| 摘要 |
PURPOSE:To realize the definite understanding and its corresponding treatment for the conditions of a fault, by executing an instruction of a fault detecting program which is set optionally to a user program memory as a part of a user program. CONSTITUTION:A programmable controller is provided with a user program memory 1 which stores a user program, an input circuit 2 to which an external input signal is applied, an output circuit 3 which delivers an output signal, an input/output memory 4 which functions as a buffer memory of the input/output data, a CPU5 which functions as an instruction executing means and an input/ output replacing means to perform a control operation and to execute a fault detecting program, and a working memory 6 using an RAM. As a result, the conditions of a fault including a faulty input/output device, the input/output conditions under which a sequence fault is generated, etc. can be known definitely to perform a proper treatment for correction of the fault. |
