 0x8f-4e report packet 0x8f-4e this report packet is output after the command packet 8e-4e has been executed. see the corresponding command packet for information about the data formats. 0x8f-a5 report packet 8f-a5 this report packet is output after the command packet 8e-a5 has been executed and is identical in structure to packet 8e-a5. see the corresponding command packet for information about the data formats. 9 reserved 10 reserved 11 6d, 82 constellation change new satellite selection 12 reserved 13-29 reserved 30 4a, 8f-20, 42, 43, 54, 56, 82, 83, 84 new fix update dynamic and timing information. output must be enabled with i/o options. 31 (note 1) 5a new fix output must be enabled with i/o options. table a-93 report packet 8f-4d (continued) bit # output packets when output meaning www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-111 a trimble standard interface protocol 0x8f-a6 report packet 8f-a6 this report packet is output after the command packet 8e-a6 has been executed and is identical in structure to packet 8e-a6. see the corresponding command packet for information about the data formats. 0x8f-a9 report packet 0x8f-a9 this report packet is output after the command packet 8e-a9 has been executed and is identical in structure to packet 8e-a9. see the corresponding command packet for information about the data formats. 0x8f-ab report packet 8f-ab this automatic report packet provides time information once per second if enabled with command packet 8e-a5. gps week number, gps time-of-week (tow), utc integer offset, time flags, date and time-of-day (tod) information is provided. this packet can be requested with packet 8e-ab. this packet will begin transmission within 30 ms after the pps pulse to which it refers. data fields: time of week : this field represents the number of seconds since sunday at 00:00:00 gps time for the current gps week. time of week is often abbreviated as tow. week number : this field represents the current gps week number. gps week number 0 started on january 6, 1980. unfortunately, the gps system has allotted only 10-bits of information to carry the gps week number and therefore it rolls-over to 0 in just 1024 weeks (19.6 years), and there is no mechanism built into gps to tell the user to which 1024 week epoch the week number refers. the first week www.datasheet.co.kr datasheet pdf - http://www..net/ a-112 acutime 2000 synchronization kit user guide trimble standard interface protocol a number roll-over occurred as august 21, 1999 (gps) transitioned to august 22, 1999 (gps). the receiver adjusts for this week rollover by adding 1024 to any week number reported by gps that is less than week number 1023, which began on december 14, 1997. with this technique, the receiver will provide an accurate translation of gps week number and tow to time and date until july 30, 2017. utc offset : this field represents the current integer leap second offset between gps and utc according to the relationship: time (utc) = time (gps) - utc offset. the utc offset information is reported to receiver by the gps system and can take up to 12.5 minutes to obtain. before the receiver has received utc information from the gps system, it is only capable of representing time in the gps time scale, and the utc offset will be shown as 0. timing flags : this field is bitwise encoded to provide information about the timing outputs. unused bits should be ignored. bit 0 : when 0, the date and time fields broadcast in packet 0x8f-ab are in the gps time scale. when 1, these fields are in the utc time scale and are adjusted for leap seconds. bit 2 : when 0, time has been set from gps. when 1, time has not yet been set from gps. bit 3 : when 0, utc offset information has been received. when 1, utc offset information is not yet known. time of day : the time of day is sent in hours-minutes-seconds format and varies from 00:00:00 to 23:59:59, except when time is in utc and a leap second insertion occurs. in this case the time will transition from 23:59:59 to 23:59:60 to 00:00:00. date : the date is sent in day-month-year format. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-113 a trimble standard interface protocol table a-94 report packet 0x8f-ab byte bit item type value meaning 0 subcode byte 0xab 1-4 time of week ulong gps seconds of week 5-6 week number uinteger gps week number (see above) 7-8 utc offset integer utc offset (seconds) 90 1 2 3 timing flag bit field 0 1 0 1 0 1 0 1 gps time utc time reserved reserved time is set time is not set have utc info no utc info 10 seconds byte 0-59 (60 for utc leap second event) 11 minutes byte 0-59 minutes of hour 12 hours byte 0-23 hour of day 13 day of month byte 1-31 day of month 14 month byte 1-12 month of year 15-16 year uinteger four digits of year (e.g. 1999) www.datasheet.co.kr datasheet pdf - http://www..net/ a-114 acutime 2000 synchronization kit user guide trimble standard interface protocol a 0x8f-ac report packet 8f-ac this report packet provides supplemental timing information once per second if enabled with command packet 8e-a5. information regarding position, unit status and health, and the operational state of the unit is provided. this packet can be requested with command packet 8e-ac. when enabled, this packet is transmitted once per second shortly after report packet 8f-ab. the position sent in report packet 8f-ac depends on the receiver operating mode and on self-survey activity. when a self-survey is in progress, the position sent is the running average of all of the position fixes collected so far. when the self-survey ends or whenever the receiver is using a time-only operating mode, then the position sent is the position the receiver is using to perform time-only fixes. when the self-survey is disabled or otherwise inactive and the receiver is using a position fix operating mode, then the position sent is the position fix computed on the last second. data fields: receiver mode : this field shows the fix mode that the gps receiver is currently configured for. see packet 0xbb for a description of all available receiver modes. self-survey progress : when a self-survey procedure is in progress, this field shows the progress of the survey as a percentage of fixes collected so far. the self-survey will be complete when the self- survey progress reaches 100 percent. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-115 a trimble standard interface protocol minor alarms : this field is bitwise encoded with several minor alarm indicators. a minor alarm indicates a condition that the user should be alerted to, but does not indicate an immediate (or necessarily any) impairment of functionality. for each bit, a value of 0 means that the condition is not indicated. bits not described below should be ignored. bit 3 when 1, indicates that no satellites are yet usable. in order for a satellite to be usable, it must be tracked long enough to obtain ephemeris and health data. bit 5 when 1, indicates that a self-survey procedure is in progress. bit 6 when 1, indicates that there is no accurate position stored in eeprom. bit 7 when 1, indicates that the gps has alerted the gps receiver that a leap second transition is pending. bit 8 when 1, indicates that the gps receiver is operating in one of its test modes. bit 9 when 1, indicates that the accuracy of the position being used for a time-only fix is questionable. while operating in the overdetermined clock mode (which is most of the time) with at least 2 satellites available, the receiver can detect position inaccuracies as small as 1/2 to 1 mile. if this bit is set, it is likely that the receiver is using a stored position but has been moved to a new site. the stored position should be cleared (packet 0x8e-45) and a new position should be established either by user input (packet 0x31 or 0x32) or by self-survey (packet 0x8e-a6). bit 10 when 1, indicates that one or more eeprom segments where found to be corrupt at reset and had to be set to their factory default settings. use packet 0x3f-11 to retrieve details about which segments where corrupt and to clear this bit. the gps receiver will send packet 0x5f-11 with the segment status. only bits 2-12 of the segment status are used to set this alarm bit. bit 11 when 1, indicates that the almanac is not current or complete. www.datasheet.co.kr datasheet pdf - http://www..net/ a-116 acutime 2000 synchronization kit user guide trimble standard interface protocol a gps decoding status : this field indicates the decoding status of the gps receiver. local clock offset : this field carries the offset of the local clock relative to utc or gps as reported by the gps receiver in nanoseconds. positive values indicate that the receiver?s local clock is late relative to gps or utc. also known as bias. oscillator offset : this field carries the frequency offset of the local clock relative to utc or gps as reported by the gps receiver in ppb (parts-per-billion). positive values indicate that the receiver?s local clock is running slow relative to gps or utc. also known as bias rate. latitude : this field carries the latitude of the position being shown. the units are in radians and vary from - /2 to + /2. negative values represent southern latitudes. positive values represent northern latitudes. longitude : this field carries the longitude of the position being shown. the units are in radians and vary from - to + . negative values represent western longitudes. positive values represent eastern longitudes. altitude : this field carries the altitude of the position being shown. the units are in meters according to the current datum. pps quantization error : this field identifies the pps quantization error in nanoseconds. pps output status : this field identifies the status of the pps output. