Garmin 18x-5Hz, 18 USB, 18 5Hz, 18 Technical Specification

GPS 18
TECHNICAL
SPECIFICATIONS



Garmin International, Inc.

1200 E. 151st Street

Olathe, KS 66062 USA

190-00307-00, Revision D

June 2005

GPS 18 Technical Specifications (190-00307-00 ) Rev. D

© Copyright 2004–2005
Garmin Ltd. or its subsidiaries
All Rights Reserved
Except as expressly provided below, no part of this manual may be reproduced, copied, transmitted,

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written consent of Garmin. Garmin hereby grants permission to download a single copy of this
manual and of any revision to this manual onto a hard drive or other electronic storage medium to be
viewed and to print one copy of this manual or of any revision hereto, provided that such electronic or
printed copy of this manual or revision must contain the complete text of this copyright notice and
provided further that any unauthorized commercial distribution of this manual or any revision hereto
is strictly prohibited.

Information in this document is subject to change without notice. Garmin reserves the right to change
or improve its products and to make changes in the content without obligation to notify any person or
organization of such changes or improvements.

Garmin International, Inc.
1200 East 151st Street,
Olathe, Kansas 66062, U.S.A.
Tel. [phone] or 800/800.1020
Fax [phone]

Garmin (Europe) Ltd.
Unit 5, The Quadrangle, Abbey Park Industrial Estate,
Romsey, SO51 9DL, U.K.
Tel. [phone]
Fax [phone]

Garmin Corporation
No. 68, Jangshu 2nd Road,
Shijr, Taipei County, Taiwan
Tel. [phone]
Fax [phone]

Web site address: www.garmin.com

RECORD OF REVISIONS

Revision Revision

Date

A 4/5/04 Initial Release -­B 6/7/04 Revise to include PGRMO 26125
C 5/24/05 Add GPS 18 LVC-5m and GPS 18-5Hz 31279
D 6/6/05 Add 38400 baud to field 10 of PGRMC sentence 31511

Description ECO #

GPS 18 Technical Specifications (190-00307-00 ) Rev. D

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TABLE OF CONTENTS

1 Introduction..................................................................................................................1

1.1 Cautions ............................................................................................................................................1

1.2 Limited Warranty..............................................................................................................................2

1.3 Features.............................................................................................................................................3

1.4 GPS 18 Series....................................................................................................................................4

1.4.1 GPS 18 USB...................................................................................................................................... 4

1.4.2 GPS 18 PC ........................................................................................................................................ 4

1.4.3 GPS 18 LVC, GPS 18 LVC-5m, and GPS 18-5Hz........................................................................... 4

1.5 Technical Specifications ...................................................................................................................5

1.5.1 Physical Characteristics..................................................................................................................... 5

1.5.1.1 Size.................................................................................................................................... 5

1.5.1.2 Weight............................................................................................................................... 5

1.5.1.3 Color.................................................................................................................................. 5

1.5.1.4 Case Material..................................................................................................................... 5

1.5.1.5 Cable Length..................................................................................................................... 5

1.5.2 Electrical Characteristics................................................................................................................... 5

1.5.2.1 Input Voltage ........................................................................................................... .......... 5

1.5.2.2 Input Current ..................................................................................................................... 5

1.5.2.3 CMOS Serial Output Levels.............................................................................................. 5

1.5.2.4 GPS Receiver Sensitivity .................................................................................................. 6

1.5.3 Environmental Characteristics........................................................................................................... 6

1.5.4 GPS Performance.............................................................................................................................. 6

1.5.4.1 Receiver............................................................................................................................. 6

1.5.4.2 Acquisition Times ............................................................................................................. 6

1.5.4.3 Update Rate....................................................................................................................... 6

1.5.4.4 Accuracy ........................................................................................................................... 6

1.5.5 Interfaces........................................................................................................................................... 7

1.5.5.1 GPS 18 Electrical Characteristics...................................................................................... 7

