Self-diagnosis Fault of Communication Option Card

What does CPF21 mean?

A self-diagnosis fault of the communication option card occurred, possibly due to noise or spikes on the communication line or a defective option board itself. This fault indicates a critical internal problem with the communication option card, leading to communication failure.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Replace the option board.

2. 4

   Replace the control board if the issue persists.