由于该系列PLC 解算梯形图流程的特殊性，容易引起控制电路中电气联锁环节的失效。本文详细分析了故障产生的原因，并提出两种解决方案。关键词： 电气联锁，梯形图Abstract： Owing to the peculiarities of the PLC Ladder Logic graphic, there may well be thepossibilities of the invalidation in the electric chain lock on the circuit . This paper in particulartrys to analyze the cause of the creation of the breakdown and at the same time provide us with two solutions.Keywords: Electric chain lock, Ladder