CMM4 does not pass proper GPS sync to connected modules

If the Event Log tabs in all connected modules contain Loss of GPS Sync Pulse messages, perform the following steps.

Troubleshooting CMM4 not passing sync


Verify that the GPS antenna has an unobstructed view of the entire horizon.


Verify that the GPS coaxial cable meets specifications.


Verify that the GPS sync cable meets specifications for wiring and length.


If the web pages of connected modules indicate any of the following, then find and eliminate the source of noise that is being coupled into the GPS sync cable:

·         In the GPS Status page:

o    anomalous number of Satellites Tracked (greater than 12, for example)

o    incorrect reported Latitude and/or Longitude of the antenna

·         In the Event Log page:

o    garbled GPS messages

o    large number of Acquired GPS Sync Pulse messages

GPS signal acquisition must not take longer than 5 minutes from unit startup.


If these efforts fail to resolve the problem, then request an RMA for the CMM4.