GPS 35 LP TracPak TM GPS SMART ANTENNA TECHNICAL SPECIFICATION Models: GPS35-LVC GPS35-LVS GPS35-HVS ____________________________________________________________ GARMIN · 1200 E.
© 2000 GARMIN Corporation, 1200 E. 151st Street, Olathe, KS 66062 All rights reserved. No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying and recording, for any purpose without the express written permission of GARMIN. Information in this document is subject to change without notice.
CAUTION The GPS system is operated by the government of the United States which is solely responsible for its accuracy and maintenance. Although the GPS 35LP is a precision electronic NAVigation AID (NAVAID), any NAVAID can be misused or misinterpreted, and therefore become unsafe. Use the GPS 35LP at your own risk. To reduce the risk, carefully review and understand all aspects of this Technical Manual before using the GPS 35LP.
TABLE OF CONTENTS 1. Introduction 1.1 Overview 1.2 Features 1.3 Naming Conventions 1.4 Technical Specifications 1.5 Application 1 1 1 2 2 4 2. Operational Characteristics 2.1 Self Test 2.2 Initialization 2.3 Navigation 2.4 Satellite Data Collection 5 5 5 5 6 3. Hardware Interface 3.1 Mechanical Dimensions 3.2 Mounting Configurations and Options 3.3 Connection Wiring Description 8 8 9 13 4. Software Interface 4.1 NMEA Received Sentences 4.2 NMEA Transmitted Sentences 4.3 Baud Rate Selection 4.
SECTION 1 INTRODUCTION 1.1 OVERVIEW The GARMIN GPS 35LP is a complete GPS receiver, including an embedded antenna, designed for a broad spectrum of OEM (Original Equipment Manufacturer) system applications. Based on the proven technology found in other GARMIN 12 channel GPS receivers, the GPS 35LP will track up to 12 satellites at a time while providing fast time-to-first-fix, one second navigation updates and low power consumption.
10) Binary Format Phase Data Output on TXD2 11) Flexible input voltage levels of 3.6Vdc to 6.0Vdc with overvoltage protection in the -LVx versions, and 6.0Vdc to 40Vdc in the -HVx versions. 12) FLASH based program memory. New software revisions upgradeable through serial interface. 1.3 Naming Conventions The GPS 35LP Series TrackPack™ receivers are delineated with a three letter extension to designate the operating voltage range and the serial data voltage specification.
2) Input current: 120 mA typical 140 mA max -LVx versions, 20 mA while in power down. 870mW typical 1000mW max -HVx version, 300uA while in power down. 3) Backup power: 3V Rechargeable Lithium cell battery, up to 6 month charge. 4) Power Down Input: 2.7V threshold 1.4.4 Performance 1) Tracks up to 12 satellites (up to 11 with PPS active) 2) Update rate: 1 second 3) Acquisition time - 15 seconds warm (all data known) - 45 seconds cold (initial position, time and almanac known, ephemeris unknown) - 5.
4) One-pulse-per-second timing output 5) Binary Format Phase Data 1.5 APPLICATION Fig.
SECTION 2 OPERATIONAL CHARACTERISTICS This section describes the basic operational characteristics of the GPS 35LP. Additional information regarding input and output specifications are contained in Section 4. 2.1 SELF TEST After input power has been applied to the GPS 35LP and periodically thereafter, the unit will perform critical self test functions and report the results over the output channel(s).
1) Latitude/longitude/altitude 2) Velocity 3) Date/time 4) Error estimates 5) Satellite and receiver status Normally the GPS 35LP will select the optimal navigation mode (2D or 3D) based on available satellites and geometry considerations. The host system, at its option, may command the GPS 35LP to choose a specific mode of navigation, such as 2D.
minutes to calculate a navigation solution. AutoLocate™, unlike search the sky, does not require that the receiver continue to operate after a fix has been obtained.
SECTION 3 HARDWARE INTERFACE 3.1 MECHANICAL DIMENSIONS The GPS 35LP is a complete GPS receiver including antenna in a uniquely styled waterproof package. 3.1.1 GPS 35 Dimensions (General tolerance ± 0.50mm) Fig.
