基于多叉树的梯形图向指令表转换算法

Transformation Algorithm from Ladder Diagram to Instruction List Based on Multi-tree

摘要:

针对目前可编程逻辑控制器(PLC)编辑软件中梯形图向指令表转化算法的缺陷,通过对梯形图语言的分析与研究,并考虑到梯形图和指令表在实际应用时的优劣点,提出了一种借助多叉树来实现PLC梯形图向指令表转换的算法;该算法采取从左至右,从上至下的扫描原则将梯形图构建成多叉树,借助多叉树来反应图符间的逻辑关系,然后通过后序遍历多叉树来得到指令表程序;此算法在处理多重串并联结构梯形图时具有更高的效率,同时适用于堆栈指令,使得该算法具有更好的通用性。

Abstract:

Aiming at the shortcomings of the transformation algorithm from ladder diagram to instruction list in the current programmable logic controller(PLC) editing software, this paper presents an algorithm to realize the transformation from PLC ladder diagram to instruction list based on multi-tree. Through the analysis and research of ladder diagram, shows the advantages and disadvantages of the ladder diagram and instruction list in practical application. The multi-tree data structure is created following the scanning principle that from left to right, from top to bottom. And the multi-tree is used to reflect the logical relationship between the diagrams. Then get the instruction list by post-traversing the multi-tree.This algorithm has higher efficiency when dealing with the ladder diagram which has multiple series-parallel structures. And it is also suitable for the stack instruction, which makes the algorithm more versatile.