Modelling and compilation method for multi-PLC control program

摘要

For the large-scale multi-PLC control system, a network-oriented programming method is proposed. Regarding the control network as a large-scale virtual PLC device, the engineers can program the whole system using all of the resources in the control network directly. A modelling and compilation method for control program is also put forwarded and an event graph model for the programs is created. The serial control program can be decomposed into parallel tasks by event graph model analyse and traversal rule. According to the topology of control network, the event graphs are grouped, and the instructions can be downloaded to the corresponding PLC automatically. The variables of devices can be synchronised through network communication. The experimental result shows that this method can improve the program efficiency of the networked PLC control system, and keep the running logic according with the original program.