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。
QMC 2284-MBE3409 SERVO DRIVE
METCAL SMTC-145 QUAD TIP SOLDERING CARTRIDGE (NEW)
METCAL SMTC-119 QUAD TIP SOLDERING CARTRIDGE (NEW)
METCAL SMTC-143 QUAD TIP SOLDERING CARTRIDGE (NEW)
ALLEN-BRADLEY 802T-BAPV OILTIGHT LIMIT SWITCH
METCAL SMTC-186 QUAD TIP SOLDERING CARTRIDGE (NEW)
METCAL SMTC-043 QUAD TIP SOLDERING CARTRIDGE (NEW)
H10S CLT-100 Power Supply For Adj. Power Screwdriver
HP 3488A Switch Control Unit ONLY W/(HP-IB)
NI FP-DO-401 16-CHANNEL Discrete Output Module W/BASE
SIEMENS 6ES7 153-2AA02-0XB0 SIMATIC S7 6ES71532AA020XB0
