CAN Module Warning/Bus-Off

What does ce6 mean?

The CAN function module on the FIF has reported a 'Warning' or 'Bus-Off' status, indicating underlying communication issues. This often points to problems with bus termination, cable shielding, PE connection, or an overloaded bus. While 'Warning' might allow limited operation, 'Bus-Off' will completely halt communication.

• Incorrect or missing CAN bus termination resistors (120 Ohm) at the network ends, causing signal reflections.
• Insufficient or damaged shielding on the CAN bus cable, leading to electromagnetic interference (EMI).
• Poor or intermittent Protective Earth (PE) connection for the CAN module or the drive controller.
• Ground loops caused by multiple grounding points for the CAN network, inducing noise.
• Excessive length of the CAN bus cable exceeding recommended limits for the baud rate (e.g., 100m at 500kbit/s).

Click steps to track your progress.

1. 1

   Verify the presence and correct placement of 120 Ohm termination resistors at both physical ends of the CAN bus.

2. 2

   Inspect the CAN bus cable shielding for damage and ensure it is properly connected to ground potential at one end.

3. 3

   Check the Protective Earth (PE) connection for the CAN module and the drive controller, ensuring low impedance.

4. 4

   Use a multimeter to confirm that there are no unintended ground loops or multiple grounding points for the CAN bus.

5. 5

   Measure the total length of the CAN bus cable and compare it against the maximum recommended length for the configured baud rate (P8-01 or P8-11).