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-117 a trimble standard interface protocol the table below identifies the fields associated with packet 8f-ac. table a-95 report packet 8f-ac byte bit item type value meaning 0 subcode byte 0xac 1 receiver mode byte 0 1 3 4 5 6 7 automatic (2d/3d) single satellite (time) horizontal (2d) full position (3d) dgps reference clock hold (2d) overdetermined clock 2 reserved 3 self-survey progress byte 0-100 percent completed 4-9 reserved 10-11 minor alarms uinteger bit field bit 1: antenna open bit 2: antenna shorted bit 3: not tracking satellites bit 5: survey-in progress bit 6: no stored position bit 7: leap second pending bit 8: in test mode bit 10: eeprom segments status bit 11: almanac status 12 gps decoding status byte 0 1 3 8 9 0x0a 0x0b 0x0c 0x10 doing fixes do not have gps time pdop is too high no usable satellites only 1 usable satellite only 2 usable satellites only 3 usable satellites the chosen satellite is unusable traim rejected the fix 13-15 reserved www.datasheet.co.kr datasheet pdf - http://www..net/ a-118 acutime 2000 synchronization kit user guide trimble standard interface protocol a 16-19 bias single estimate of utc/gps offset (ns) of local clock 20-23 bias rate single estimate of utc/gps offset (ppb) of local clock 24-35 reserved 36-43 latitude double radians 44-51 longitude double radians 52-59 altitude double meters 60-63 pps quantization error single pps quantization error (ns) 64 pps output status u8 0: pps not generated 1: pps was generated 65-67 reserved table a-95 report packet 8f-ac (continued) byte bit item type value meaning www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-119 a trimble standard interface protocol 0x8f-ad report packet 8f-ad primary utc time the output of the 8f-ad packet is synchronized with the pps, and may also be generated in response to external events. this packet provides accurate time and date information for time stamping and time transfer. the leap flag provides complete utc event information, allowing implementation of sophisticated distributed systems intended to operate synchronously with utc time. this packet is always output first in a possible sequence of up to 4 synchronous packets. output of this packet can be disabled and configured using the 8e-ad packet . table a-96 report packet 8f-ad byte # item type meaning 0 subpacket id byte subcode 0xad 1-2 event count integer external event counter. zero for pps. 3-10 fractional second double time elapsed in current second (seconds) 11 hour byte utc hour 12 minute byte utc minute 13 second byte second (0-59; 60 = leap) 14 day byte date (1-31) 15 month byte month (1-12) 16-17 year integer year (4 digit) 18 receiver status byte tracking status (see definition below) 19 utc flags byte leap second flags (see definition below) 20 reserved byte contains 0xff 21 reserved byte contains 0xff www.datasheet.co.kr datasheet pdf - http://www..net/ a-120 acutime 2000 synchronization kit user guide trimble standard interface protocol a the tracking status flag allows precise monitoring of receiver tracking status and allows a host system to determine whether the time output by the receiver is valid. after self-survey has completed, the receiver only needs to track one satellite to maintain precise synchronization with utc. table a-97 tracking status flag definitions flag value status meaning 0 doing_fixes receiver is navigating. 1 good_1sv receiver is timing using one satellite 2 appx_1sv approximate time 3need_time start-up 4 need_initalization start-up 5 pdop_high dilution of precision too high 6 bad_1sv satellite is unusable 7 0svs no satellites usable 8 1sv only 1 satellite usable 9 2svs only 2 satellites usable 10 3svs only 3 satellites usable 11 no_integrity invalid solution 12 dcorr_gen differential corrections 13 overdet_clk overdetermined fixes www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-121 a trimble standard interface protocol leap second flag leap seconds are inserted into the utc timescale to counter the effect of gradual slowing of the earth?s rotation due to friction. the 8f-ad packet provides extensive utc leap second information to the user application. the leap scheduled bit is set by the receiver, when the leap second has been scheduled by the gps control segment. the control segment may schedule the leap second several weeks before the leap second takes place. the leap pending bit indicates that the leap second will be inserted at the end of the current day. the gps leap warning bit is set while gps is operating in the leap exception mode specified in icd-200. the leap in progress bit is set to 1 at the beginning of the leap second, and cleared at the beginning of the second following the leap event. the date rollover is delayed by one second on the day the leap second is inserted. the date will not increment until the beginning of the first second following the leap second. table a-98 leap second flag definitions bit # name meaning if set to 1 0 utc flag utc time is available 1-3 reserved n/a 4 leap scheduled gps almanac?s leap second date is not in the past. 5 leap pending 24-hour warning. cleared before leap second. 6 gps leap warning set +/- 6 hours before/after leap event. 7 leap in progress leap second is now being inserted. www.datasheet.co.kr datasheet pdf - http://www..net/ a-122 acutime 2000 synchronization kit user guide trimble standard interface protocol a a.17 datums the table on the following pages lists datums. table a-99 datums index dx dy dz a-axis eccentricity description 0 0 0 0 6378137.000 0.00669437999014 /*wgs-84*/ 1 -128 481 664 637797.155 0.00667437311265 /*tokyo from old j6 values*/ 2 -8 160 176 6378206.400 0.0067865799761 /*nad-27*/ 3 -9 151 185 6378206.400 0.00676865799761 /*alaska/canada*/ 4 -87 -98 -121 6378388.000 0.00672267002233 /*european*/ 5 -133 -48 148 6378160.000 0.00669454185459 /*australian*/ 6 0 0 4 6378135.000 0.00669431777827 /*wgs-72*/ 7 0 0 0 6378137.000 0.00669438002290 /*nad-83*/ 8 0 0 0 6378137.000 0.00669437999014 /*nad-02*/ 9 0 0 0 6378137.000 0.00669437999014 /*mexican*/ 10 0 0 0 6378137.000 0.00669437999014 /*hawaiian*/ 11 0 0 0 6378137.000 0.00669437999014 /*astronomic*/ 12 0 0 0 6378137.000 0.00669437999014 /*u s navy*/ 13 -87 -98 -121 6378388.000 0.00672267002233 /*european*/ 14 -134 -48 149 6378160.000 0.00669454185459 /*australian 1984*/ 15 -166 -15 204 6378249.145 0.00680351128285 /*adindan-mean*/ 16 -165 -11 206 6378249.145 0.00680351128285 /*adindan-ethiopia*/ 17 -123 -20 220 6378249.145 0.00680351128285 /*adindan-mali*/ 18 -128 -18 224 6378249.145 0.00680351128285 /*adindan-senegal*/ 19 -161 -14 205 6378249.145 0.00680351128285 /*adindan-sudan*/ 20 -43 -163 45 6378245.000 0.00669342162297 /*afgooye-somalia*/ 21 -150 -250 -1 6378388.000 0.00672267002233 /*ain el abd- bahrain*/ 22 -491 -22 435 6378160.000 0.00669454185459 /*anna 1 astr 1965*/ 23 -143 -90 -294 6378249.145 0.00680351128285 /*arc 1950-mean*/ 24 -138 -105 -289 6378249.145 0.00680351128285 /*arc 1950- botswana*/ www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-123 a trimble standard interface protocol 25 -125 -108 -295 6378249.145 0.00680351128285 /*arc 1950-lesotho*/ 26 -161 -73 -317 6378249.145 0.00680351128285 /*arc 1950-malawi*/ 27 -134 -105 -295 6378249.145 0.00680351128285 /*arc 1950- swaziland*/ 28 -169 -19 -278 6378249.145 0.00680351128285 /*arc 1950-zaire*/ 29 -147 -74 -283 6378249.145 0.00680351128285 /*arc 1950-zambia*/ 30 -142 -96 -293 6378249.145 0.00680351128285 /*arc 1950- zimbabwe*/ 31 -160 -6 -302 6378249.145 0.00680351128285 /*arc 1960-mean*/ 32 -160 -6 -302 6378249.145 0.00680351128285 /*arc 1960-kenya*/ 33 -160 -6 -302 6378249.145 0.00680351128285 /*arc 1960- tanzania*/ 34 -205 107 53 6378388.000 0.00672267002233 /*ascension isl 1958*/ 35 145 75 272 6378388.000 0.00672267002233 /*astro beacon e 1945*/ 36 114 -116 -333 6378388.000 0.00672267002233 /*astro b4 sorol atoll*/ 37 -320 550 -494 6378388.000 0.00672267002233 /*astro dos 71/4*/ 38 124 -234 -25 6378388.000 0.00672267002233 /*astro station 1952*/ 39 -133 -48 148 6378160.000 0.00669454185459 /*australian geo 1966*/ 40 -127 -769 472 6378388.000 0.00672267002233 /*bellevue (ign)*/ 41 -73 213 296 6378206.400 0.00676865799761 /*bermuda 1957*/ 42 307 304 -318 6378388.000 0.00672267002233 /*bogota observatory*/ 43 -148 136 90 6378388.000 0.00672267002233 /*compo inchauspe*/ 44 298 -304 -375 6378388.000 0.00672267002233 /*canton island 1966*/ 45 -136 -108 -292 6378249.145 0.00680351128285 /*cape*/ table a-99 datums (continued) index dx dy dz a-axis eccentricity description www.datasheet.co.kr datasheet pdf - http://www..net/ a-124 acutime 2000 synchronization kit user guide trimble standard interface protocol a 46 -2 151 181 6378206.400 0.00676865799761 /*cape canaveral mean*/ 47 -263 6 431 6378249.145 0.00680351128285 /*carthage*/ 48 175 -38 113 6378388.000 0.00672267002233 /*chatham 1971*/ 49 -134 229 -29 6378388.000 0.00672267002233 /*chua astro*/ 50 -206 172 -6 6378388.000 0.00672267002233 /*corrego alegre*/ 51 -377 681 -50 6377397.155 0.00667437223180 /*djakarta (batavia)*/ 52 230 -199 -752 6378388.000 0.00672267002233 /*dos 1968*/ 53 211 147 111 6378388.000 0.00672267002233 /*easter island 1967*/ 54 -87 -98 -121 6378388.000 0.00672267002233 /*euro 1950-mean*/ 55 -104 -101 -140 6378388.000 0.00672267002233 /*euro 1950-cyprus*/ 56 -130 -117 -151 6378388.000 0.00672267002233 /*euro 1950-egypt*/ 57 -86 -96 -120 6378388.000 0.00672267002233 /*euro 1950-eng/ scot*/ 58 -86 -96 -120 6378388.000 0.00672267002233 /*euro 1950-eng/ire*/ 59 -84 -95 -130 6378388.000 0.00672267002233 /*euro 1950- greece*/ 60 -117 -132 -164 6378388.000 0.00672267002233 /*euro 1950-iran*/ 61 -97 -103 -120 6378388.000 0.00672267002233 /*euro 1950- sardinia*/ 62 -97 -88 -135 6378388.000 0.00672267002233 /*euro 1950-sicily*/ 63 -87 -95 -120 6378388.000 0.00672267002233 /*euro 1950- norway*/ 64 -87 -107 -120 6378388.000 0.00672267002233 /*euro 1950-port/ spain*/ 65 -86 -98 -119 6378388.000 0.00672267002233 /*european 1979*/ 66 -133 -321 50 6378388.000 0.00672267002233 /*gandajika base*/ 67 84 -22 209 6378388.000 0.00672267002233 /*geodetic datum 1949*/ 68 -100 -248 259 6378206.400 0.00676865799761 /*guam 1963*/ 69 252 -209 -751 6378388.000 0.00672267002233 /*gux 1 astro*/ table a-99 datums (continued) index dx dy dz a-axis eccentricity description www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-125 a trimble standard interface protocol 70 -73 46 -86 6378388.000 0.00672267002233 /*hjorsey 1955*/ 71 -156 -271 -189 6378388.000 0.00672267002233 /*hong kong 1963*/ 72 209 818 290 6377276.345 0.00663784663020 /*indian-thai/viet*/ 73 295 736 257 6377301.243 0.00663784663020 /*indian-india/nepal*/ 74 506 -122 611 6377340.189 0.00667053999999 /*ireland 1965*/ 75 208 -435 -229 6378388.000 0.00672267002233 /*ists o73 astro 1969 76 89 -79 -202 6378388.000 0.00672267002233 /*johnston island 1961*/ 77 -97 787 86 6377276.345 0.00663784663020 /*kandawala*/ 78 145 -187 103 6378388.000 0.00672267002233 /*kerguelen island*/ 79 -11 851 5 6377304.063 0.00663784663020 /*kertau 1948*/ 80 94 -948 -1262 6378388.000 0.00672267002233 /*la reunion*/ 81 42 124 147 6378206.400 0.00676865799761 /*l.c. 5 astro*/ 82 -90 40 88 6378249.145 0.00680351128285 /*liberia 1964*/ 83 -133 -77 -51 