Application of OPC to Realize the Communications between WinCC and Master-Slave PLC in the PROFIBUS Network

Network is the direction of development for industrial control, application of PROFIBUS-DP network consisting of S7-300 PLC S7-200 PLC produced by Siemens is becoming more and more widely. WinCC is powerful PC monitoring configuration software, often need to read and write datum of master-slave PLC in the network. This paper discusses the method of direct communication between WinCC and master-slave PLC in the PROFIBUS network under the premise of not affecting communication between PLC in the network.