Algorithm and Realization of Transformation from PLC Ladder Diagram to Instruction Table
Zhe Zhou · Control Engineering of China · 2006
Aiming at the limitation and lack of the current editing software for PLC ladder diagram,based on the idea of oriented-object,an optimal algorithm to convert ladder diagram to instruction table is presented.A concrete solution of grammar checking,constructing logic tree and traversal of the tree to come up with instruction table are introduced.With flexible mechanism of class management,the algorithm is successfully applied to the editing software to realize the transformation from graph language to text language.As procedure is fairly close to the binary code,PLC ladder diagram is transformed to the instruction table,then the logic of procedure is educed through the explanation to the instruction table of interpreter,so that the procedure can be run on PC.The software based on this algorithm is powerful and simple to operate,and convenient to use.