1.5.5.2 Garmin Interface and Garmin USB Protocol..................................................................... 7

1.5.5.3 GPS 18 PC, GPS 18 LVC, & GPS 18-5Hz Protocols........................................................ 7

1.5.5.4 Measurement Pulse Output (GPS 18 LVC & GPS 18-5Hz only)...................................... 7

2 GPS 18 LVC & GPS 18-5Hz Wiring and Pinouts ....................................................8

2.1 GPS 18 LVC & GPS 18-5Hz Pinout.................................................................................................8

2.2 GPS 18 LVC & GPS 18-5Hz Wiring Diagrams...............................................................................8

3 Mechanical Characteristics & Mounting.................................................................10

4 GPS 18 PC, GPS 18 LVC, & GPS 18-5Hz Software Interface..............................12

4.1 Received NMEA 0183 Sentences...................................................................................................12

4.1.1 Almanac Information (ALM) ...........................................................................................................12

4.1.2 Sensor Initialization Information (PGRMI)......................................................................................13

4.1.3 Sensor Configuration Information (PGRMC)..................................................................................13

4.1.4 Additional Sensor Configuration Information (PGRMC1) ..............................................................14

4.1.5 Output Sentence Enable/Disable (PGRMO).....................................................................................14

4.2 Transmitted NMEA 0183 Sentences...............................................................................................15

4.2.1 Sentence Transmission Rate.............................................................................................................15

4.2.2 Transmitted Time.............................................................................................................................16

4.2.3 Global Positioning System Almanac Data (ALM) ...........................................................................16

4.2.4 Global Positioning System Fix Data (GGA)....................................................................................17

4.2.5 GPS DOP and Active Satellites (GSA)............................................................................................17

4.2.6 GPS Satellites in View (GSV)..........................................................................................................17

4.2.7 Recommended Minimum Specific GPS/TRANSIT Data (RMC)....................................................18

4.2.8 Track Made Good and Ground Speed (VTG) ..................................................................................18

GPS 18 Technical Specifications (190-00307-00 ) Rev. D

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4.2.9 Geographic Position (GLL)..............................................................................................................18

4.2.10 Estimated Error Information (PGRME)...........................................................................................19

4.2.11 GPS Fix Data Sentence (PGRMF) ...................................................................................................19

4.2.12 Sensor Status Information (PGRMT)...............................................................................................19

4.2.13 3D Velocity Information (PGRMV).................................................................................................19

4.2.14 DGPS Beacon Information (PGRMB).............................................................................................20

4.3 Baud Rate Selection........................................................................................................................20

4.4 Measurement Pulse Output (GPS 18 LVC & 18-5Hz only) ...........................................................20

4.4.1 One-Pulse-Per-Second (PPS) Output (GPS 18 LVC Only)..............................................................20

4.4.2 Five-Pulse-Per-Second Output (GPS 18-5Hz Only).........................................................................20

Appendix A: Earth Datum List......................................................................................21

Appendix B: Binary Phase Output Format...................................................................24

Appendix C: Changing the Baud Rate in Garmin Mode.............................................29

Appendix D: GPS 18 PC/ LVC/18-5Hz & Windows Serial Mouse Issue...................30

Appendix E: Sensor Configuration Software................................................................32

Downloading the Sensor Configuration Software............................................................................................32

Selecting a Model.............................................................................................................................................32

Connecting to the Sensor .................................................................................................................................32

File Menu.........................................................................................................................................................33

Comm Menu....................................................................................................................................................33

Config Menu....................................................................................................................................................33

View Menu ......................................................................................................................................................34

Help Menu .......................................................................................................................................................34

LIST OF TABLES AND FIGURES

Table 1: GPS 18 LVC & GPS 18-5Hz Wire Pinout....................................................................................... 8

Figure 1: Computer Serial Port Interconnection............................................................................................. 8

Figure 2. PDA Serial Port Interconnection..................................................................................................... 9

Figure 3. Basic NMEA Device Interconnection............................................................................................. 9

Figure 4a. GPS 18 Bottom Case Dimensions, Under Mold ......................................................................... 10

Figure 4b. GPS 18 Bottom Case, Outside of Casing.................................................................................... 10

Figure 5. GPS 18 Suction Cup Mount Center Hole Dimensions.................................................................. 11

Figure 6. GPS 18 Flush Mount Dimensions................................................................................................. 11

Figure 7. GPS 18 Flush Mount Center Hole Dimensions.............................................................................11

Table 2: NMEA 0183 Output Sentence Order and Size...............................................................................15

Table 3: Characters per Second for Available Baud Rates........................................................................... 15

GPS 18 Technical Specifications (190-00307-00 ) Rev. D

Page iii

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 18 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 18. When in actual use, carefully compare indications from the GPS to all available
navigation sources including the information from other NAVAIDs, visual sightings, charts, etc. For safety,
always resolve any discrepancies before continuing na vi gat i on.

