| 摘要 |
PURPOSE:To eliminate wrong diaanoses, by stopping the operation of an input- output buffer circuit by means of the output of a resetting circuit which generates an output for a prescribed time from the moment when a diagnostic device is connected to a main device until the operation of the input-output circuit is stabilized by the power source. CONSTITUTION:When a fault diagnosing device 2 is connected against a main device 1 as shown in the figure, operations of an input-output buffer circuit 20 are stopped for a prescribed time by the output signal of a resetting circuit 21. When the prescribed time has passed and the supply voltage is stabilized thereafter, the resetting circuit 21 does not produce any output and the input- output buffer circuit 20 starts operations. As a result, CPU11 starts normal operations. The diagnostic device 2 starts fault diagnoses from this moment. Therefore, the device can perform diagnoses without wrong diagnoses. |
