CAN Bus momentary data freezes - Causes?

I have an Italian assembly machine that uses CAN bus for I/O which then goes thru an ESD CAN to DP bridge to the S7-315 2DP.  I am bringing this machine back to life after 2 years in storage but the CPU battery had failed. 

I have had great assistance from folks at ESD and the machine is running now but we continue to have random momentarily CAN bus data freezes. I am able to capture the CAN data in a trace file and don't see any reports of frame errors or other errors. I do see RTR requests at address 070A which never get a reply.  Could this be a problem?

If I have electrical noise on the CAN bus how would that show up in the trace data?

Any help would be appreciated.

Doug