3.2 MOUNTING CONFIGURATIONS AND OPTIONS The following mounting options are available for the GPS 35LP. Mounting is user configurable. 3.2.1 Magnetic Mount The magnetic mount provides a firm, removable mounting attachment to any ferrous metal surface. Fig.
3.2.2 Trunk Lip Mount The trunk lip mount provides a semi-permanent attachment to the trunk lip of most automobiles. Fig.
3.2.3 Suction Cup Mount The suction cup bracket provides a removable mounting surface attached to the inside of a vehicle's windshield. Fig.
3.2.4 Flange Mount The flange mount allows for a permanent installation on a flat surface. This mounting configuration is ideal in applications in which the far side of the mounting surface is inaccessible. Fig.
3.3 CONNECTION WIRING DESCRIPTION The GPS 35LP features a stripped and pre-tinned cable assembly for connection flexibility. The following is a functional description of each wire in the cable assembly. Red: Vin - Regulated +3.6V to +6V, 150 mA (maximum) in the -LVx versions. Typical operating current is 120 mA. Transients and overvoltages are protected by an internal 6.8V transient zener diode and a positive temperature coefficient thermistor. With voltages greater than 6.
Software Interface The GPS 35LP interface protocol design is based on the National Marine Electronics Association’s NMEA 0183 ASCII interface specification, which is fully defined in “NMEA 0183, Version 2.0” (copies may be obtained from NMEA, P.O. Box 50040, Mobile, AL, 36605, USA) and the Radio Technical Commission for Maritime Services’ “RTCM Recommended Standards For Differential Navstar GPS Service, Version 2.1, RTCM Special Committee No. 104” (copies may be obtained from RTCM, P.O.
4.1.2 Sensor Initialization Information (PGRMI) The $PGRMI sentence provides information used to initialize the sensor board set position and time used for satellite acquisition. Receipt of this sentence by the board set causes the software to restart the satellite acquisition process. If there are no errors in the sentence, it will be echoed upon receipt. If an error is detected, the echoed PGRMI sentence will contain the current default values.
All configuration changes take effect after receipt of a valid value except baud rate and PPS mode. Baud rate and PPS mode changes take effect on the next power cycle or an external reset event. 4.1.4 Additional Sensor Configuration Information (PGRMC1) The $PGRMC1 sentence provides additional information used to configure the sensor board operation. Configuration parameters are stored in non-volatile memory and retained between power cycles.
4) $PGRMO,GPALM,1 will cause the sensor board to transmit all stored almanac information. All other NMEA sentence transmission will be temporarily suspended. 4.1.6 Tune DGPS Beacon Receiver (PSLIB) The $PSLIB sentence provides the ability to tune a GARMIN GBR-21 or equivalent beacon receiver. $PSLIB,<1>,<2>*hh <1> <2> Beacon tune frequency, 0.0, 283.5 – 325.0 kHz in 0.
4.2 NMEA Transmitted Sentences The subsequent paragraphs define the sentences which can be transmitted on TXD1 by the GPS 35LP receivers. 4.2.1 Sentence Transmission Rate Sentences are transmitted with respect to the user selected baud rate. Regardless of the selected baud rate, the information transmitted by the GPS 35LP is referenced to the one-pulse-per-second output pulse immediately preceding the GPRMC sentence.
4.2.2 Transmitted Time The GPS 35LP receivers output UTC (Coordinated Universal Time) date and time of day in the transmitted sentences. Prior to the initial position fix, the date and time of day are provided by the onboard clock. After the initial position fix, the date and time of day are calculated using GPS satellite information and are synchronized with the one-pulse-per-second output.
<6> <7> <8> <9> <10> <11> <12> 4.2.5 GPS quality indication, 0 = fix not available, 1 = Non-differential GPS fix available, 2 = Differential GPS (DGPS) fix available 6 = Estimated Number of satellites in use, 00 to 12 (leading zeros will be transmitted) Horizontal dilution of precision, 0.5 to 99.9 Antenna height above/below mean sea level, -9999.9 to 99999.9 meters Geoidal height, -999.9 to 9999.
