Research of Conversion Algorithm of Programmable Logic Controller Ladder Diagram to Assembly Language

Ladder diagram language is one of the most widely used languages in the IEC61131-3 standard. This paper presents a new strategy of converting soft PLC ladder diagram to the assembly language: records ladder diagram with binary tree, analyzes series and parallel structure of components, then realizes the conversion from the ladder diagram to assembler language. As empirical study proves, this strategy can express the relations of various ladder diagram components clearly. The conversion process is quick and accurate.