Compiling Ladder Diagram Based on Node Method

Ladder diagram is widely used in PLC Program. The Compiling part of the ladder diagram of soft PLC is very important. According to the analysis of the compiling part of the PLC ladder diagram, this paper presents node method to compile it in the VC++ environment. The node method eliminates the traditional compilation process into the Instruction List. At last, the correctness of the node method is test and validated by examples.