| 摘要 |
PURPOSE:To replace a defective electronic device only by designing the diagnostic device that a fault of a unit having an output/input device as an interface with other system is diagnosed automonously. CONSTITUTION:When it is supposed that a diagnostic switch 32 is turned on, a short-circuit switch 33 is turned on accordingly to make an output circuit 15 to on-state for a prescribed time only. Then the response state of an input circuit 16 is discriminated and when the said input circuit 16 is turned on in response to the on-state of the said output circuit 15, the corresponding keyboard unit 31 is discriminated as normal, and after all indicators 13a, 13b are lighted for a prescribed time, the system is restored to the normal operating state. On the other hand, when the input circuit 16 is not in on-state, the keyboard unit 31 is discriminatwed to be faulty, the indicators 13a, 13b are not lighted and the faulty state is informed to the operator. |
