Defective Module; Physical Defect In Connectors; Wrong Connection Or A Loop Connection Or Missing Termination; Missing Or Defective Device - EKE-Electronics CVB1621A Technical Manual

4.5.2 Defective module

A transmission error can be caused by a defective module. All EKE
passed a production test procedure and are thus guaranteed to function properly.
However, a module may be damaged during shipment or handling.

4.5.3 Physical defect in connectors

A transmission error can be caused by a physical defect, such as oxidation, in the CVB
connectors or in the bus cable.
To find out whether the transmission error is caused by a physical error in connectors,
check the connectors visually.
4.5.4 Wrong connection or a loop connection or missing
termination
A transmission error may result from a wrong connection or a loop connection. The
terminators are by default ON the CVB module, but there is an option to terminate
externally. If termination is done outside the module, check that the terminators are not
missing or in the wrong places. Visually check all connections and terminations.

4.5.5 Missing or defective device

The slave devices in the CAN bus may be defective or the CVB configuration may not
match the slave devices in the bus. Check all connections, terminations and devices
and troubleshoot the devices according to their manuals.

4.5.6 Low signal level or missing signal

A transmission error can be caused by a low signal level. One possible cause for a low
signal level is that the other half of the differential signal is missing. Also, the entire
signal can be missing. You can measure the signal levels with an oscilloscope.
It is not recommended to use a multimeter, as it does not properly indicate
the status of the transmission line.
Do the following:
1 Set the vertical amplification of the oscilloscope to 1v/div and the time scale to 50µs/
div.
2 Connect oscilloscope channel 1 to pin 7 and channel 2 to pin 2 of connector X1 (or
X2).
3 Connect the ground of the oscilloscope channels to pin 3.
4 Set the oscilloscope for a differential measurement (channel 1 - channel 2) and
determine the cause of the problem by the resulting waveform.
CVB1621A and CVB2456A Technical Manual, ver. 3.00
Troubleshooting
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