Abstract: The abnormal communication error of PLC bus system in Anhui Pingwei Power Plant was described. According to the detection and analysis of hardware and software, it is determined that the reason of the communication error is electromagnetic interference. The cause of the electromagnetic interference was analyzed; and the concrete solution was given, which provides reference for processing of similar problems.


Key words: RI/O (remote I/O) bus, PLC (programmable logic controller), communication error, EMI (electro-magnetic interference)