What does my "FWD/REV" key on the front of the PowerFlex 525 not work?

The article describes a possible solution of why the "FWD/REV" key does not work on the PowerFlex 525 Drive.

If Parameter 46 (Start Source 1) is set to anything else but "Keypad", the FWD/REV key on the front of the drive will not work.

What does my "FWD/REV" key on the front of the PowerFlex 525 not work?