<12> Mode indicator (only output if NMEA 2.30 active), A = Autonomous, D = Differential, E = Estimated, N = Data not valid 4.2.8 Track Made Good and Ground Speed with GPS Talker ID (VTG) The GPVTG sentence reports track and velocity information with a checksum: $GPVTG,<1>,T,<2>,M,<3>,N,<4>,K,<5>*hh <1> True course over ground, 000 to 359 degrees (leading zeros will be transmitted) <2> Magnetic course over ground, 000 to 359 degrees (leading zeros will be transmitted) <3> Speed over ground, 000.
$PGRMF,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,<12>,<13>,<14>,<15>*hh <1> GPS week number (0 - 1023) <2> GPS seconds (0 - 604799) <3> UTC date of position fix, ddmmyy format <4> UTC time of position fix, hhmmss format <5> GPS leap second count <6> Latitude, ddmm.mmmm format (leading zeros will be transmitted) <7> Latitude hemisphere, N or S <8> Longitude, dddmm.
4.3 Baud Rate Selection Baud rate selection can be performed by sending the appropriate configuration sentence to the sensor board as described in the NMEA input sentences selection. (Section 4.1) 4.4 One-Pulse-Per-Second Output The highly accurate one-pulse-per-second output is provided for applications requiring precise timing measurements. The signal is generated after the initial position fix has been calculated and continues until power down.
Appendix A Earth Datums The following is a list of the GARMIN GPS 35LP earth datum indexes and the corresponding earth datum name (including the area of application): 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 ADINDAN - Ethiopia, Mali, Senegal, Sudan AFGOOYE - Somalia AIN EL ABD 1970 - Bahrain Island, Saudi Arabia ANNA 1 ASTRO 1965 - Cocos Island ARC 1950 - Botswana, Lesotho, Malawi, Swaziland, Zaire, Zambia, Zimbabwe ARC 1960 - Kenya
42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 KANDAWALA - Sri Lanka KERGUELEN ISLAND - Kerguelen Island KERTAU 1948 - West Malaysia, Singapore L.C.
91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 SOUTHEAST BASE - Porto Santo and Madeira Islands SOUTHWEST BASE - Faial, Graciosa, Pico, Sao Jorge, and Terceira Islands (Azores) TIMBALAI 1948 - Brunei and East Malaysia (Sarawak and Sabah) TOKYO - Japan, Korea, Okinawa TRISTAN ASTRO 1968 - Tristan da Cunha User defined earth datum VITI LEVU 1916 - Viti Levu Island (Fiji Islands) WAKE-ENIWETOK 1960 - Marshall Islands WORLD GEODETIC SYSTEM 1972 WORLD GEODETIC SYSTEM 1984 ZANDERIJ - Surinam CH-1903
Appendix B GPS 35LP Evaluation Kits GPS 35LP evaluation materials kit (part number 010-10186-00) is available from Garmin International. This kit includes two DB-9 connectors with solder pots, various mounting brackets, hookup wire, technical specification, and software to monitor the GPS 35LP outputs and configure the receiver. To install the evaluation and configuration software run the program, setup, by using the FILE - RUN command in Windows. NMEAVWR.EXE The NMEAVWR.
GPS25PM.EXE The Garmin Phase Monitor Program, GPS25PM.EXE, provides the following functions: - Display and log phase data output from TXD2 - Upload almanac, position, and time information via RXD2 - Download almanc and ephemeris information upon command GPS25PM.EXE can be invoked from a DOS prompt: gps25pm.
