GPS 18x TECHNICAL SPECIFICATIONS Garmin International, Inc. 1200 E.
© 2008–2011 Garmin Ltd. or its subsidiaries Garmin International, Inc 1200 East 151st Street, Olathe, Kansas 66062, USA Tel. 913/397.8200 or 800/800.1020 Fax 913/397.8282 Garmin (Europe) Ltd. Liberty House, Hounsdown Business Park Southampton, Hampshire, SO40 9LR UK Tel. +44 (0) 870.8501242 (outside the UK) 0808 2380000 (within the UK) Fax +44 (0) 870.8501251 Garmin Corporation No. 68, Zhangshu 2nd Road, Xizhi Dist. New Taipei City, 221, Taiwan (R.O.C.) Tel. 886/2.2642.9199 Fax 886/2.2642.
TABLE OF CONTENTS 1 Introduction ..............................................................................................................................1 1.1 Cautions........................................................................................................................................................... 1 1.2 Limited Warranty ............................................................................................................................................ 2 1.3 Overview ...
.2.8 4.2.9 4.2.10 4.2.11 4.2.12 4.2.13 4.2.14 4.2.15 4.2.16 Track Made Good and Ground Speed (VTG) ................................................................................................. 18 Geographic Position (GLL) ............................................................................................................................. 18 Estimated Error Information (PGRME) ..........................................................................................................
1 INTRODUCTION 1.1 CAUTIONS 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 18x is a precision electronic NAVigation AID (NAVAID), any NAVAID can be misused or misinterpreted, and therefore become unsafe. Use these products at your own risk. To reduce the risk, carefully review and understand all aspects of these Technical Specifications before using the GPS 18x.
1.2 LIMITED WARRANTY This Garmin product is warranted to be free from defects in materials or workmanship for one year from the date of purchase. Within this period, Garmin will, at its sole option, repair or replace any components that fail in normal use. Such repairs or replacement will be made at no charge to the customer for parts or labor, provided that the customer shall be responsible for any transportation cost.
1.3 OVERVIEW The GPS 18x series products include an embedded receiver and an antenna. Based on the proven technology found in other Garmin GPS receivers, the GPS 18x tracks multiple satellites at a time while providing fast time-to-first-fix, precise navigation updates (five times per second for the GPS 18x-5Hz, and once per second for the GPS 18x USB, 18x PC, and 18x LVC), and low power consumption.
1.5 GPS 18x SERIES There are several different versions of GPS 18x available. Refer below for a list of the three major divisions of the GPS 18x Series. 1.5.1 GPS 18x USB 1.5.2 GPS 18x PC The GPS 18x USB interfaces to a computer with an available USB port. Drivers are available for use on Windows computers. Macintosh and Linux drivers are not available from Garmin.
1.6 TECHNICAL SPECIFICATIONS Specifications are subject to change without notice. 1.6.1 Physical Characteristics 1.6.1.1 Size 61 mm (2.4 inches) in diameter and 19.5 mm (0.77 inches) in height 1.6.1.2 Weight • GPS 18x USB: 3.7 oz (105 g) • GPS 18x PC: 6.3 oz (180 g) • GPS 18x LVC-5m (5 meter cable): 5.6 oz (160 g) • GPS 18x-5Hz (5 meter cable): 5.8 oz (165 g) 1.6.1.3 Color Black 1.6.1.
1.6.2.5 Environmental Characteristics • Operating Temperature: -30°C to +80°C (-22°F to +176°F) • 1.6.3 Storage Temperature: -40°C to +90°C (-40°F to +194°F) GPS Performance 1.6.3.1 Receiver WAAS-enabled GPS receiver continuously tracks and uses multiple satellites to compute and update your position. 1.6.3.2 Acquisition Times • Reacquisition: Less than 2 seconds • Hot: Approx. 1 second (all data known) • Warm: Approx.
