Trimble Outdoors AgGPS 252 Interference

5 Troubleshooting

42 AgGPS 252 Receiver User Guide

Interference

Problem Possible solution

Strong magnetic fields

Strong magnetic fields have no

effect on GPS or satellite DGPS

signals.

However, some computers and other

electric equipment radiate

electromagnetic energy that can

interfere with a GPS receiver.

If you suspect interference from a local magnetic

field, move the receiver away from, or turn off, the

suspect electronics while observing the number of

satellites being tracked on the receiver or the signal-

to-noise ratio (SNR) of the satellite. If the SNR goes

up when the electronics are turned off, there may be

interference from the local electronics.

FM 2-way radios

Transmitting FM 2-way radios can

interfere with OmniSTAR, WAAS,

and GPS signal reception.

Make sure that there is at least 1m (3 ft) between

the FM 2-way radio antenna and the receiver.

Engine noise

An unshielded ignition system can

cause enough noise to block

reception of a differential signal.

Use resistor spark plug wires on the vehicle ignition

system.

An alternator can cause noise that

interferes with a differential signal.

Use bypass capacitors, commonly available in

automotive stores for cleaning up interference to CB

and other radios. If the problem persists, shield

engine components with aluminum foil.

Relocate the antenna on the machine.

Determine the optimal antenna location by

watching the SNR value on the AgRemote Home

screen.

Note – Before replacing engine parts in an attempt

to solve this problem, make sure that the problem is

not caused by a computer or power source near the

receiver. Some computers and their power sources

cause noise that disrupts GPS and satellite DGPS

signals.

Ag252_100B_UserGuide_ENG.book Page 42 Thursday, July 28, 2005 4:06 PM

Contents

Main trimble_support@trimble.com www.trimble.com C Recycling in Europe Page Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . .1 2 Overview . . . . . . . . . . . . . . . . . . . . . . . . .3 3 Installing the Receiver. . . . . . . . . . . . . . . . . 17 Page Introduction C Overview Page Page Page Page 2 Overview 8 AgGPS 252 Receiver User Guide Note WAAS/EGNOS and OmniSTAR VBS use the Satellite Differential GPS positioning method. Table 2.1 LED sequences with Satellite Differential GPS or Autonomous positioning Table 2.2 LED sequences with RTK positioning AgGPS 252 Receiver User Guide 9 Overview 2 Table 2.3 LED sequences with OmniSTAR HP positioning Table 2.2 LED sequences with RTK positioning (continued) Page Page Page AgGPS 252 Receiver User Guide 13 Overview 2 Table 2.5 Factors that influence the accuracy of GPS positions 2 Overview 14 AgGPS 252 Receiver User Guide Table 2.5 Factors that influence the accuracy of GPS positions (continued) Page Page Installing the Receiver Page C Page Page Page Page Page AgGPS 252 Receiver User Guide 25 Installing the Receiver 3 Table 3.4 Port B pinout Table 3.3 Port A pinout (continued) Page Configuring the Receiver D/3D 07 DOP03 WAAS 122 04 Page Page Operate in RTK Mode Page AgGPS 252 Receiver User Guide 33 Configuring the Receiver 4 The default port settings are: Table 4.1 Port input settings I RTCM 9600 8N1 0 NMEA 4800 Page Page Troubleshooting 38 AgGPS 252 Receiver User Guide Global Positioning System (GPS) AgGPS 252 Receiver User Guide 39 Troubleshooting 5 40 AgGPS 252 Receiver User Guide Page 42 AgGPS 252 Receiver User Guide Interference AgGPS 252 Receiver User Guide 43 Troubleshooting 5 GPS receiver AgRemote utility FlashLoader 200 upgrade utility Page Page AgGPS 252 Receiver User Guide 47 Ag252_100B_UserGuide_ENG.book Page 47 Thursday, July 28, 2005 4:06 PM START HERE Figure 6.1 Troubleshooting system hardware and power 48 AgGPS 252 Receiver User Guide Ag252_100B_UserGuide_ENG.book Page 48 Thursday, July 28, 2005 4:06 PM R E H AgGPS 252 Receiver User Guide 49 Ag252_100B_UserGuide_ENG.book Page 49 Thursday, July 28, 2005 4:06 PM R E H 50 AgGPS 252 Receiver User Guide Ag252_100B_UserGuide_ENG.book Page 50 Thursday, July 28, 2005 4:06 PM R E H AgGPS 252 Receiver User Guide 51 Ag252_100B_UserGuide_ENG.book Page 51 Thursday, July 28, 2005 4:06 PM START HERE Figure 6.5 Using AgRemote to troubleshoot RTK Page APPENDIX A AgGPS 252 Receiver User Guide 53 Specifications Tabl e A. 1 AgGPS 252 receiver A Specifications TableA.2 lists the performance characteristics of GPS channels. 54 AgGPS 252 Receiver User Guide Table A.2 GPS channels performance Tabl e A. 1 AgGPS 252 receiver (continued) AgGPS 252 Receiver User Guide 55 Receiver Table A.3 L-Band satellite differential correction receiver with OmniSTAR support Table A.2 GPS channels performance (continued) TableA.4 lists the receiver default settings. APPENDIX B AgGPS 252 Receiver User Guide 57 Third-Party Interface Requirements Table B.1 Third-party software interface requirements B Third-Party Interface Requirements TableB.2 lists the interface requirements for connecting an AgGPS receiver to third-party hardware. Table B.2 Third-party h ardware interface require ments Table B.1 Third-party software interface requirements (continued) AgGPS 252 Receiver User Guide 59 Third-Party Interface Requirements B Table B.2 Third-party hardware interface requirements (continued) B Third-Party Interface Requirements 60 AgGPS 252 Receiver User Guide Table B.2 Third-party hardware interface requirements (continued) Index Numerics A B C D E F G H I J L M P R S T U V W Y