摘要
逻辑设计法就是应用逻辑代数以逻辑组合的方法和形式设计电气控制系统。PLC梯形图程序的基本形式也是逻辑运算与、或、非的逻辑组合,逻辑函数表达式与梯形图有对应关系,可以相互转化。本文通过四个具体案例,分析控制任务要求,列出真值表或写出逻辑函数表达式,从而写出控制任务的PLC梯形图程序。
Logic design is to use logical algebra to design electric control system by logical combination. The basic form of the PLC ladder diagram program is also the logical combination of logical calculation "and", " or", and "without". The expression of logical function and the ladder diagram correspond with each other and can be transformed into each other.