FCC

Compliance

The GPS 18 complies with Part 15 of the FCC interference limits for Class B digital devices FOR HOME
OR OFFICE USE. These limits are designed to provide reasonable protection against harmful interference
in a residential installation, and are more stringent than “ou tdoor” r e quirements.

Operation of this device is subject to the following conditions: (1) This device may not cause harmful
interference, and (2) this device must accept any interference received, including interference that may
cause undesired operation.

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 communications. 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 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.

The GPS 18 does not contain any user-serviceable parts. Unauthorized repairs or modifications could result
in permanent damage to the equipment, and void your warranty and your authority to operate this device
under Part 15 regulations.

GPS 18 Technical Specifications (190-00307-00 ) Rev. D

Page 1

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. This warranty does not
cover failures due to abuse, misuse, accident or unauthorized alteration or repairs.

THE WARRANTIES AND REMEDIES CONTAINED HEREIN ARE EXCLUSIVE AND IN LIEU OF
ALL OTHER WARRANTIES EXPRESS OR IMPLIED OR STATUTORY, INCL UDI N G AN Y
LIABILITY ARISING UNDER ANY WARRANTY OF MERCHANT ABILITY OR FITNESS FOR A
PARTICULAR PURPOSE, STATUTORY OR OTHERWISE. THIS WARRANTY GIVES YOU
SPECIFIC LEGAL RIGHTS, WHICH MAY VARY FROM STATE TO STATE.

IN NO EVENT SHALL GARMIN BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT OR
CONSEQUENTIAL DAMAGES, WHETHER RESULTING FROM THE USE, MISUSE, OR
INABILITY TO USE THIS PRODUCT OR FROM DEFECTS IN THE PRODUCT. Some states do not
allow the exclusion of incidental or consequential damages, so the above limitations may not apply to you.

Garmin retains the exclusive right to repair or replace the unit or software or offer a full refund of the
purchase price at its sole discretion. SUCH REMEDY SHALL BE YOUR SOLE AND EXCLUSIVE
REMEDY FOR ANY BREACH OF WARRANTY.

To obtain warranty service, contact your local Garmin authorized dealer, or call Garmin Product Support at
one of the numbers shown below for shipping instructions and an RMA tracking number. The unit should
be securely packed with the tracking number clearly written on the outside of the pack age. The unit should
then be sent, freight charges prepaid, to any Garmin warranty service station. A copy of the original sales
receipt is required as the proof of purchase for warranty repairs.

Garmin International, Inc.
1200 East 151

st

Street,
Olathe, Kansas 66062, U.S.A.
Tel. [phone] or 800/800.1020
Fax [phone]

Garmin (Europe) Ltd.
Unit 5, The Quadrangle, Abbey Park Industrial Estate,
Romsey, SO51 9DL, U.K.
Tel. [phone]
Fax [phone]

GPS 18 Technical Specifications (190-00307-00 ) Rev. D

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Overview
The GPS 18 series products include an embedded receiver and an antenna. Based on the proven technology

found in other Garmin 12-channel GPS receivers, the GPS 18 tracks up to 12 satellites at a time while
providing fast time-to-first-fix, precise navigation updates (five times per second for the GPS 18-5Hz, and
once per second for the GPS 18 USB, 18 PC, and 18 LVC), and low power consumption. This generation
of GPS sensors adds the capability of FAA Wide Area Augmentation System (WAAS) differential GPS.
The GPS 18’s far-reaching capability meets the sensitivity requirements of land navigation as well as the
dynamics requirements of high-performance aircraft.

