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。
Moog M040-104 Portable Servo Valve Tester New
Indramat Servo Motor Mdl MDD090C-N-030-N2M-110GB1 Used
Parker D1FVE50BCVLB35 / D31FHE01C4NS00XG010 Valve Ass’y
Moog D662Z1910E Proportional Valve D061-857B Rebuilt
Moog 78-131C Servo Valve Used, Tested w/6 Mo Warranty
Moog Servo Valve 760A185A Rebuilt 13 Mo Warranty
Bosch 0811 404 605 / 0811 404 661 Valve 0811404661 New
Rexroth 4WS2EM10-45/20B2ET315K8AM Servo Valve Rebuilt
Rexroth 4WRGE10V25L-12/315G24K31/C1M Valve New NOS
Moog Husky Proportion Valve D682Z4809/D633-7368 Rebuilt
Moog Husky Proportion Valve D682Z4709B/D633-7115 Rebilt