Appendix C Phase Output Data Binary Format Two records are transmitted once per second by the GPS 35LP. One record contains primarily postprocess information such as position and velocity information. The second record contains receiver measurement information. The records are sent at a default baud rate of 9600 baud, 8 bits, no parity. Records begin with a delimiter byte (10 hex). The second byte identifies the record type (28 hex for a position record, 29 hex for a receiver measurement).
lat lon lon_vel lat_vel alt_vel Latitude (rad) Longitude (rad) Longitude velocity (mt/sec) Latitude velocity (mt/sec) Altitude velocity (mt/sec) Receiver Measurement Record - 0x10 - 0x29 - 0xE2 - cpo_rcv_type - one byte chksum - 0x10 - 0x03 typedef struct { unsigned long double unsigned int char unsigned char char char } cpo_rcv_sv_type; typedef struct { double int cpo_rcv_sv_type } cpo_rcv_type; rcvr_tow rcvr_wn cycles pr phase slp_dtct snr_dbhz svid valid (dle is first byte) (receiver record identifier
dle and etx bytes: Software written to receive the two records should filter dle and etx bytes as described below: typedef enum { dat, dle, etx } rx_state_type; char int rx_state_type in_que[256]; in_que_ptr = 0; rx_state = dat; void add_to_que( char data ) { #define dle_byte 0x10 #define etx_byte 0x03 if (rx_state == dat) { if (data == dle_byte) { rx_state = dle; } else { in_que[ in_que_ptr++ ] = data; } } else if (rx_state == dle) { if (data == etx_byte) { rx_state = etx; } else { rx_state = dat; in_que
GARMIN Phase Monitor Program - gps25pm.exe Command Line Arguments default: /com1 /b:9600 - selects which PC serial port to use for communication - com1, com2 (com1 default). - selects the baud rate - 1200, 2400, 4800, or 9600 (9600 default) Description: GPS25PM.EXE is designed to interface with a Garmin GPS 25 XL or GPS 25LP sensor boards and the GPS 35LP sensors. The program will perform the following functions: - display and log phase data output by GPS sensors.
The bottom section contains program messages. Upload and download status messages will appear here as well as any program error messages. Commands: D - Download Almanac: The GPS25 sensor will be sent a command to download almanac information. GPS25PM.EXE will create the file ALMANAC.DAT and locate it the current working directory. If an ALMANAC.DAT exists in the current directory it will be over-written. U - Upload Almanac: The ALMANAC.
File Formats ALMANAC.DAT Example almanac entry: **** Week 794 almanac for PRN-01 ************ ID: 01 Health: 000 Eccentricity: 3.414630890E-003 Time of Applicability(s): 380928.0000 Orbital Inclination(rad): 9.549833536E-001 Rate of Right Ascen(r/s): -7.771752131E-009 SQRT(A) (m^1/2): 5153.589843 Right Ascen at TOA(rad): 8.032501489E-002 Argument of Perigee(rad): -1.308424592E+000 Mean Anom(rad): 2.045822620E+000 Af0(s): 9.536743164E-007 Af1(s/s): 8.
Ephemeris Record - 0x10 (dle is first byte) - 0x2A (ephemeris record identifier) - 0x74 (size of data) - eph_type (see description below) - one byte chksum (the addition of bytes between the delimiters should equal 0) - 0x10 (dle) - 0x03 (etx) typedef struct { char svid; int wn; float toc; float toe; float af0; float af1; float af2; float ura; double e; double sqrta; double dn; double m0; double w; double omg0; double i0; float odot; float idot; float cus; float cuc; float cis; float cic; float crs; float c
TIM time_of_week week_number RCV svid snr (T)rack/(C)ycle_slip phase pseudo_range cycles PVT time lat lon alt lat_vel lon_vel alt_vel epe eph epv TIM 235537.99855650 794 RCV 18 50 T 120.2 19964528.44 2068193 RCV 29 50 T 133.2 20364313.25 1950557 RCV 28 45 T 176.5 21135153.13 2069992 RCV 19 47 T 145.2 21190271.83 2182643 RCV 31 45 T 75.8 21240354.20 2216421 RCV 22 42 T 195.1 22849183.41 1855826 RCV 27 36 T 155.2 24234175.55 2230462 RCV 14 39 T 202.3 25147694.34 1845263 PVT 235537.99999842 38.9499588 94.
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