Description
在PLC控制系统的故障中，CPU占5%，I/O接口占15%，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。
Allen Bradley Guardmaster Safety Relay 440R-ZBR520AZ1
Allen Bradley Guardmaster Safety Relay 440R-ZBR520AZ1
Allen Bradley Guardmaster Safety Relay 440R-F2308 NEW
AB Allen Bradley Safety Relay 440R-E23031 Guardmaster
AB 440R-D23021 SER A SAFETY RELAY GUARDMASTER MINOTAUR
