Cause : CANopen bus off error comes when the master receives wrong communication package, the CbFE fault occurs or too much interference on BUS. The master receives wrong package when the CAN_H and CAN_L communication cables are short, CbFE fault occurs.

1. Make sure the CANopen card is installed.
2. Reset CANopen speed.
3. Verify the wiring and grounding of the communication circuit.
4. Make sure the communication circuit is wired in series.
5. Use CANopen cable or add terminating resistance.
6. Check or replace the communication cable.