I/O module(s) has (have) identified internal bus command as incorrect (Fault code 3, argument 0)

What does I/O-LED 3-0 mean?

One or more I/O modules connected to the Fieldbus Coupler have reported receiving incorrect internal bus commands. This indicates a critical communication issue on the internal bus, potentially due to a faulty module, corrupted signals, or a defective coupler, leading to unreliable data exchange.

• Interruption or severe corruption on the internal communication bus
• Defective I/O module generating or interpreting incorrect internal bus commands
• Defective coupler sending incorrect commands or experiencing internal bus issues

Click steps to track your progress.

1. 1

   Disconnect the Profibus cable from the coupler to isolate internal bus communication.

2. 2

   Plug the end module into the middle of the node to segment the internal bus and identify the faulty section.

3. 3

   Cycle the coupler's supply voltage (off and on again).

4. 4

   If the I/O LED continues to flash, shift the end module again to further isolate the defective segment.

5. 5

   If only one module is connected to the coupler and the I/O Err LED illuminates, replace the single I/O module or the coupler, as one of them is defective.