1.6.4.3 GPS 18x PC, GPS 18x LVC, & GPS 18x-5Hz Protocols • NMEA 0183 Version 2.0 or NMEA 0183 Version 2.30 (Version 2.0 is factory default, programmable by data field 7 of the PGRMC1 sentence described in section 4.1.4 Additional Sensor Configuration Information (PGRMC1). • Available NMEA 0183 output sentences include GPALM, GPGGA, GPGSA, GPGSV, GPRMC, GPVTG, GPGLL, PGRME, PGRMF, PGRMID, PGRMM, PGRMT, PGRMV, and PGRMB (Garmin proprietary sentences). See section 4.
2 GPSX 18x LVC & GPS 18x -5Hz WIRING AND PINOUTS The GPS 18x LVC/18x-5Hz interfaces to a serial port. The unit accepts TIA-232-F (RS-232) level inputs and transmits voltage levels from ground to the input voltage, TIA-232-F (RS-232) polarity. The GPS 18x LVC/18x-5Hz wires are terminated with a six-wire connector that is used by Garmin for testing purposes. You can remove this connector without voiding your warranty (see section 1.2 Limited Warranty). 2.
Figure 2. PDA Serial Port Interconnection Figure 3. Basic NMEA Device Interconnection 190-00879-08 GPS 18x Technical Specifications Page 9 Rev.
3 MECHANICAL CHARACTERISTICS & MOUNTING The central threaded recess accepts a metric M3 threaded bolt. The recess is approximately 4 mm deep (4.32 +/0.08 mm). The following drawings show example geometries for mounting hardware in case you wish to design your own custom mount. Figure 5 shows mounting geometry for a mount formed from steel sheet metal that is 1.15 mm thick. Figure 7 shows similar mounting geometry for mount formed from aluminum sheet metal that is 1.25 mm thick.
UNITS: MILLIMETERS Figure 5. GPS 18x Suction Cup Mount Center Hole Dimensions UNITS: MILLIMETERS Figure 6. GPS 18x Flush Mount Dimensions Figure 7. GPS 18x Flush Mount Center Hole Dimensions 190-00879-08 GPS 18x Technical Specifications Page 11 Rev.
4 GPS 18x PC, GPS 18x LVC, & GPS 18x-5Hz SOFTWARE INTERFACE The interface protocol design of the GPS 18x PC, LVC, and GPS 18x-5Hz products is based on the National Marine Electronics Association’s NMEA 0183 ASCII interface specification. This standard is fully defined in NMEA 0183, Version 2.30. Copies may be obtained from NMEA at www.nmea.org.
4.1.2 Sensor Initialization Information (PGRMI) The $PGRMI sentence provides information used to initialize the GPS sensor’s set position and time used for satellite acquisition. Receipt of this sentence by the GPS sensor 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.
4.1.4 Additional Sensor Configuration Information (PGRMC1) The $PGRMC1 sentence provides additional information used to configure the GPS sensor operation. Configuration parameters are stored in non-volatile memory and retained between power cycles. The GPS sensor will echo this sentence upon its receipt if no errors are detected. If an error is detected, the echoed PGRMC1 sentence will contain the current default values. Current default values can also be obtained by sending $PGRMC1E to the GPS sensor.
4.2 TRANSMITTED NMEA 0183 SENTENCES The subsequent paragraphs define the sentences that can be transmitted by the GPS 18x PC and LVC. 4.2.1 Sentence Transmission Rate Sentences are transmitted with respect to the user selected baud rate. The GPS sensor will transmit each sentence (except where noted in particular transmitted sentence descriptions) at a periodic rate based on the user selected baud rate and user selected output sentences. The GPS sensor will transmit the selected sentences contiguously.
4.2.2 Transmitted Time The GPS sensor outputs Coordinated Universal Time (UTC) date and time of day in the transmitted sentences. Before the initial position fix, the on-board clock provides the date and time of day. After the initial position fix, the date and time of day are calculated using GPS satellite information and are synchronized with the measurement pulse output. The GPS 18x-5Hz outputs a UTC with a tenths-of-a-second precision: 123456.8, for example.
