Communication Errors; Missing Configuration - EKE-Electronics CVB1621A Technical Manual

Troubleshooting
When you see the dbg> prompt on the screen, the software is successfully started and
you can start entering commands. If any of the self-tests fails, the diagnostic
commands are not available.
If the status of any of the self-tests is FAILED, the system resets the software and runs
the self-tests again. If the status still remains FAILED, there is a physical error in the
module. In such a case, you cannot test that specific module with the diagnostic
commands.
When the software has started:
1 Check the module information and firmware versions of the CVB and master
module (CPG/CPS).The software version of the CVB module can be checked by
executing the command ver (refer to chapter 5.6.4 on page 44). How to check the
correct firmware version of the master module refer to the corresponding module's
Technical Manual.
2 Compare this information with the change notices to make sure that the firmware
versions are correct.

4.5 Communication errors

If the CAN Bus does not function normally, the problem can be either in the CVB
module or in the bus itself. If the problem is with the bus, you can only troubleshoot it
on board the train. If the problem is with the module, remove the module from the rack,
replace it with a spare one, and send the defective module to maintenance.
The following sections give you hints on analysing error situations and finding out
whether there is a problem with the bus.
You need to rule out the following causes for the error situation:

Missing configuration

Defective module
Wrong connection or a loop connection or missing termination
Missing or defective device
Physical defect in connectors
Low signal level or missing signal
Defective termination
4.5.1 Missing configuration
This situation is most likely to occur if the system has been reset for some reason, and
the CVB has not re-received its configuration from the Gateway CPU. In this case, the
green ST LED is ON, but there is no data transmitting, i.e. the green UB LED is not
blinking at all.
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CVB1621A and CVB2456A Technical Manual, ver. 3.00