Research and Implementation of PLC Communication Network Based onCAN

Field bus is an industrial data bus which has developed rapidly in recent years. It is mainly used to solve digital communications among field equipments and message passing between field equipments and executive control systems. CAN bus is a kind of serial communication network supporting distributed control and real-time control effectively, and it applies double serial communication mode and has good error-detecting capacity, which makes it can work in high-noise or jammed environments and has higher reliability. The paper proposes PLC communication network scheme based on CAN bus. The scheme configures a RS232-CAN gateway on upper computer PC and each PLC to make upper computer PC and PLC have the ability of CAN bus communication for creating PLC communication network based on CAN bus. PLC network created by the scheme not only can realize centralized monitoring of PC on several PLCs and direct com- munication among PLCs, but also has higher cost and higher ability of system extension.