LMU-2x20™ Hardware and Installation Guide
V1.0.10
December 12, 2010
Copyright ©Calamp Wireless Networks Inc 2010
- 48 -
CalAmp Proprietary & Confidential
4.5.2
GPS Verification
The next step is to verify that the GPS receiver is seeing enough satellites to obtain a valid
GPS position. Again, installers have two choices on how to perform this verification. First,
like the Comm Verification, there is a GPS status LED (i.e., the one closest to the SMA
connector). If this LED is solid, then the LMU has found GPS service.
If the LED is not visible then GPS service may be verified using an AT Command:
AT$APP GPS?
The response should be similar to:
Lat=3304713, Lon=-11727730, Alt=0
Hdg=113 Spd=0 3D-RTIME HDOP=130 nSats=7
Installers are looking for the 3D-RTIME setting along with a valid Lat, Long pair (i.e.
something other than 0). If the GPS receiver does not have a valid lock within 2-3 minutes,
installers should check antenna placement (see the Installation Notes section for placement
suggestions), the antenna connector and that the antenna has a clear view of the sky. For
further troubleshooting, installers should contact CalAmp Support
