Err Node Guard "Life guarding event"

What does 260 mean?

The controller, configured as a CAN slave, did not receive a 'Node Guarding' telegram from the CAN master within the configured 'Node Life Time'. This indicates a loss of communication supervision on the CAN bus.

• CAN master controller (e.g., PLC) has failed to send 'Node Guarding' telegrams to the drive (CAN slave) within the configured 'Node Life Time' (e.g., Parameter C0805).
• Broken or loose connection in the CAN bus cabling (e.g., X3 connector), preventing communication with the master.
• Incorrect CAN bus termination resistors (e.g., 120 Ohm at each end of the bus) causing signal reflections and data loss.
• CAN master controller fault, causing it to stop transmitting guarding messages or to reset its CAN interface.
• Excessive CAN bus traffic or electromagnetic interference (EMI) causing message collisions and missed guarding frames.
• 'Node Life Time' (C0805) or 'Node Guarding Time' (C0804) parameters are set too aggressively for the network conditions or master's response time.

Click steps to track your progress.

1. 1

   1. Verify the CAN master controller (e.g., PLC) is operational and actively sending Node Guarding messages according to its program.

2. 2

   2. Inspect the CAN bus cable (e.g., between X3 connectors on devices) for physical damage, loose connections, or incorrect pinout.

3. 3

   3. Use an oscilloscope to verify CAN bus differential signals (CAN_H, CAN_L) and confirm proper voltage levels and data integrity.

4. 4

   4. Check the CAN bus termination resistors; ensure one 120 Ohm resistor is present at each physical end of the bus and none in between.

5. 5

   5. Increase the 'Node Life Time' (Parameter C0805) or 'Node Guarding Time' (C0804) in small increments (e.g., 20%) to account for network latency.

6. 6

   6. Check CAN bus diagnostics on the drive (e.g., P5-12 for CAN bus status) and on the master controller for communication errors.