Research And Application Of PLC System Based On IEC61131-3 Standard

IEC61131-3 is the first standard programming language of automation control system. Its openness and superiority attract many research interests and it becomes a widely used international standard. With Ethernet's development in Fieldbus Control System, It is a significant work to research on PLC control system.Based on the IEC61131-3 software program specification, a PLC system scheme accord with the characteristic of industrial control system and Fieldbus technique is designed. The system main controller can extend slave device which support standard Modbus protocol with RS-485 Bus and support universal configuration software.The embedded software development in the Ethernet controller is based on Dynamic C development environment and RCM2250 core module. The whole program, including function block design, system register design, extended device management, communication process, and so on, is finished in the system.A application sample of PLC system in steel rolling direct drive of Golden Bull of application in industrial field is given. System state and alarm process function is implemented and the whole system is running steadily and operated conveniently. By the research and application in the field, the main controller is verified in the theory and field application. It has many advantages in system opening, human resource saving and software reusing.