4.2.4 Global Positioning System Fix Data (GGA) $GPGGA,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,M,<10>,M,<11>,<12>*hh <1> <2> <3> <4> <5> <6> <7> <8> <9> <10> <11> <12> 4.2.5 UTC time of position fix, hhmmss format for GPS 18x PC or LVC; hhmmss.s format for GPS 18x-5Hz Latitude, ddmm.mmmm format for GPS 18x PC/LVC; ddmm.mmmmm for GPS 18x-5Hz (leading zeros will be transmitted) Latitude hemisphere, N or S Longitude, dddmm.mmmm format for GPS 18x PC/LVC; dddmm.
4.2.7 Recommended Minimum Specific GPS/TRANSIT Data (RMC) $GPRMC,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,<12>*hh <1> <2> <3> <4> <5> <6> <7> <8> <9> <10> <11> <12> 4.2.8 UTC time of position fix, hhmmss format for GPS 18x PC/LVC; hhmmss.s format for GPS 18x-5Hz Status, A = Valid position, V = NAV receiver warning Latitude, ddmm.mmmm format for GPS 18x PC/LVC; ddmm.mmmmm format for GPS 18x5Hz (leading zeros must be transmitted) Latitude hemisphere, N or S Longitude, dddmm.
4.2.11 GPS Fix Data Sentence (PGRMF) $PGRMF,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,<12>,<13>,<14>,<15>*hh <1> <2> <3> <4> <5> <6> <7> <8> <9> <10> <11> <12> <13> <14> <15> GPS week number (0 to 1023) GPS seconds (0 to 604799) UTC date of position fix, ddmmyy format UTC time of position fix, hhmmss format for GPS 18x PC/LVC; hhmmss.s format for GPS 18x-5Hz GPS leap second count Latitude, ddmm.mmmm format for GPS 18x PC/LVC; ddmm.
4.2.15 3D Velocity Information (PGRMV) $PGRMV,<1>,<2>,<3>*hh <1> <2> <3> True east velocity, -514.4 to 514.4 meters/second for GPS 18x PC/LVC; -514.44 to 514.44 for GPS 18x-5Hz True north velocity, -514.4 to 514.4 meters/second for GPS 18x PC/LVC; -514.44 to 514.44 for GPS 18x-5Hz Up velocity, -999.9 to 999.9 meters/second for GPS 18x PC/LVC; -999.99 to 999.99 for GPS 18x-5Hz 4.2.16 DGPS Beacon Information (PGRMB) Note: The GPS 18x products do not support PGRMB at this time.
The accuracy of the five-pulse-per-second output is maintained only while the GPS 18x-5Hz can compute a valid position fix. To obtain the most accurate results, the five-pulse-per-second output should be calibrated against a local time reference to compensate for cable and internal receiver delays and the local time bias. The default pulse width is 100 ms, however; it may be programmed in 20 ms increments between 20 ms and 180 ms as described in $PGRMC section 4.1.
APPENDIX A: EARTH DATUM LIST The following is a list of the Garmin GPS 18x Earth datum indices and the corresponding earth datum name (including the area of application): 0 ADINDAN–Ethiopia, Mali, Senegal, Sudan 9 AUSTRALIAN GEODETIC 1984–Australia, Tasmania Island 10 ASTRO DOS 71/4–St.
44 KERTAU 1948–West Malaysia, Singapore 45 L.C.
83 PROVISIONAL SOUTH AMERICAN 1956–Bolivia, Chile, Colombia, Ecuador, Guyana, Peru, Venezuela 84 SOUTH AMERICAN 1969–Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Venezuela, Trinidad and Tobago 85 SOUTH ASIA–Singapore 86 PROVISIONAL SOUTH CHILEAN 1963–South Chile 87 SANTO (DOS)–Espirito Santo Island 88 SAO BRAZ–Sao Miguel, Santa Maria Islands (Azores) 89 SAPPER HILL 1943–East Falkland Island 90 SCHWARZECK–Namibia 91 SOUTHEAST BASE–Porto Santo and Madeira Isla
APPENDIX B: GARMIN BINARY OUTPUT FORMAT In Binary Output mode, GPS 18x series products will transmit packets once per second. The record contains primarily post-process information such as position and velocity information. For the GPS 18x PC, GPS 18x LVC, and GPS 18x-5Hz the record is sent at a default baud rate of 4800 baud, 8 data bits, and no parity.
