If any of the responses return Not-Acquired or Not-Registered (and the APN is correct), the wireless
network operator should be contacted for further troubleshooting.
Please note that it may take several seconds (or longer) for the 4520™ to communicate with the
modem and acquire the wireless network.
5.4.2 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$APP GPS?
The response should be similar to:
Lat=3304713, Lon=-11727730, Alt=0
Hdg=113 Spd=0 3D-RTIME HDOP=130 nSats=7
Installers are looking for the 3D-RTIME setting along with a valid Lat, Long pair (i.e. something other
than 0). If the GPS receiver does not have a valid lock within 2-3 minutes, installers should check
antenna placement (see the Installation Notes section for placement suggestions), the antenna
connector and that the antenna has a clear view of the sky. For further troubleshooting, installers
should contact CalAmp Support (
)
5.4.3 Inbound Verification
The last item to verify is that the 4530™ is sending data to the correct server. In general, this is a two-
step process that will need the aid of an observer on the back end. That is, a technician will have to be
logged in so they can monitor data coming into the backend mapping/vehicle management application.
First, verify that the 4530™ is using the correct Inbound IP address by using:
AT$APP INBOUND?
The response should be similar to:
INBOUND LMD
INBOUND 0 ADDR ddd.ddd.ddd.ddd:ppppp *
