Garmin 20x Specifications

GPS 20x

TECHNICAL

SPECIFICATIONS

Garmin International, Inc.

st

1200 E. 151

Olathe, KS 66062 USA

190-00880-00, Revision A

January 2008

a

Street

© 2008 Garmin Ltd. or its subsidiaries

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.
Liberty House, Hounsdown Business Park,
Southampton, Hampshire, SO40 9RB, U. K.
Tel. [phone] (outside the UK) 0808 2380000 (within the UK)
Fax [phone]

Garmin Corporation
No. 68, Jangshu 2

nd

Road, Shijr, Taipei County, Taiwan
Tel. [phone]
Fax [phone]

All rights reserved. Except as expressly provided herein, no part of this manual may be reproduced, copied,
transmitted, disseminated, downloaded, or stored in any storage medium, for any purpose without the express prior
written consent of Garmin. Garmin hereby grants permission to download a single copy of 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 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. Visit the Garmin Web site (

www.garmin.com) for current updates and supplemental information

concerning the use and operation of this and other Garmin products.
Garmin

®

, MapSource®, and WAAS Enabled® are registered trademarks of Garmin Ltd. or its subsidiaries and may

not be used without the express permission of Garmin.
Windows® is a registered trademark of the Microsoft Corporation.
Macintosh

®

is a registered trademark of Apple Inc.

Web site address: www.garmin.com

RECORD OF REVISIONS

Revision Revision

Description ECO #

Date

A 1/14/08 Initial Release --

190-00880-00 GPS 20x Technical Specifications Rev. A

Page i

TABLE OF CONTENTS

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

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

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

1.3 Overview.........................................................................................................................................................3

1.4 Features...........................................................................................................................................................3

1.5 Technical Specifications..................................................................................................................................4

1.5.1 Physical Characteristics.....................................................................................................................................4

1.5.1.1 Size.................................................................................................................................................... 4

1.5.1.2 Weight............................................................................................................................................... 4

1.5.1.3 Color.................................................................................................................................................. 4

1.5.1.4 Case Material..................................................................................................................................... 4

1.5.1.5 Cable Length..................................................................................................................................... 4

1.5.2 Electrical Characteristics................................................................................................................................... 4

1.5.2.1 Input Voltage..................................................................................................................................... 4

1.5.2.2 Input Current..................................................................................................................................... 4

1.5.2.3 GPS Receiver Sensitivity .................................................................................................................. 4

1.5.2.4 Environmental Characteristics........................................................................................................... 4

1.5.3 GPS Performance.............................................................................................................................................. 4

1.5.3.1 Receiver............................................................................................................................................. 4

1.5.3.2 Acquisition Times............................................................................................................................. 4

1.5.3.3 Update Rate....................................................................................................................................... 4

1.5.3.4 Accuracy ........................................................................................................................................... 5

1.5.4 Interfaces........................................................................................................................................................... 5

1.5.4.1 GPS 20x Electrical Characteristics.................................................................................................... 5

1.5.4.2 Garmin Interface and Garmin USB Protocol..................................................................................... 5

2 Mechanical Characteristics & Mounting...............................................................................6

3 GPS 20x Software Interface....................................................................................................7

3.1 Transmitted NMEA 0183 Sentences...............................................................................................................7

3.1.1 Sentence Transmission Rate.............................................................................................................................. 7

3.1.2 Transmitted Time .............................................................................................................................................. 8

3.1.3 Global Positioning System Fix Data (GGA)..................................................................................................... 8

3.1.4 GPS DOP and Active Satellites (GSA)............................................................................................................. 9

3.1.5 GPS Satellites in View (GSV)...........................................................................................................................9

3.1.6 Recommended Minimum Specific GPS/TRANSIT Data (RMC)..................................................................... 9

3.1.7 Sensor Status Information (PGRMT).............................................................................................................. 10

Appendix A: Earth Datum List..................................................................................................11

Appendix B: Garmin Binary Output Format...........................................................................14

LIST OF TABLES AND FIGURES

Figure 1. GPS 20x Top Case Dimensions.....................................................................................................................6

Figure 2. GPS 20x Side View........................................................................................................................................6

Figure 3. GPS 20x End View ........................................................................................................................................6

Table 1: NMEA 0183 Output Sentence Order and Size................................................................................................7

190-00880-00 GPS 20x Technical Specifications Rev. A

Page ii

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 20x 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 20x. 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
navigation.

FCC

Compliance

This product has been tested and found to comply with Part 15 of the FCC interference limits for Class B digital
devices FOR HOME OR OFFICE USE. These limits are designed to pr ovi de m ore reas onable protection against
harmful interference in a residential installation, and are more stringent than “outdoor” requirements.

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 may cause harmful interference to radio
communications if not installed and used in accordance with the instructions. 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 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 that is on a different circuit from the GPS unit.

• Consult the dealer or an experienced radio/TV technician for help.

This product does not contain any user-serviceable parts. Repairs should only be made by an authorized Garmin
service center. 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 regulatio ns.

190-00880-00 GPS 20x Technical Specifications Rev. A

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.

This product is intended to be used only as a travel aid and must not be used for any purpose requiring precise
measurement of direction, distance, location, or topography. Garmin makes no warranty as to the accuracy or
completeness of map data in this product.

THE WARRANTIES AND REMEDIES CONTAINED HEREIN ARE E XCLUSIVE AND IN LIEU OF ALL
OTHER WARRANTIES EXPRESS OR IMPLIED OR STATUTORY, INCLUDING ANY LIABILITY ARISING
UNDER ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PART I CULAR PURPOSE,
STATUTORY OR OTHERWISE. THIS WARRANTY GIVES YO U SPECIF IC LE GAL 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
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.

of the package. The unit should then be sent, freight

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.
Liberty House, Hounsdown Business Park,
Southampton, Hampshire, SO40 9RB, U. K.
Tel. [phone] (outside the UK) 0808 2380000 (within the UK)
Fax [phone]

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

190-00880-00 GPS 20x Technical Specifications Rev. A

Page 2

1.3 OVERVIEW

The GPS 20x includes an embedded receiver and an antenna. The GPS 20x tracks multiple satellites at a time while
providing fast time-to-first-fix navigation updates once per second. This generation of GPS sensors includes the
capability of FAA Wide Area Augmentation System (WAAS) differential GPS.

The GPS 20x design uses the latest technology and high-level circuit integration to ach ieve superior performance
while minimizing space and power requirements. The hardware capability combined with software intelligence
makes the GPS 20x easy to integrate and use.

The GPS 20x requires 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.

The GPS 20x 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. 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 FEATURES

• GPS receiver tracks and uses multiple satellites for fast, accurate positioning and velocity estimates.

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

meters.

• Compact design is ideal for applications with minimal space.

• Binary format data output over the USB interface transmits packets once per second. Refer to

Garmin Binary Output Format

.

Appendix B:

• Downloadable Spanner application allows the GPS 20x to output NMEA 0183 sentences. Refer to section

3.1 Transmitted NMEA 0183 Sentences.

• FLASH-based program allows new software revisions through a Web site download.

• Non-volatile memory does not require battery backup.

• Onboard rechargeable backup battery can maintain the real-time clock for up to 10 days.

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

(3D or automatic).

190-00880-00 GPS 20x Technical Specifications Rev. A

Page 3