The GPS 18 design uses the latest technology and high-level circuit integration to achieve superior
performance while minimizing space and power requirements. All critical components of the system
including the RF/IF receiver hardware and the digital baseband are designed and manufactured by Garmin
to ensure the quality and capability of the GPS. The hardware capability combined with software
intelligence makes the GPS 18 easy to integrate and use.

The GPS 18 series products are designed to withstand rugged operating conditions and are waterproof to
IEC 60529 IPX7, immersion in 1 meter of water for 30 minutes. These complete GPS receivers require
minimal additional components to be supplied by an OEM or system integrator. A minimum system must
provide the GPS with a source of power and a clear view of the GPS satellites. Internal FLASH memory
allows the GPS to retain critical data such as satellite orbital parameters, last-known position, date and
time. End user interfaces such as keyboards and displays are the responsibility of the application designer.

1.3 FEATURES

• 12-channel GPS receiver tracks and uses up to 12 satellites for fast, accurate positioning and low

power consumption.

• Differential DGPS capability using real-time WAAS corrections yielding position errors of less than 3

meters.

• Compact, rugged design ideal for applications with minimal space. Receiver position information can

be displayed directly on a chartplotter or PC.

• User initialization is not required. Once installed, unit automatically produces navigation data after

position fix is acquired.

• User-configurable navigation mode (2-dimensional or 3-dimensional fix).

• (GPS 18 LVC and GPS 18-5Hz only) Highly accurate measurement pulse output for precise timing

measurements: one-pulse-per-second (1 Hz) for the GPS 18 LVC or 5 Hz for GPS 18-5Hz. Pulse wi dth
is configurable in 20 millisecond increments from 20 ms to 980 ms with 1 µs accuracy.

• Configurable for binary format carrier phase data output.

• FLASH-based program and non-volatile memory. New software revisions available through Web site

download. Non-volatile memory does not require battery backup.

• Onboard rechargeable backup battery to maintain the real-time clock for up to 3 weeks.

• Configurable parameters include expected position, current time and date, preferred position fix type

(2D, 3D, or automatic), and velocity filter time constant (none, automatic, or your choice between 2
and 255 seconds).

• Waterproof design allows continuous exposure to the prevailing weather conditions at most locations.

GPS 18 Technical Specifications (190-00307-00 ) Rev. D

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1.4 GPS 18 SERIES

There are several different versions of GPS 18 available. Refer below for a list of the three major divisions
of the GPS 18 Series.

1.4.1 GPS 18 USB

The GPS 18 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. After the drivers are
loaded, the device appears to the Windows operating system as a
USB-connected device and appears in Device Manager as a Garmin
USB Device.

1.4.2 GPS 18 PC

The GPS 18 PC interfaces to a serial port of a computer via a DB-9
connector and receives power through a 12-volt cigarette lighter
adapter. The unit accepts TIA-232-F (RS-232) level inputs and
transmits voltage levels that swing from zero V (ground) to 5 V
TIA-232-F (RS-232) polarity.

The GPS 18 PC can cause an issue with Windows operating systems
if the DB9 connector is plugged into the computer before the
navigation software is up and running. The Windows operating
system may interpret the serial connector on the GPS 18 as a serial
mouse. Please refer to Appendix D: GPS 18 PC/ LVC/18-5Hz &

Windows Serial Mouse Issue for complete details.

1.4.3 GPS 18 LVC, GPS 18 LVC-5m, and GPS 18-5Hz

These products interface to a serial port. The units accept TIA-232-F (RS-232) level inputs and transmit
voltage levels that swing from ground to the positive supply voltage, TIA-232-F (RS-232) polarity. They
also have reverse polarity protection. The cable contains wires for power, ground, receive, transmit, and
measurement pulse output.

At the end of the cable, the wires are terminated in a connector that is
used by Garmin for testing purposes. Most customers will remove this
connector and replace it with another connector of their own choosing.
Removing the factory installed connector and/or replacing with another
customer-supplied connector will have no affect on the warranty (see
Section 1.2 Limited Warranty). The factory-installed connector will mate
with JST right-angle PCB-mount connector (m odel BM0 6B -SRSS -TB T )
or side-entry PCB-mount connector (model SM06B-SRSS-TB). You may
obtain technical information on these PCB-mount mating connectors
from the JST Web site: http://www.jst.com/.

