摘要
程序依赖关系分析在对程序进行测试、维护、分析和优化过程中起着重要作用。梯形图（LD）程序中数据定义和数据引用会导致梯级之间存在数据依赖关系和潜在并行性。针对该问题，通过构造数据依赖关系有向图构建数据依赖关系，提取LD图梯级间的数据流和数据依赖信息，并从数据依赖关系有向图中获得LD图并行梯级。实验结果表明，通过并行提取可使LD图的扫描周期缩短至原来的20％～50％。
Program dependence relation analysis is an important method of testing, maintaining, analyzing and optimizing program, especially parallel extraction. The dependence of rungs caused by definition and reference has the same variable and the parallelism of sequential rungs in Ladder Diagram（LD）. Aiming at the problem, a method is proposed to extract LD diagram rung data flow and data dependence relation by constructing data dependence relation directed diagram, recognize LD diagram parallel rung in data dependence relation directed diagram. Experimental result shows that the LD diagram scan time is shorten to 50%-20% by concurrent extraction.
出处
《计算机工程》
CAS
CSCD
2014年第2期67-70,76,共5页
Computer Engineering
基金
浙江省自然科学基金资助项目"动态可重构的嵌入式构件描述及重构方法的研究"(Y1090448)
关键词
可编程控制器
梯形图
数据依赖
有向图
并行性
并行梯级
Programmable Logic Controller（PLC）
Ladder Diagram（LD）
data dependence
directed diagram
parallelism
parallel rung
