Cause : I/O COMM ERROR comes when communication error on control board, channel CH1. This means the drive is having difficulty receiving or transmitting data through this communication channel.

The code 7000 in your ABB ACS800 drive indicates a communication error on the control board (Channel CH1). This signifies an issue with the transmission and reception of data between the control board and other components within the drive or external devices connected through CH1.

1. Check connections of fiber optic cables on channel CH1.
2. Check all I/O modules (if present) connected to channel CH1.
3. Check for proper earthing of equipment. Check for highly emissive components nearby.