Note: Unless otherwise specified, all references to the GPS 18 LVC also include the GPS 18 LVC-5m.

GPS 18 Technical Specifications (190-00307-00 ) Rev. D

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1.5 TECHNICAL SPECIFICATIONS

Specifications are subject to change without notice.

1.5.1 Physical Characteristics

1.5.1.1 Size

61 mm in diameter and 19.5 mm in height

1.5.1.2 Weight

• GPS 18 unit only (no cable): 1.9 oz (53.9 g)

• GPS 18 USB: 3.5 oz (100.4 g)

• GPS 18 PC: 6.5 oz (184.6 g)

• GPS 18 LVC (3 meter cable): 3.9 oz (110.6 g)

• GPS 18 LVC-5m (5 meter cable): 5.7 oz (161.6 g)

• GPS 18-5Hz (5 meter cable): 5.7 oz (161.6 g)

1.5.1.3 Color

Black

1.5.1.4 Case Material

Polycarbonate thermoplastic that is waterproof to IEC 60529 IPX7 level (immersion in 1 meter of water for
30 minutes)

1.5.1.5 Cable Length

• GPS 18 USB: 2 meter

• GPS 18 PC: 2 meter

• GPS 18 LVC: 3 meter (Garmin Part Number 010-00321-05)

• GPS 18 LVC-5m: 5 meter (Garmin Part Number 010-00321-06)

• GPS 18-5Hz: 5 meter

1.5.2 Electrical Characteristics

1.5.2.1 Input Voltage

• GPS 18 USB: 4.4–5.5 V

• GPS 18 PC: 8–30 V (Automotive supply from cigarette lighter jack)

• GPS 18 LVC: 4.0–5.5 V

• GPS 18-5Hz: 4.0–5.5 V

1.5.2.2 Input Current

• GPS 18 USB: 55 mA @ 5.0 V

• GPS 18 PC: 50 mA @ 13.8 V

• GPS 18 LVC: 60 mA @ 5.0 V

• GPS 18-5Hz: 65 mA @ 5.0 V

1.5.2.3 CMOS Serial Output Levels

• GPS 18 PC: 0 V to 5 V (Asynchronous Serial, TIA-232-F (RS-232) Compatible Polarity)

• GPS 18 LVC and GPS 18-5Hz: 0 V to Vin, between 4 and 5.5 V (Asynchronous Serial, TIA-232-F

(RS-232) Compatible Polarity)

GPS 18 Technical Specifications (190-00307-00 ) Rev. D

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1.5.2.4

-165 dBW minimum

GPS Receiver Sensitivity

1.5.3 Environmental Characteristics

• Operating Temperature: -30°C to +80°C

• Storage Temperature: -40°C to +90°C

1.5.4 GPS Performance

1.5.4.1 Receiver

WAAS enabled; 12 parallel channel GPS receiver continuously tracks and uses up to 12 satellites (up to 11
with Measurement Pulse Output active) to compute and update your position.

1.5.4.2 Acquisition Times

• Reacquisition: Less than 2 seconds

• Warm: Approx. 15 seconds (all data known)

• Cold: Approx. 45 seconds (initial position, time, and almanac known; ephemeris unknown)

• AutoLocateTM: 5 minutes (almanac known; initial position and time unknown)

• SkySearch: 5 minutes (no data known)

1.5.4.3 Update Rate

• GPS 18 USB, PC, and LVC: 1 record per second

• GPS 18-5Hz: 5 records per second

1.5.4.4 Accuracy

• GPS Standard Positioning Service (SPS )

Position: < 15 meters, 95% typical
Velocity: 0.1 knot RMS steady state

• WAAS

Position: < 3 meters, 95% typical
Velocity: 0.1 knot RMS steady state

• Measurement Pulse Output Time: ±1 microsecond at rising edge of the pulse

• Dynamics: 999 knots velocity (only limited at altitude greater than 60,000 feet), 6g dynamics

GPS 18 Technical Specifications (190-00307-00 ) Rev. D

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