| 摘要 |
PURPOSE:To quickly detect that the generation of a trouble is due to the noise by providing a means to detect that a prescribed number or above of noises are mixed between two regular external signals to occur continuously. CONSTITUTION:When an external input IS including an external signal SO and a noise N enters, a counter 11 counts the number of inputs of the external input IS. On the other hand, an external signal detecting processing means 12 executes the processing to detect the external signal SO from the external signal, and when the external signal SO is detected, the prescribed processing corresponding to the external signal is executed, and the counter 11 is reset. The detecting processing of the external signal SO and the noise can be executed by the double reading system. The counter 11, when the number of external inputs arrive at the prescribed number, outputs an external input abnormal signal SABN. |
