Cause : Communication error comes when there is no control data was received from the connected PLC when using serial communications.

"CE fault" indicate there in no communication between master & slave due to incorrect parameter or faulty wiring.

1. The baud rate setting is incorrect.
2. Fault occurs to the communication wiring.
3. The communication address is wrong.
4. There is strong interference to the communication. 
5. Set proper baud rate.
6. Check the communication connection distribution.
7. Set proper communication address. 
8. Chang or replace the connection distribution or improve the anti-interference capability.