Satellite Data Record The satellite data has a record ID of 0x72 with 84 (0x54) data bytes. The data bytes contain data for 12 satellites as described below.
Position Record The Position Record has a record identifier of typedef struct { float alt; float epe; float eph; float epv; int fix; double gps_tow; double lat; double lon; float lon_vel; float lat_vel; float alt_vel; float msl_hght; int leap_sec; long grmn_days; } cpo_pvt_data; alt epe eph epv fix Ellipsoid altitude (meters) Estimated position error (meters) Position error, horizontal (meters) Position error, vertical (meters) 0 = no fix; 1 = no fix; 2 = 2D; 3 = 3D; 4 = 2D differential; 5 = 3D differentia
DLE and ETX bytes: Sample C code to receive the two records should filter DLE and ETX bytes as described below: typedef enum { DAT, DLE, ETX } rx_state_type; /* Declare and initialize static variables */ static char in_que[ 256 ]; static int in_que_ptr = 0; static rx_state_type rx_state = DAT; . . .
APPENDIX C: CHANGING THE BAUD RATE IN GARMIN MODE In certain cases, you may need to change the default baud rate of your Garmin GPS receiver while in Garmin mode. Follow these steps to temporarily change the baud rate. Refer to the Garmin Device Interface Specification found in the Garmin Device Interface SDK for details on how to form and parse Garmin packets. At the time of this printing, these specs are available from the technical suppport section of our Web site: www.garmin.com/support/commProtocol.
APPENDIX D: GPS 18x PC/ LVC/18x-5HZ & WINDOWS SERIAL MOUSE ISSUE Problem: It is possible for Windows to incorrectly interpret the NMEA 0183 output of the GPS 18x PC as the output of a Microsoft Serial BallPoint Mouse. When that happens, Windows loads drivers for the Serial BallPoint Mouse. This causes the cursor to move erratically about the display, clicking, right clicking, double clicking, dragging and dropping displayed items as it goes.
4. Select the serial port to which the GPS 18x is connected. Select Auto to have the program automatically determine the baud rate, or select Manual to manually select the baud rate of the GPS 18x. Click OK when done. 5. Click the Connect icon , or select Comm > Connect to connect to the GPS 18x. 6. To view the current programming of the GPS 18x, select Config > Get Configuration from GPS (or press the F8 key).
APPENDIX E: SENSOR CONFIGURATION SOFTWARE The Garmin Sensor Configuration Software (SNSRCFG.exe) configures the GPS sensors based on user-selected parameters. Some application features include the ability to download GPS sensor configuration, maintain different configurations in files, and perform GPS sensor configurations quickly with the use of one function key. This section provides a brief overview of the Sensor Configuration Software.
Menus File Menu The File Menu allows you to open, save, and print sensor configurations. The items in the File Menu work like most Windows-based programs. Comm Menu The Comm (Communication) Menu allows you to set the port number and baud rate, as well as connect to the sensor and disconnect from the sensor. Setup: Opens the Comm Setup window. Select the serial port to which the sensor is connected from the drop-down list.
Get Configuration From GPS (F8): Retrieves the current programming from the sensor. The programming is then displayed in the Main Interface window. Send Configuration To GPS (F9): Sends your updated configuration programming to the sensor. Switch to NMEA Mode (F10): Switches the unit to NMEA Mode. The sensor must be in NMEA Mode when connected to this software. Switch to Garmin Mode (F11): Switches the unit to Garmin Mode.
