Cause: CANopen Communication Interrupt comes when communication interruption on the CANopen fieldbus. This can be due to hardware issues, wiring problems, network configuration errors, or software settings.

"COF" fault in Schneider ATV950 drive indicate "CANopen Communication Interrupt". This means a disruption in the communication over the CANopen network.

Here are steps to troubleshoot and resolve this fault:

1. Check Physical Connections:

• Cables and Connectors: Inspect all CANopen cables and connectors for any loose connections, damage, or improper seating.
• Terminations: Ensure the CANopen network is properly terminated with 120-ohm resistors at both ends of the bus.

2. Inspect Network Configuration:

• Node Addressing: Verify that each device on the CANopen network, including the drive, has a unique node address to avoid conflicts.
• Baud Rate: Ensure that the baud rate settings are consistent across all devices on the network.

3. Verify Drive Settings:

• Communication Parameters: Check the CANopen communication parameters in the drive's settings. This includes node address, baud rate, and other protocol-specific settings.
• Firmware Updates: Make sure the drive’s firmware is up-to-date to include any fixes or improvements related to CANopen communication.

4. Monitor Network Traffic:

• Network Analyzer: Use a CANopen network analyzer or diagnostic tool to monitor network traffic and identify any errors or communication interruptions.
• Error Logs: Check the drive’s error logs and the network master’s logs for communication error messages or diagnostic codes.

5. Inspect Network Topology:

• Topology: Ensure the network topology adheres to CANopen specifications. Avoid long stubs or improperly branched networks that can cause reflections and communication errors.
• Cable Length: Verify that the total length of the CANopen cable does not exceed the maximum allowed by the baud rate being used.

6. Electromagnetic Interference (EMI):

• Shielded Cables: Use shielded CANopen cables to minimize electromagnetic interference. Ensure the shielding is properly grounded.
• Cable Routing: Avoid routing CANopen cables parallel to high-power cables to reduce noise induction.