What causes a ATV58 to receive an error code Err9
Error code #9 is an internal error in the keypad display software.
If the keypad display is remotely mounted, electrical noise may be present.
Cycle power on the drive controller to see if resets.
If there is another drive on the site exchange the keypads to see if the problem stays with the keypad or drive. If the problem stays with the drive replace the control board. Replace keypad if problem goes away.
It may be best to send the entire drive into the repair depot for service. Contact any SquareD distributor for assistance.