6378206.400 0.00676865799761 /*luzon-phillippines*/ 84 -133 -79 -72 6378206.400 0.00676865799761 /*luzon-mindanao*/ 85 41 -220 -134 6378249.145 0.00680351128285 /*mahe 1971*/ 86 -289 -124 60 6378388.000 0.00672267002233 /*marco astro*/ 87 639 405 60 6377397.155 0.00667437223180 /*massawa*/ 88 31 146 47 6378249.145 0.00680351128285 /*merchich*/ 89 912 -58 1227 6378388.000 0.00672267002233 /*midway astro 1961*/ 90 -92 -93 122 6378249.145 0.00680351128285 /*minna*/ 91 -247 -148 369 6378249.145 0.00680351128285 /*nahrwan-masirah*/ 92 -249 -156 381 6378249.145 0.00680351128285 /*nahrwan-uae*/ 93 -243 -192 477 6378249.145 0.00680351128285 /*nahrwan-saudia*/ 94 616 97 -251 6377483.865 0.00667437223180 /*namibia*/ 95 -10 375 165 6378388.000 0.00672267002233 /*naparima*/ 96 -8 159 175 6378206.400 0.00676865799761 /*nad 27-western us*/ table a-99 datums (continued) index dx dy dz a-axis eccentricity description www.datasheet.co.kr datasheet pdf - http://www..net/ a-126 acutime 2000 synchronization kit user guide trimble standard interface protocol a 97 -9 161 179 6378206.400 0.00676865799761 /*nad 27-eastern us*/ 98 -5 135 172 6378206.400 0.00676865799761 /*nad 27-alaska*/ 99 -4 154 178 6378206.400 0.00676865799761 /*nad 27-bahamas*/ 100 1 140 165 6378206.400 0.00676865799761 /*nad 27-san salvador*/ 101 -10 158 187 6378206.400 0.00676865799761 /*nad 27-canada*/ 102 -7 162 188 6378206.400 0.00676865799761 /*nad 27-alberta/ bc*/ 103 -22 160 190 6378206.400 0.00676865799761 /*nad 27-east canada*/ 104 -9 157 184 6378206.400 0.00676865799761 /*nad 27-manitoba/ ont*/ 105 4 159 188 6378206.400 0.00676865799761 /*nad 27-nw ter/ sask*/ 106 -7 139 181 6378206.400 0.00676865799761 /*nad 27-yukon*/ 107 0 125 201 6378206.400 0.00676865799761 /*nad 27-canal zone*/ 108 -3 143 183 6378206.400 0.00676865799761 /*nad 27- caribbean*/ 109 0 125 194 6378206.400 0.00676865799761 /*nad 27-central amer*/ 110 -9 152 178 6378206.400 0.00676865799761 /*nad 27-cuba*/ 111 11 114 195 6378206.400 0.00676865799761 /*nad 27- greenland*/ 112 -12 130 190 6378206.400 0.00676865799761 /*nad 27-mexico*/ 113 0 0 0 6378137.0 0.00669438002290 /*nad 83-alaska*/ 114 0 0 0 6378137.0 0.00669438002290 /*nad 83-canada*/ 115 0 0 0 6378137.0 0.00669438002290 /*nad 83-conus*/ 116 0 0 0 6378137.0 0.00669438002290 /*nad 83-mex/cent am*/ 117 -425 -169 81 6378388.0 0.00672267002233 /*observatorio 1966*/ table a-99 datums (continued) index dx dy dz a-axis eccentricity description www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-127 a trimble standard interface protocol 118 -130 110 -13 6378200.0 0.00669342162297 /*old egyptian 1907*/ 119 61 -285 -181 6378206.400 0.00676865799761 /*old hawaiian- mean*/ 120 89 -279 -183 6378206.400 0.00676865799761 /*old hawaiian- hawaii*/ 121 45 -290 -172 6378206.400 0.00676865799761 /*old hawaiian*/ 122 65 -290 -190 6378206.400 0.00676865799761 /*old hawaiian*/ 123 58 -283 -182 6378206.400 0.00676865799761 /*old hawaiian*/ 124 -346 -1 224 6378249.15 0.00680351128285 /*oman*/ 125 375 -111 431 6377563.4 0.00667053999999 /*ord sur brit ?36- mean*/ 126 375 -111 431 6377563.4 0.00667053999999 /*osb-england*/ 127 375 -111 431 6377563.4 0.00667053999999 /*osb-isle of man*/ 128 375 -111 431 6377563.4 0.00667053999999 /*osb-scotland/ shetland*/ 129 375 -111 431 6377563.4 0.00667053999999 /*osb-wales*/ 130 -307 -92 127 6378388.0 0.00672267002233 /*pico de las nieves*/ 131 -185 165 42 6378388.0 0.00672267002233 /*pitcairn astro 1967*/ 132 16 196 93 6378388.0 0.00672267002233 /*prov so chilean1963*/ 133 -288 175 -376 6378388.0 0.00672267002233 /*prov s. american 1956-mean*/ 134 -270 188 -388 6378388.0 0.00672267002233 /*prov s. american 1956-bolivia*/ 135 -270 183 -390 6378388.0 0.00672267002233 /*prov s. american 1956-n chile*/ 136 -305 243 -442 6378388.0 0.00672267002233 /*prov s. american 1956-s chile*/ 137 -282 169 -371 6378388.0 0.00672267002233 /*prov s. american 1956-colom*/ table a-99 datums (continued) index dx dy dz a-axis eccentricity description www.datasheet.co.kr datasheet pdf - http://www..net/ a-128 acutime 2000 synchronization kit user guide trimble standard interface protocol a 138 -278 171 -367 6378388.0 0.00672267002233 /*prov s. american 1956-equador*/ 139 -298 159 -369 6378388.0 0.00672267002233 /*prov s. american 1956-guyana*/ 140 -279 175 -379 6378388.0 0.00672267002233 /*prov s. american 1956-peru*/ 141 -295 173 -371 6378388.0 0.00672267002233 /*prov s. american 1956-venez*/ 142 11 72 -101 6378206.4 0.00676865799761 /*puerto rico*/ 143 -128 -283 22 6378388.0 0.00672267002233 /*quatar national*/ 144 164 138 -189 6378388.0 0.00672267002233 /*qornoq*/ 145 -225 -65 9 6378388.0 0.00672267002233 /*rome 1940*/ 146 -203 141 53 6378388.0 0.00672267002233 /*santa braz*/ 147 170 42 84 6378388.0 0.00672267002233 /*santo (dos)*/ 148 -355 21 72 6378388.0 0.00672267002233 /*sapper hill 1943*/ 149 -57 1 -41 6378160.0 0.00669454185459 /*s. american 1969- mean*/ 150 -62 -1 -37 6378160.0 0.00669454185459 /*s. american 1969- argentina*/ 151 -61 2 -48 6378160.0 0.00669454185459 /*s. american 1969- bolivia*/ 152 -60 -2 -41 6378160.0 0.00669454185459 /*s. american 1969- brazil*/ 153 -75 -1 -44 6378160.0 0.00669454185459 /*s. american 1969- chile*/ 154 -44 6 -36 6378160.0 0.00669454185459 /*s. american 1969- colombia*/ 155 -48 3 -44 6378160.0 0.00669454185459 /*s. american 1969- ecuador*/ 156 -53 3 -47 6378160.0 0.00669454185459 /*s. american 1969- guyana*/ 157 -61 2 -33 6378160.0 0.00669454185459 /*s. american 1969- paraguay*/ table a-99 datums (continued) index dx dy dz a-axis eccentricity description www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-129 a trimble standard interface protocol 158 -58 0 -44 6378160.0 0.00669454185459 /*s. american 1969- peru*/ 159 -45 12 -33 6378160.0 0.00669454185459 /*s. american 1969- trin/tob*/ 160 -45 8 -33 6378160.0 0.00669454185459 /*s. american 1969- venezuela*/ 161 7 -10 -26 6378155.0 0.00669342162297 /*south asia*/ 162 -499 -249 314 6378388.0 0.00672267002233 /*southeast base*/ 163 -104 167 -38 6378388.0 0.00672267002233 /*southwest base*/ 164 -689 691 -46 6377276.345 0.00663784663020 /*timbalai 1948*/ 165 -148 507 685 6377397.16 0.00667437223180 /*tokyo-mean*/ 166 -146 507 687 6377397.16 0.00667437223180 /*tokyo-korea*/ 167 -158 507 676 6377397.16 0.00667437223180 /*tokyo-okinawa*/ 168 -632 438 -609 6378388.0 0.00672267002233 /*tristan astro 1968*/ 169 51 391 -36 6378249.15 0.00680351128285 /*viti levu 1916*/ 170 102 52 -38 6378270.0 0.00672267002233 /*wake-eniwetok*/ 171 -265 120 -358 6378388.0 0.00672267002233 /*zanderij*/ 172 -384 664 -48 6377397.16 0.00667437223180 /*bukit rimpah*/ 173 -104 -129 239 6378388.0 0.00672267002233 /*camp area astro*/ 174 -403 684 41 6377397.16 0.00667437223180 /*gunung segara*/ 175 -333 -222 114 6378388.0 0.00672267002233 /*herat north*/ 176 -637 -549 -203 6378388.0 0.00672267002233 /*hu-tzu-shan*/ 177 -189 -242 -9 6378388.0 0.00672267002233 /*tananarive observ. 1925*/ 178 -155 171 37 6378388.0 0.00672267002233 /*yacare*/ 179 -146.43 507.89 681.46 6377397.155 0.00667437223180 /*tokyo gsi coords*/ table a-99 datums (continued) index dx dy dz a-axis eccentricity description www.datasheet.co.kr datasheet pdf - http://www..net/ a-130 acutime 2000 synchronization kit user guide trimble standard interface protocol a a.18 sample tsip routines the following sections give sample routines that use command packet 0x1f and report packet 0 45 for getting software version information from the acutime 2000 via com1. source code for a working tsip monitor program is available at www.trimble.com/ support/files . sending out tsip command packet 0x1f in general, all tsip packets use the structure tsippkt: #define max_rptbuf 256 typedef struct { short cnt; /* size of buf */ unsigned char status, /* tsip packet format and parse status */ code, /* tsip id code */ buf[max_rptbuf]; /* command or report string */ } tsippkt; communication with the acutime 2000 is accomplished through command routines and report routines. each command routine use send_cmd() which supplies the dle stuffing to the command string and sends the command to the serial port using the primitive function sendb() . www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide a-131 a trimble standard interface protocol all tsip packet formats take the form a-132 acutime 2000 synchronization kit user guide trimble standard interface protocol a to issue command packet 0x41 to request software version from the acutime 2000 use the following routine. /* request software version */ void cmd_0x1f(void) { tsippkt cmd; cmd.cnt = 0; cmd.code = 0x1f; send_cmd(&cmd); } handling incoming tsip packet 0x45 report routines handle incoming receiver packets. they call the routine end_of_rptpkt() which accumulates from the serial buffer, unstuffs these bytes, and checks whether the end-of-packet sequence acutime 2000 synchronization kit user guide a-133 a trimble standard interface protocol case etx: /* end of message. */ rpt->status = complete; return(true); default: /* if previous message has ended, this is new id code. */ reset_rptbuf(rpt); /* if not, this is an error. */ rpt->code = this_byte; return(false); } } else if (this_byte == dle) { /* dle byte without previous dle stuffing?must be stuffing. */ rpt->status = have_dle; continue; } /* normal byte; add to report */ rpt->status = incomplete; rpt->buf[rpt->cnt] = this_byte; rpt->cnt++; if (rpt->cnt > max_rptbuf) { reset_rptbuf (rpt); return(false); } } } /* prepare for receipt of new report */ void reset_rptbuf (tsippkt *rpt) { rpt->cnt = 0; rpt->code = etx; rpt->status = incomplete; } www.datasheet.co.kr datasheet pdf - http://www..net/ a-134 acutime 2000 synchronization kit user guide trimble standard interface protocol a www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide b-1 b timing receiver monitor the timing receiver monitor program disk is included with the acutime 2000 synchronization kit. the latest version of the program is also available on the trimble website: ? www.trimble.com/products/ACUTIME2000 b.1 start-up the serial port selection screen shown below appears at the start of the program: this screen lets you choose which pc serial port the ace utc is connected to. if the desired port is not available in the selection box, you can start the program using the parameter ?c*, with * being the number of the serial port you want to select. www.datasheet.co.kr datasheet pdf - http://www..net/ b-2 acutime 2000 synchronization kit user guide timing receiver monitor b b.2 main screen the main screen for the timing receiver monitor is shown below: the main screen displays time, position, sv selection and data, receiver status, and timing outputs. the status bar displays tx and rx activity, program hints, firmware version number, and serial port settings. the menu provides other options for sending data to and requesting data from the receiver. for additional program information and help, see the help menu. