Description
输入设备占45%，输出设备占30%，线路占5%。前二项共20%故障属于PLC的内部故障，它可通过PLC本身的软、硬件实现检测、处理；而其余80%的故障属于PLC的外部故障。因此，PLC生产厂家都致力于研制、发展用于检测外部故障的专用智能模块，
Allen Bradley Guardmaster Safety Relay 440N-S32013
AB 440R-E23030 SER A SAFETY RELAY GUARDMASTER MINOTAUR
Guardmaster MSR6R/T Universal Safety Relay 440R-C23018
Allen-Bradley Guardmaster Safety Relay MSR142RTP
Allen Bradley / Guardmaster Safety Relay, #440R-E23030
