PLC梯形图向语句表的转换算法及实现

基于块生长观念提出了一种全新的将梯形图转化为语句表的转换算法。该转换算法以梯级为单位,采取＂自左而右,自上而下＂的扫描顺序,通过竖线标志来确定元件间的串并联关系,借助存放块（依据元件间的串并联关系不断生长的块）的栈来定位下次扫描的元件对象。该算法不仅能清晰地表达出梯形图各元件的逻辑关系,语句表转换过程准确快速,还能成功的实现梯级中包含多分支输出的复杂梯形图到语句表的转换。

Algorithm and realization transformation from PLC ladder diagram to instruction list

A new transformation algorithm which transformers the ladder diagram to PLC instruction list based on block-growth is prompted.This algorithm uses ladder step as the unit,scans the serial/parallel relationship among the components according to the sequence of "left-right" and "top-down",and locates the next component using stack.The data elements block in the stack grows according to the serial relationship between the components during the traverse.This algorithm can clearly express the logic relationship between the components in the ladder diagram,accurately and quickly translate the diagram into the instructions,and accomplish to translate the complex ladder diagram which includes multi-branch into the instruction list.