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide c-1 c nmea 0183 nmea 0183 is an interface protocol created by the national marine electronics association. the latest release of nmea 0183 is version 2.1 (october 15, 1995). this protocol was originally established to allow marine navigation equipment to share information. nmea 0183 is a simple, yet comprehensive ascii protocol which defines both the communication interface and the data format. since it is a well established industry standard, nmea 0183 has also gained popularity for use in applications other than marine electronics. for those applications requiring output only from the gps receiver, nmea 0183 is a popular choice since, in many cases, an nmea 0183 software application code already exists. the acutime 2000 gps smart antenna is available with firmware that supports a subset of the nmea 0183 messages: gga and vtg. for a nominal fee, trimble can offer custom firmware with a different selection of messages to meet your application requirements. this appendix provides a brief overview of the nmea protocol and describes both the standard and optional messages offered by the ace utc. for a complete copy of the nmea 0183 standard, contact: nmea national office po box 3435 new bern, nc 28564-3435 u.s.a. telephone: +1-919-638-2626 fax: +1-919-638-4885 www.datasheet.co.kr datasheet pdf - http://www..net/ c-2 acutime 2000 synchronization kit user guide nmea 0183 c c.1 the nmea 0183 communication interface nmea 0183 allows a single source (talker) to transmit serial data over a single twisted wire pair to one or more receivers (listeners). the table below lists the characteristics of the nmea 0183 data transmissions. c.2 nmea 0183 message format the nmea 0183 protocol covers a broad array of navigation data. this broad array of information is separated into discrete messages, which convey a specific set of information. the entire protocol encompasses over 50 messages, but only a sub-set of these messages apply to a gps receiver like the ace utc. the nmea message structure is described below. $idmsg,d1,d2,d3,d4,.......,dn*cs[cr][lf] ?$? the ?$? signifies the start of a message. id the talker identification is a two-letter mnemonic that describes the source of the navigation information. the gp identification signifies a gps source. msg the message identification is a three-letter mnemonic that describes the message content and the number and order of the data fields. ?,? commas serve as delimiters for the data fields. table c-1 nmea 0183 characteristics signal characteristic nmea standard baud rate 4800 data bits 8 parity none (disabled) stop bits 1 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide c-3 c nmea 0183 dn each message contains multiple data fields (dn), which are delimited by commas. ?*? the asterisk serves as a checksum delimiter. cs the checksum field contains two ascii characters which indicate the hexadecimal value of the checksum. [cr][lf] the carriage return [cr] and line feed [lf] combination terminate the message. nmea 0183 messages vary in length, but each message is limited to 79 characters or less. this length limitation excludes the ?$? and the [cr][lf]. the data field block, including delimiters, is limited to 74 characters or less. www.datasheet.co.kr datasheet pdf - http://www..net/ c-4 acutime 2000 synchronization kit user guide nmea 0183 c c.3 nmea 0183 message options the acutime 2000 can output any or all of the messages listed in table c-2. when nmea is chosen, its default configuration (as shipped from the factory) outputs two messages: gga and vtg. these messages are output at a one-second interval with the ?gp? talker id and checksums. * note ? the user can configure a custom mix of the messages listed in table c-2. see port a (timing), page 5-11, and tsip command packets 0xbc, 0x7a, and 0x8e 0x26 in appendix a, trimble standard interface protocol, for details on configuring nmea output. m warning ? if too many messages are specified for output, you may need to increase the unit?s baud rate. table c-2 acutime 2000 nmea messages setting message description default gga gps fix data (nmea version 2.1) gll geographic position - latitude/ longitude gsa gps dop and active satellites gsv gps satellites in view rmc recommended minimum specific gps/ transit data default vtg track made good and ground speed zda time & date www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide c-5 c nmea 0183 c.4 nmea 0183 message formats the format for each message is described in more detail in the following sections. c.4.1 gga ? gps fix data the gga message includes time, position and fix related data for the gps receiver. $gp gga,hhmmss,llll.lll,a,nnnnn.nnn,b,t,uu,v.v,w.w, m,x.x,m,y.y,zzzz*hh c-6 acutime 2000 synchronization kit user guide nmea 0183 c c.4.2 gll ? geographic position ? latitude/longitude the gll message contains the latitude and longitude of the present vessel position, the time of the position fix and the status. $gp gll,llll.lll,a,yyyyy.yyy,a,hhmmss.s, a*hh acutime 2000 synchronization kit user guide c-7 c nmea 0183 c.4.3 gsa ? gps dop and active satellites the gsa messages indicates the gps receiver's operating mode and lists the satellites used for navigation and the dop values of the position solution. $gp gsa,a,x,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx, xx,xx,x.x,x.x,x.x*hh c-8 acutime 2000 synchronization kit user guide nmea 0183 c c.4.4 gsv ? gps satellites in view the gsv message identifies the gps satellites in view, including their prn number, elevation, azimuth and snr value. each message contains data for four satellites. second and third messages are sent when more than four satellites are in view. fields #1 and #2 indicate the total number of messages being sent and the number of each message respectively. $gp gsv,x,x,xx,xx,xx,xxx,xx,xx,xx,xxx,xx,xx,xx, xxx,xx,xx,xx,xxx,xx*hh acutime 2000 synchronization kit user guide c-9 c nmea 0183 c.4.5 rmc ? recommended minimum specific gps/transit data the rmc message contains the time, date, position, course, and speed data provided by the gps navigation receiver. a checksum is mandatory for this message and the transmission interval may not exceed two seconds. all data fields must be provided unless the data is temporarily unavailable. null fields may be used when data is temporarily unavailable. $gp rmc,hhmmss.s,a,llll.lll,a,yyyyy.yyy,a,x.x,x.x, xxxxxx,x.x,a*hh c-10 acutime 2000 synchronization kit user guide nmea 0183 c c.4.6 vtg ? track made good and ground speed the vtg message conveys the actual track made good (cog) and the speed relative to the ground (sog). $gp vtg,x.x,t,x.x,m,x.x,n,x.x,k*hh acutime 2000 synchronization kit user guide c-11 c nmea 0183 c.4.7 zda ? time & date the zda message contains utc, the day, the month, the year and the local time zone. $gp zda,hhmmss.s,xx,xx,xxxx,,*hh c-12 acutime 2000 synchronization kit user guide nmea 0183 c www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide d-1 d specifications and drawings this appendix contains the specifications for the acutime 2000 gps smart antenna and a diagram of the acutime 2000 interface cable. * note ? the interface cable specifications provided in this appendix are for the 100-foot (30-meter) versions of the cables. longer versions of these cables are available. the specifications for the longer cables are identical to that of the 100-foot version. d.1 acutime 2000 gps smart antenna specifications the following tables list the specifications for the acutime 2000 gps smart antenna. table d-1 physical specifications dimensions: 6.12" d, 5.0" h (155.5mm x 127.0mm) weight: 12.8 oz. (363 g) connector: 12-pin round, waterproof mounting: 1"-14 straight thread dimensions: height: 5.0" (127 mm) width: 6.12" (155.5 mm) www.datasheet.co.kr datasheet pdf - http://www..net/ d-2 acutime 2000 synchronization kit user guide specifications and drawings d table d-2 environmental specifications operating temp: -40 to +85 c storage temp: -55 to +105 c vibration: 0.008 g 2 /hz 5 hz to 20 hz 0.05 g 2 /hz 20 hz to 100 hz -3db/octave 100 hz to 900 hz operating humidity: 95% rh, non-condensing @ 60 c emc: ce, fcc class b table d-3 performance specifications general: l1 frequency, c/a code (sps), continuous tracking receiver. available in 8-channel update rate: 1hz accuracy: dynamic sps (with s/a) dynamic dgps position 40m cep 1.5m cep velocity 0.25 m/s cep 0.05 m/s cep time to first fix (no stored position): 8-channel typical cold start: < 120 seconds time to first pps (stationary with stored position, e.g., recovery after power outage): <60 seconds re-acquisition after 60-second signal loss: <2 seconds (90%) dynamics: velocity: 500 m/sec. maximum www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide d-3 d specifications and drawings acceleration: 4g (39.2 m/sec. 2 ) jerk: 20 m/sec. 3 pps output physical interface: rs-422 width: 10 microseconds (default). user-programmable from 10 microseconds to 500 milliseconds. on-time edge: rising edge on-time (default). user-programmable rising or falling. resolution: 80 nanoseconds (quantization error reported through tsip) accuracy (one sigma): utc 50 nanoseconds (static) utc 150 nanoseconds (dynamic, tdop 3) external event capture interface: rs-422/485 or rs-232 resolution: 320 nanoseconds minimum pulse width: 1 microsecond, rising edge on-time reporting mechanism: tsip packet table d-4 electrical specifications prime power: +8 vdc to +36 vdc, reverse polarity protection power consumption: 110ma @ 12 volts, 1.3 watts (typical), <1.5 watts max table d-3 performance specifications (continued) www.datasheet.co.kr datasheet pdf - http://www..net/ d-4 acutime 2000 synchronization kit user guide specifications and drawings d table d-5 serial protocols port interface protocols defaults txb (primary) rs-422/485 or rs-232 tsip, nmea tsip @ 9600, 8-odd-1 rxb (primary) rs-422/485 or rs-232 tsip tsip @ 9600, 8-odd-1 txa (secondary) rs-422/485 or rs-232 tsip tsip @ 9600, 8-odd-1 rxa (secondary) rs-422/485 or rs-232 event/rtcm event input all ports support baud rates of 300-38,400; 8 data bits; even, odd, no parity nmea messages (default): zda available messages: gga, gll, vtg, gsv, gsa, zda, rmc www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide d-5 d specifications and drawings d.2 acutime 2000 standard interface cable diagram figure d-1 provides a technical drawing of the acutime 2000 standard interface cable. www.datasheet.co.kr datasheet pdf - http://www..net/ d6 specifications and drawings d figure d-1 acutime 2000 standard interface cable color red black violet orange brown yellow white gray green blue orange/wht black/wht unins. pin # 1 9 2 3 4 5 6 7 8 10 12 nc 11 nc 1 pps signal gnd vflash receive a transmit a vbackup rts transmit b cts receive b ground power signal rs232 drain wires nc signal rs422 1 pps - 1 pps + vflash vbackup rtcm in + rtcm in - transmit + transmit - receive + receive - ground power paired paired paired paired paired paired wires 50' 6" 1.6"0.1" ref 4.0" 1.0" part number/rev level label pin 10 pin 1 pin 9 pin 12 pin 5 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide e-1 e theory of operation this chapter describes the smart antenna's satellite acquisition and tracking processes, performance characteristics and system architecture. this discussion assumes you are familiar with basic gps theory. the smart antenna's satellite acquisition and tracking algorithms can achieve a position solution without any initialization. the receiver tracks up to eight satellites and automatically selects the best combination of satellites to compute position, velocity and time. as satellites move out of view, the smart antenna automatically acquires new satellites and includes them in the solution set as required. before proceeding to the detailed discussion of the satellite acquisition and tracking process, please review the gps satellite message description on the next page. www.datasheet.co.kr datasheet pdf - http://www..net/ e-2 acutime 2000 synchronization kit user guide theory of operation e e.1 gps satellite message every gps satellite transmits the coarse/acquisition (c/a) code and satellite data modulated onto the l1 carrier frequency (1575.42 mhz). the c/a code is a unique pseudo-random sequence for each satellite. the satellite data transmitted by each satellite includes a satellite almanac for the entire gps system, its own satellite ephemeris, and its own clock correction. the satellite data is transmitted in 30-second frames. each frame contains the clock correction and ephemeris for that specific satellite, and two pages of the 50-page gps system almanac. the time required to transmit the complete system almanac is 12.5 minutes; the time to transmit the satellite ephemeris is 30 seconds. the system almanac contains information about each of the satellites in the constellation, ionospheric data, and special system messages. the ephemeris contains detailed orbital information for a specific satellite. the gps system almanac changes infrequently and is typically valid for weeks. ephemeris data changes hourly, but is valid for up to four hours. the gps control segment updates the system almanac weekly and the ephemeris hourly through three ground- based control stations. during normal operation, the smart antenna updates the ephemeris stored in its memory at 30-minute intervals. the performance of a gps receiver at power-on is determined largely by the availability and accuracy of the satellite ephemeris data and the availability of a gps system almanac. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide e-3 e theory of operation e.2 satellite acquisition and time to first fix this section describes satellite acquisition times for different start conditions. e.2.1 cold start the term cold start describes the performance of a gps receiver at power-on when no navigation data is available. cold signifies that the receiver does not have a current almanac, satellite ephemeris, initial position, or time. the cold start search algorithm applies to a smart antenna that is powered on without the memory backup circuit connected to a source of dc power. since the acutime 2000 has no provision for external backup power, it always operates from a cold start. this is the condition of the gps module as received from the factory. in a cold start condition, the receiver automatically selects a set of satellites and dedicates an individual tracking channel to search the doppler frequency for each satellite in the set. if none of the selected satellites are acquired after a pre-determined period of time (time-out), the receiver selects a new search set of satellites and repeats the process until the first satellite is acquired. as satellites are acquired, the receiver automatically collects ephemeris and almanac data. the smart antenna uses the information gained from acquiring a specific satellite to eliminate other satellites (those below the horizon) from the search set. this strategy speeds the acquisition of additional satellites required to achieve the first position fix. the cold start search sets are established to ensure that at least three satellites are acquired within the first two time-out periods. as soon as four satellites are acquired, the receiver computes an initial position fix. the acutime 2000 typically achieves a cold start in under two minutes. a complete system almanac is not required to achieve a first position fix. the almanac is used in subsequent warm starts , and to aid in acquiring gps satellites that come into view. www.datasheet.co.kr datasheet pdf - http://www..net/ e-4 acutime 2000 synchronization kit user guide theory of operation e e.2.2 warm start in a warm start condition, the receiver has a current almanac, an initial position (within 3,000 km) and current time (within five minutes) stored in memory. although the smart antenna does not have an onboard battery for preserving memory, it can be initialized using the tsip protocol. to force a warm start, the almanac, time, and initial position must be uploaded to the receiver. during a warm start, the smart antenna identifies the satellites that are expected to be in view, given the system almanac, the initial position and the time. the receiver calculates the elevation and expected doppler shift for each satellite in this expected set and directs the eight tracking channels in a parallel search for these satellites. if the internal oscillator error is known, the smart antenna compensates for the offset to optimize the search. if the offset is not known, the search algorithms are set wide enough to allow for oscillator tolerance, aging, and temperature errors. if the receiver has an almanac and an initial position, but does not have the current time, it executes a cold start search until the first satellite is acquired. once this first satellite is acquired, the receiver can obtain an approximate time and will convert to warm start mode to acquire additional satellites. although the time to first fix is slightly longer in this case, it is significantly shorter than a complete cold start. the warm start time to first fix is usually less than 50 seconds (40 seconds is typical). www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide e-5 e theory of operation e.2.3 "garage search" strategy during a warm start search, the smart antenna knows which satellites to search for, based on the system almanac, the initial position and the current time. in some cases, the receiver may not be able to acquire the expected satellite signals (for example, if the acutime 2000 is in a jamming environment). trimble's patented garage search strategy, also known as a split search, is designed for such situations. if the receiver does not acquire the expected set of satellites within five minutes of a warm start, one of the channels is directed in a cold start search. this strategy minimizes the time to first fix in cases where the stored almanac, position and time are invalid. if the cold start search proves effective and the garage search fails, the stored information is flushed from memory. e.2.4 hot start a hot start strategy applies when the almanac, position, time and ephemeris in memory are valid. the hot start search strategy is similar to a warm start, but since the ephemeris data in memory is considered current and valid, the acquisition time is typically less than 30 seconds. this may occur if the gps signals are temporarily obscured or jammed. www.datasheet.co.kr datasheet pdf - http://www..net/ e-6 acutime 2000 synchronization kit user guide theory of operation e e.3 position accuracy gps position accuracy is degraded by atmospheric distortion, satellite and receiver clock errors, and selective availability (s/a). effective models for atmospheric distortion of satellite signals have been developed to minimize the impact of tropospheric and ionospheric effects. the impact of satellite clock errors is minimized by incorporating the clock corrections transmitted by each satellite used in the position solution. s/a is the most significant contributor to position error and cannot be effectively counteracted except with differential gps. e.3.1 selective availability (s/a) the u.s. department of defense, through a program called selective availability, intentionally degrades gps accuracy for civilian users. the s/a program creates position errors by modifying the apparent position of each satellite and introducing random dither into each satellite's clock. in extreme cases, all sources of error (natural, pdop, and s/a) can combine to produce large position errors. the dod's definition of accuracy under s/a is 100 meters 2 drms (horizontal two- dimensional, 95 percent of the time). www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide e-7 e theory of operation e.4 coordinate systems this section lists the coordinate system formats supported by the tsip and nmea 0183 protocols. e.4.1 tsip in the default tsip configuration, position is output in a latitude- longitude-altitude (lla) format based on a default datum, wgs-84. the lla format can be easily converted by the host system to other coordinate systems using the appropriate translation algorithm. by sending the appropriate tsip command, the smart antenna's position output can be changed to a cartesian (xyz) coordinate format. the datum used for lla transformations can also be changed using the tsip 8e packet. the smart antenna offers a selection of 179 datums , which are listed in appendix a, trimble standard interface protocol. the tsip velocity output format is also three-dimensional. the default format is x-y-z with the option of an east-north-up (enu) coordinate format. time tags on fix messages default to utc (universal coordinated time), but can be switched to gps time by sending the appropriate tsip command. e.4.2 nmea 0183 the nmea 0183 protocol supports only lla format and utc time. if a custom datum is required, it can be set through tsip using command 0x8e-15. www.datasheet.co.kr datasheet pdf - http://www..net/ e-8 acutime 2000 synchronization kit user guide theory of operation e e.5 performance characteristics this section lists performance information for the acutime 2000. e.5.1 update rate the acutime 2000 updates position at one-second intervals during self-survey. the surveyed position is frozen after the survey completes. e.5.2 dynamic limits the dynamic operating limits for the various receiver designs are listed below. these operating limits assume that the smart antenna is correctly installed and that the overall system is designed to operate under the same dynamic conditions. e.5.3 re-acquisition when a satellite signal is momentarily interrupted during normal operation, the receiver continues to search for the lost signal at the satellite's last known doppler frequency. if the lost signal is not re- acquired within 15 seconds, the receiver initiates a broader frequency search. the smart antenna uses the last known information about the dynamics of the receiver and the satellite to establish the center frequency and range for the search. every 15 seconds, until the lost signal is re-acquired, a new center frequency and search range is computed. each frequency range is searched in 500 hz increments. the duration of the code search at a given frequency is approximately one second and switches automatically. table e-1 dynamic upper bound dynamic operating limits velocity 500 m/s acceleration 4 g (39.2 m/s 2 ) jerk 20 m/s 3 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide e-9 e theory of operation if ephemeris or almanac data is available for the lost satellite, then the satellite's velocity is factored into the center frequency calculation. the diminished accuracy of an older almanac is accounted for in the width of the search range. if neither the ephemeris nor almanac is available, then the doppler frequency at last lock is searched for two minutes. if the satellite has not been re-acquired after two minutes, then the maximum expected doppler frequency, based on satellite dynamics, is searched. if the current position is not accurately known, the search width is increased. if the smart antenna is computing velocity or velocity aiding is provided, then the receiver's motion is also factored into the doppler frequency. if velocity information is not available, then the dynamics code is used to determine the maximum expected doppler frequency. the re-acquisition time for momentary signal blockages is typically under two seconds. www.datasheet.co.kr datasheet pdf - http://www..net/ e-10 acutime 2000 synchronization kit user guide theory of operation e e.6 system architecture the standard acutime 2000 incorporates a proprietary dsp (digital signal processor), which operates at the l1 frequency (1575.42 mhz) and processes the coarse/acquisition (c/a) code portion of the gps signal. the rf and digital signal processing components of the gps module are custom asics designed by trimble. in addition to the signal processing functions, these asics also contain support circuitry for the microprocessor. the microprocessor performs the navigation computations in addition to controlling the dsp channels and managing the i/o operations. gps satellite signals are collected by the antenna, filtered and amplified by the antenna's pre-amp and then fed to the rf down converter. a highly stable, crystal reference oscillator, operating at 12.504 mhz, supports the down converter in producing the correct signals for the digital signal processor. the signal processing stage tracks the gps satellite signals and extracts the carrier code information, as well as the navigation data at 50 bits per second. in addition to supporting the down conversion process, the crystal oscillator also serves as the reference clock for the navigation processor. this microprocessor controls the operation of the signal processing channels by allocating the channels during satellite acquisition and tracking. in the overdetermined mode of operation, the smart antenna automatically tracks the highest eight (or twelve) satellites above the horizon and selects the optimal set of satellites for the position solution. in addition to controlling the dsp stage, the navigation processor also collects the ephemeris and almanac data for all of the satellites and manages the universal asynchronous receiver/transmitter (uart or duart) interface. the uart supports full-duplex serial communication with the smart antenna. the rs-232 and rs-422 versions of the acutime 2000 block diagram for the gps smart antenna are illustrated in figure e-1 and figure e-2. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide e-11 e theory of operation figure e-1 acutime 2000 block diagram (rs-232 version) figure e-2 acutime 2000 block diagram (rs-422 version) microcontroller/ gps receiver asic preamp internal patch antenna switching power supply rf in tx rx tx pps out event in port a port b vcc rf asic flash eprom ram tcxo 12.504mhz clk in mcu bus 4 9 1 7 2 port b tx event in / port a rx pps out (+) pps out (-) dc power in ground acutime 2000 12-pin connector port b rx port a tx rx 11 12 6 vback 8 backup voltage microcontroller/ gps receiver asic preamp + - + - internal patch antenna switching power supply rf in tx rx tx pps out event in port a port b vcc rf asic flash eprom ram tcxo 12.504mhz clk in mcu bus 5 4 9 1 12 11 6 7 8 10 2 3 port b tx(+) port b tx(-) port b rx(+) port b rx(-) port a tx(+) port a tx(-) event in / port a rx (+) event in / port a rx (-) pps out (+) pps out (-) dc power in ground acutime 2000 12-pin connector rx www.datasheet.co.kr datasheet pdf - http://www..net/ e-12 acutime 2000 synchronization kit user guide theory of operation e www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide glossary-1 glossary this section defines technical terms and abbreviations used in this manual. it includes terms from the field of gps technology. 2-d two dimensional. a 2-d position is defined as latitude and longitude. altitude is assumed to be fixed. 2-d gps mode a procedure of determining a 2-d position using signals received from the best (or only) three available gps satellites. altitude is assumed to be known and constant. a 2-d position solution will only be determined if signals from three or more satellites are available. 3-d three dimensional. a 3-d position is defined as latitude, longitude, and altitude. 3-d gps mode a procedure of determining a 3-d position using signals received from the best (or only) four available gps satellites. a 3-d position solution will only be determined if signals from four or more satellites are available. almanac a reduced-precision subset of the ephemeris parameters. used by the receiver to compute the elevation angle, azimuth angle, and estimated doppler of the satellites. each satellite broadcasts the almanac for all the satellites in the system. www.datasheet.co.kr datasheet pdf - http://www..net/ glossary-2 acutime 2000 synchronization kit user guide glossary ascii american standard code for information interchange. a standard set of 128 characters, symbols and control codes used for computer communications. ascii characters require 7 bits of data to send, but are often sent 8 bits at a time with the extra bit being a zero. auto gps mode a procedure of automatically determining either a 2-d or 3- d position using signals received from gps satellites. the solution automatically transitions between 2-d and 3-d depending on the number of satellites available, the pdop of the available satellites, and the defined pdop switch value. (see pdop and pdop constellation switch). azimuth angle the angle of the line-of-site vector, projected on the horizontal plane, measured clockwise from true north. bandwidth the range of frequencies occupied by a signal. also, the information carrying capability of a communication channel or line. baud a measure of the speed of data transmission. baud and bit rate are the same for direct equipment interconnections (for example, through rs-232). baud and bit rate are not the same for modulated data links, whether wire or radio. bit binary digit. the smallest unit of information into which digital data can be subdivided and which a computer can hold. each bit has only two values (e.g., on/off, one/zero, true/false). bit rate the rate at which bits are transmitted over a communication path. normally expressed in bits per second (bps). byte a set of contiguous bits that make up a discrete item of information. a byte usually consists of a series of 8 bits, and represents one character. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide glossary-3 glossary c/a code the coarse/acquisition code. this is the civilian code made available by the department of defense. it is subject to selective availability (sa). users can reduce the effects of sa by using differential gps. carrier the radio signal on which information is carried. the carrier can be sensed to determine the presence of a signal. channel either a single frequency or a pair of radio frequencies used as a communication path. chip the length of time to transmit either a zero or a one in a binary pulse code. chip rate number of chips per second (e.g., c/a code = 1.023 mhz). configuration a set of conditions or parameters that define the structure of an item. in regards to placer, a configuration defines the gps processing and characteristics of the rs-232 interface ports. the term configuration can also define the hardware components that comprise a subsystem or system. data bits the bits in a byte of data which carry the actual information. datum a mathematical model of the earth. many local datums model the earth for a small region: for example, tokyo datum, alaska, nad-27 (north america). others, such as wgs-84, model the whole earth. dce data communications equipment. the equipment that provides the functions required to establish, maintain, and terminate a communication connection. any equipment that connects to dte using an rs-232 or ccitt v.24 standard interface. www.datasheet.co.kr datasheet pdf - http://www..net/ glossary-4 acutime 2000 synchronization kit user guide glossary default setting a preset or initial value that is assumed to be the preferred or appropriate selection for most situations. the placer gps sensor is shipped with factory default configuration settings; the settings were determined by trimble. differential relative positioning determination of relative coordinates of two or more receivers which are simultaneously tracking the same satellites. static differential gps involves determining baseline vectors between pairs of receivers. also see differential gps. dilution of precision a description of the purely geometrical contribution to the uncertainty in a position fix, given by the expression dop = sqrt trace (a a) where a a is the design matrix for the instantaneous position solution (dependent on satellite- receiver geometry). the dop factor depends on the parameters of the position-fix solution. standard terms for the gps application are: gdop ? geometric (three position coordinates plus clock offset in the solution) pdop ? position (three coordinates) hdop ? horizontal (two horizontal coordinates) vdop ? vertical (height only) tdop ? time (clock offset only) rdop ? relative (normalized to 60 seconds) dop see dilution of precision . doppler shift the apparent change in frequency of a received signal due to the rate of change of the range between the transmitter and receiver. earth-centered earth-fixed (ecef) cartesian coordinate system where the x direction is the intersection of the prime meridian (greenwich) with the equator. the vectors rotate with the earth. z is the direction of the spin axis. