CANopen Communication Fault

What does COF mean?

This fault indicates a detected communication problem on the CANopen network. It means the drive is unable to send or receive data from other devices on the bus, leading to loss of control or monitoring via CANopen.

• CANopen network cable damage (e.g., open circuit in CAN_H or CAN_L, short to shield).
• Incorrect CANopen baud rate (e.g., Parameter P7-02) or node ID (e.g., Parameter P7-01) settings on the drive.
• Missing or incorrectly placed 120 Ohm termination resistors at the physical ends of the CANopen bus.
• Excessive electrical noise or ground loops on the CANopen network interfering with signal integrity.
• Faulty CANopen master device or another node on the network causing bus errors.

Click steps to track your progress.

1. 1

   1. Inspect the CANopen network cable for physical damage, ensuring proper shielding and twisted pair integrity.

2. 2

   2. Verify Parameter P7-01 (CANopen Node ID) is unique on the network and P7-02 (CANopen Baud Rate) matches all other devices.

3. 3

   3. Confirm that 120 Ohm termination resistors are correctly installed ONLY at the physical ends of the CANopen bus.

4. 4

   4. Check CANopen bus voltage levels (e.g., between CAN_H and CAN_L) using an oscilloscope for proper signal integrity.

5. 5

   5. Disconnect other CANopen devices one by one to isolate a potentially faulty node or master device on the bus.