PLC控制系统的故障诊断技术

Fault Diagnosis Technology of PLC Control System

PLC控制系统故障诊断包括外设、系统和硬软件诊断。其块堆栈、中断堆栈和局部堆栈通过系统自诊断可自动生成各部分状态,经编程器读写状态字和控制字能判断系统故障原因和部位。调用编程器的状态测试、输入/输出信号、与内存比较可实现PLC自诊断。输入开关、输出指示灯用直接检测法检测。在系统初始化程序中插入键短路检测程序可判断键的故障。首发故障使用程序中定义首发故障标志而诊断。

Fault diagnosis of PLC control system includes fault diagnosis of peripheral equipment, hardware and software of system. The block storehouse, interrupt storehouse and local storehouse can automatically create the state of each part by self-diagnosis of system. Fault causation and fault position of the system can be judged with programmer reading or writing state word and control word. By calling the state test, input or output signal, comparing memory, it can complete PLC self-diagnosis. Input switch, output pilot lamp is tested with direct test way, and the keyboard fault can be judged by inserting keyboard short circuit program in initialization program of system. The first fault can be tested through defining the symbol of first fault in the program.