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide glossary- glossary elevation angle the angle between the line of sight vector and the horizontal plane. elevation mask angle a measure of the minimum elevation angle, above the horizon, above which a gps satellite must be located before the signals from the satellite will be used to compute a gps location solution. satellites below the elevation angle are considered unusable. the elevation mask angle is used to prevent the gps receiver from computing position solutions using satellites which are likely to be obscured by buildings or mountains. ellipsoid in geodesy, unless otherwise specified, a mathematical figure formed by revolving an ellipse about its minor axis. it is often used interchangeably with spheroid. two quantities define an ellipsoid; these are usually given as the length of the semi-major axis, a, and the flattening, f = (a - b)/a, where b is the length of the semi-minor axis. ephemeris a set of parameters that describe the satellite orbit very accurately. it is used by the receiver to compute the position of the satellite. this information is broadcast by the satellites. epoch measurement interval or data frequency, as in making observations every 15 seconds. loading data using 30- second epochs means loading every other measurement. firmware a set of software computer/processor instructions that are permanently or semi-permanently resident in read-only memory. www.datasheet.co.kr datasheet pdf - http://www..net/ glossary- acutime 2000 synchronization kit user guide glossary frequency the number of vibrations per second of an audio or radio signal. measured in hertz (hz), kilohertz (khz), or megahertz (mhz). gps frequencies are: l1 = 1575.42 mhz l2 = 1227.60 mhz gdop geometric dilution of precision. gdop describes how much an uncertainty in pseudo-range and time affects the uncertainty in a position solution. gdop depends on where the satellites are relative to the gps receiver and on gps clock offsets. geodetic datum a mathematical model designed to best fit part or all of the geoid. it is defined by an ellipsoid and the relationship between the ellipsoid and a point on the topographic surface established as the origin of datum. this relationship can be defined by six quantities, generally (but not necessarily) the geodetic latitude, longitude, and the height of the origin, the two components of the deflection of the vertical at the origin, and the geodetic azimuth of a line from the origin to some other point. the gps uses wgs-84. geoid the actual physical shape of the earth which is hard to describe mathematically because of the local surface irregularities and sea-land variations. in geodetic terms it is the particular equipotential surface which coincides with mean sea level, and which may be imagined to extend through the continents. this surface is everywhere perpendicular to the force of gravity. gpd gps with differential corrections applied. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide glossary- glossary gps global positioning system. a satellite-based navigation system operated and maintained by the u.s. department of defense and consisting of a constellation of 24 satellites providing worldwide, 24-hour, three-dimensional (3-d) gps coverage. these satellites transmit signals used (by gps receivers) to determine precise location (position, velocity, and time) solutions. gps signals are available in all weather conditions. this system also includes 5 monitor ground stations, 1 master control ground station, and 3 upload ground stations. gps is emerging as the technology of choice in many timing applications, including site and network synchronization. gps antenna an antenna designed to receive gps radio navigation signals. gps processor an electronic device that interprets the gps radio navigation signals (received by a gps antenna) and determines a location solution. the gps processor may also be able to apply (and determine) differential gps corrections. gps receiver the combination of a gps antenna and a gps processor. gps time the length of the second is fixed and is determined by primary atomic frequency standards. leap-seconds are not used, as they are in utc. therefore, gps time and utc differ by a variable whole number of seconds. hdop horizontal dilution of precision. host system the device or instrument connected to the acutime 2000 smart antenna. the host system can be a pc, network equipment, or timing system, depending on the application. www.datasheet.co.kr datasheet pdf - http://www..net/ glossary- acutime 2000 synchronization kit user guide glossary how hand-over word. the word in the gps message that contains time synchronization information for the transfer from c/a to p-code. interface cable the interface cable allows data to flow between the acutime 2000 and the communication equipment. interference refers to the unwanted occurrences on communication channels that are a result of natural or man-made noises and signals, not properly a part of the signals being transmitted or received. integrated doppler a measurement of doppler shift frequency or phase over time. iode issue of data, ephemeris. part of the navigation data. it is the issue number of the ephemeris information. a new ephemeris is available usually on the hour. especially important for differential gps operation that the iode change is tracked at both the reference station and mobile stations. jamming interference (in either transmitting or receiving signals) caused by other radio signals at exactly or approximately the same frequency. masks see satellite masks . maximum pdop a measure of the maximum position dilution of precision (pdop) that is acceptable in order for the gps processor to determine a location solution (see pdop). navstar the name given to the gps satellites, built by rockwell international, which is an acronym formed from navigation system with time and ranging. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide glossary- glossary nmea national marine electronics association. an association that defines marine electronic interface standards for the purpose of serving the public interest. nmea 0183 message nmea 0183 is a standard for interfacing marine electronics navigational devices. the standard specifies the message format used to communicate with marine devices/ components. packet an "envelope" for data, which contains addresses and error checking information as well as the data itself. parity a scheme for detecting certain errors in data transmission. parity defines the condition (i.e., even or odd) of the number of items in a set (e.g., bits in a byte). pdop position dilution of precision. pdop is a unitless figure of merit that describes how an uncertainty in pseudo-range affects position solutions. pdop constellation switch a value, based on pdop, that defines when the gps receiver/processor should switch between 2-d and 3-d gps modes. the pdop constellation switch is only active when the gps mode of operation is set to auto. prn pseudo-random noise. each gps satellite generates its own distinctive prn code, which is modulated onto each carrier. the prn code serves as identification of the satellite, as a timing signal, and as a subcarrier for the navigation data. protocol a formal set of rules that describe a method of communication. the protocol governs the format and control of inputs and outputs. www.datasheet.co.kr datasheet pdf - http://www..net/ glossary-10 acutime 2000 synchronization kit user guide glossary pseudo-range a measure of the range from the gps antenna to a gps satellite. pseudo-range is obtained by multiplying the speed of light by the apparent transit time of the signal from the gps satellite. pseudo-range differs from actual range because the satellite and user clocks are offset from gps time and because of propagation delays and other errors. ram random-access memory. random-access memory memory in which information can be referred to in an arbitrary or random order. the contents of ram are lost when the system unit is turned off. range a term used to refer to the distance radio signals can travel before they must be received or repeated due to loss of signal strength, the curvature of the earth and the noise introduced because of moisture in the air surrounding the earth's surface. range rate the rate of change of range between the satellite and receiver. the range to a satellite changes due to satellite and observer motions. range rate is determined by measuring the doppler shift of the satellite beacon carrier. read-only memory memory whose contents can be read, but not changed. information is placed into rom only once. the contents of rom are not erased when the system unit's power is turned off. relative positioning the process of determining the vector distance between two points and the coordinates of one spot relative to another. this technique yields gps positions with greater precision than a single point positioning mode can. rise/set time the period during which a satellite is visible (i.e., has an elevation angle that is above the elevation mask). a satellite is said to "rise" when its elevation angle exceeds the mask and "set" when the elevation drops below the mask. