| 摘要 |
PURPOSE:To make it possible to automatically reset a base unit and a remote control unit at an initial state in case of an abnormal condition in a transmission circuit or a reception circuit, by providing an abnormal condition detecting circuit adapted to reset a microcomputer after a set period. CONSTITUTION:Abnormal-condition detecting circuits 15 and 35 monitor data transfer periods by always monitoring the output of receiving circuits 14 and 34 provided in a base unit 10 and a remote control unit 30-i respectively, and comparing the corresponding voltage of pulse period of reception data 17 and 37 outputted by the receiving circuits 14 and 34 with a reference level, thereby judging as to whether transmission-and-reception data transfer interval exceeds a set interval or not. When the former exceeds the latter, the state is judged as abnormal, reset signals 18 and 38 are outputted to imicrocomputers 11 and 31 respectively to reset them. |
