| 摘要 |
PURPOSE:To eliminate the faults which are generated when a power supply is turned on and difficult to be analyzed and to ensure an automatic recovery of a diagnosing device, by switching off the power supply temporarily and then switching it on again in case a fault is detected when the power supply is switched on for the diagnosing device which performs a diagnosis after the power supply is switched on. CONSTITUTION:A power supply control part 6 controls the ON/OFF signals G1 and G2 by the ON/OFF signals C1 and C2 sent from an operation part 3 as well as an error signal F sent from a control part 1. When a power supply part 2 is turned on, the output voltage B is delivered to each part. Then the part 1 reads an initial control program including a diagnosis program out of an inside ROM and starts execution of it. The part 1 checks a defect or nondefect state for a microprocessor 11, the parts of a memory 12 excluding a read-only part and interfaces D and E respectively. Then the operation proceeds to the next step when no defect is detected. While the power supply is temporarily switched off G2 by the signal F and then switched on G1 again after a fixed time if any defect is detected. Thus, the faults which are easily generated when the power supply is switched on are avoided and an automatic recovery of a diagnosing device is ensured. |