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide glossary-11 glossary rom read-only memory. rtcm radio technical commission for maritime services. commission that recommends standards for differential gps services. rtcm recommended standards for differential gps service , prepared by rtcm special committee no. 104 (rtcm sc-104), defines a communication protocol for sending gps differential corrections from a differential reference station to remote gps receivers. satellite masks as satellites approach the horizon, their signals can become weak and distorted, preventing the receiver from gathering accurate data. satellite masks enable you to establish criteria for using satellite data in a position solution. there are three types of satellite masks: elevation, snr, and pdop. sa selective availability. this is the name of the policy and the implementation scheme by which unauthorized users of gps will have their accuracy limited to 100 meters 2d rms horizontal and 156 meters 2d rms vertical. sep spherical error probability. the radius of a sphere such that 50% of the position estimates will fall within the surface of the sphere. serial communication a system of sending bits of data on a single channel one after the other, rather than simultaneously. serial port a port in which each bit of information is brought in/out on a single channel. serial ports are designed for devices that receive data one bit at a time. signal-to-noise level gps signals with snrs that do not meet the mask criteria are considered unusable. www.datasheet.co.kr datasheet pdf - http://www..net/ glossary-12 acutime 2000 synchronization kit user guide glossary signal-to-noise ratio a measure of the relative power levels of a communication signal and noise on a data line. snr is expressed in decibels (db). snr signal-to-noise ratio. spread spectrum the received gps signal is a wide bandwidth, low-power signal (-160 dbw). this property results from modulating the l-band signal with a prn code in order to spread the signal energy over a bandwidth which is much greater than the signal information bandwidth. this is done to provide the ability to receive all satellites unambiguously and to provide some resistance to noise and multi-path. sps standard positioning service. refers to the gps as available to the authorized user. start bit in asynchronous transmission, the start bit is appended to the beginning of a character so that the bit sync and character sync can occur at the receiver equipment. stop bit in asynchronous transmission, the stop bit is appended to the end of each character. it sets the receiving hardware to a condition where it looks for the start bit of a new character. sv space vehicle (gps satellite). synchronous communication a method of sending digital data in which the bits come at fixed, rather than random, times and are synchronized to a clock. tsip trimble standard interface protocol. a binary/hex packet bi-directional protocol, also known as the tans protocol. used by a large number of trimble sensors. tsip is the subset of tans which is recognized by all trimble sensors except the 4000 series. the tsip protocol is defined in full in appendix a. www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide glossary-13 glossary ura satellite user range accuracy. the ura is sent by the satellite and is computed by the gps operators. it is a statistical indicator of the contribution of the apparent clock and ephemeris prediction accuracies to the ranging accuracies obtainable with a specific satellite based on historical data. utc universal coordinated time. uniform atomic time system/ standard that is maintained by the us naval observatory. utc defines the local solar mean time at the greenwich meridian. utc offset the difference between local time and utc (example: utc - est = 5 hours). www.datasheet.co.kr datasheet pdf - http://www..net/ glossary-14 acutime 2000 synchronization kit user guide glossary www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide index-1 index a abbreviations used in manual 1-xxiii acutime 2000 gps smart antenna 12-pin connector format 4-2 communicating with 2-4 connecting 2-2 connecting host system 3-5 connection diagram 2-3 connections 4-1 enclosure illustration 1-3 installation choosing location 3-1 routing and securing interface cable 3-4 installing 2-1, 3-1 interface cables and connectors 4-3 interface connector 4-2 mounting 3-3 overview 1-2 specifications d-1 start-up 5-1 almanac a-37, a-55 appendix f, theory of operation 1-xx, 5-1 appendix f, theory of operation. 5-1 audience 1-xix c cable delay compensation 5-9 cautions 1-xxiv choosing location for antenna 3-1 cold start e-3 command packets a-13 communicating with acutime 2000 2-4 timing receiver monitor 2-4 computer and power source connecting 2-3 connecting computer and power source 2-3 connecting host system 3-5 connection instructions 4-6 power 4-6 timing packet 4-7 timing pulse 4-6 connection diagram 2-3 coordinate systems e-7 nmea 0183 e-7 tsip e-7 d department of defense glossary-7 document conventions 1-xxiii dynamic limits e-8 e ecef a-27 electrical specifications d-3 elevation mask 5-2 www.datasheet.co.kr datasheet pdf - http://www..net/ index-2 acutime 2000 synchronization kit user guide environmental specifications d-2 event input 4-8 external event input 5-9 g garage search strategy e-5 getting started 2-1 glossary glossary-1 gps timing 5-12 h hae a-27 health of receiver a-43 health of satellite a-46 height above ellipsoid a-27 hot start e-5 i installation 3-1 interface and power connections 4-1 interface cable routing and securing 3-4 introduction 1-1 items required for installation 2-1 m main screen b-2 mounting the smart antenna 3-3 n nmea 0183 e-7 nmea 0183 message formats c-5 notes 1-xxiv o operation theory e-1 organization 1-xx other information 1-xxii overdetermined timing mode 5-5 p packet descriptions a-18 pdop mask 5-3 performance e-8 dynamic limits e-8 re-acquisition e-8 update rate e-8 performance specifications d-2 physical specifications d-1 pin-out descriptions 4-4 position accuracy e-6 selective availability e-6 power connection 4-6 pps output options 5-6 pps quantization error 5-6, 5-7 r raw measurement data a-35 re-acquisition e-8 reader comment form 1-5 report packets a-15 routing interface cable 3-4 s satellite acquisition e-3 www.datasheet.co.kr datasheet pdf - http://www..net/ acutime 2000 synchronization kit user guide index-3 cold start e-3 garage search strategy e-5 hot start e-5 warm start e-4 satellite masks 5-2 satellite signal levels a-45 scope 1-xix securing interface cable 3-4 selective availability e-6 self-survey mode 5-4 serial communication 5-10 serial port selection screen b-1 serial protocols d-4 snr mask 5-3 specifications d-1 electrical d-3 environmental d-2 performance d-2 physical d-1 serial protocols d-4 start-up 5-1 system architecture e-10 system operation overview 5-1 t technical assistance 1-xxii theory of operation e-1 timing packet serial connection 4-7 timing pulse connections 4-6 timing receiver monitor 2-4 timing receiver monitor screen serial port selection b-1 timing receiver monitor screens main b-2 tips 1-xxiv tracking codes 5-4 trimble standard interface protocol see tsip a-1 tsip e-7 command packets a-13 0x26, health request a-21 0x2b, initial position (latitude, longitude, altitude) command a-24 0x2f, utc parameters command a-25 0x3d, timing port configuration command a- 37 report packets a-15 0x4c, operating parameters report a-49 0x4e, gps time change acknowledgment a-50 0x57, information about last computed fix report a-54 0x59, satellite attributes database report a-60 0x5a, raw measurement data report a-61 0x5c, satellite tracking status report a-65 0x5f, eeprom segment status reports a-67 u update notes 1-xxii update rate e-8 w warm start e-4 world wide web (www) site 1-xxii www.datasheet.co.kr datasheet pdf - http://www..net/ index-4 acutime 2000 synchronization kit user guide www.datasheet.co.kr datasheet pdf - http://www..net/ reader comment form acutime 2000 synchronization kit user guide may 2002 p/n: 45005-00-eng revision c we appreciate your comments and suggestions for improving this publication. contributors of particularly helpful evaluations will receive a thank-you gift. i use the following trimble product_________ _______________________________________ for ___________________________________ _______________________________________ please circle a response for each of the statements below: 1 = strongly agree 2 = agree 3 = neutral 4 = disagree 5 = strongly disagree the manual is well organized. 1 2 3 4 5 i can find the information i want. 1 2 3 4 5 the information in the manual is accurate. 1 2 3 4 5 i can easily understand the instructions. 1 2 3 4 5 the manual contains enough examples. 1 2 3 4 5 the examples are appropriate and helpful. 1 2 3 4 5 the layout and format are attractive and useful. 1 2 3 4 5 the illustrations are clear and helpful. 1 2 3 4 5 the manual is: too long just right too short please answer the following questions: which sections do you use the most? _______ _______________________________________ what do you like best about the manual? ____ _______________________________________ _____________________________________ _______________________________________ what do you like least about the manual? ____ _______________________________________ _____________________________________ _______________________________________ optional name ________________________________ _______________________________________ company _____________________________ _______________________________________ address_______________________________ _______________________________________ _____________________________________ _______________________________________ telephone _____________________________ fax __________________________________ please mail to trimble navigation limited, 645 north mary avenue, p.o. box 3642, sunnyvale, ca 94088-3642. alternatively, email your comments and suggestions to readerfeedback@trimble.com. all comments and suggestions become the property of trimble navigation limited. www.datasheet.co.kr datasheet pdf - http://www..net/ www.datasheet.co.kr datasheet pdf - http://www..net/ |
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