描述
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。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，进一步提高系统的可靠性。
CM 800 Lifting Magnet O.S. Walker 1760 lb capacity
Signode banding strapping combination tool AH-114 1 1/4
Signode banding strapping combination tool AH-114 1 1/4
Heavy Lifting Magnet 1760 lb capacity
Nu-Era 10 Drawer Storage Cabinet Tool Box
Sperry Vickers Deceleration Valve Check DT15S2-060-K-11
Signode banding strapping combination tool AH-114 1 1/4
Hydraulic Cylinder approx 14 1/4″Bore 3 1/2′ Stroke
