| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique by causing no malfunction even when noises out of a specification range unabsorbable by hardware, are superposed in a programmable controller. SOLUTION: A loop back system of a noise detection signal is formed. In the loop back system, the noise detection signal, such as an analogue ON/OFF signal, energizing a noise detecting means is converted into a digital signal. Based on the digital signal, it is determined whether predetermined states set in advance can be recognized including a first state such as the ON state of the noise detection signal and a second state such as the OFF state. When it is determined that the recognition of the predetermined states is impossible, the noise detection signal of a noise detection means is regarded as being superposed with a noise at a level out of an acceptable range, and the output of a sequence control signal to a noise source part corresponding to the noise detection means is stopped or the noise source part is detached from a sequence control system. COPYRIGHT: (C)2004,JPO&NCIPI
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