| 摘要 |
PROBLEM TO BE SOLVED: To detect an occurrence of an abnormal phenomenon and to quickly analyze a cause of a failure by using a means which accumulates the frequency of abnormality occurrence in failure diagnosing results for every failure diagnostic item and a means which stores and reads out the accumulated value. SOLUTION: A CPU 7 switches an input signal switching circuit 5 to a failure diagnosing signal 1 of a diagnostic item 1. The signal 1 is converted into a digital signal by an A/D converter 6 after passing the circuit 5 and then read by the CPU 7. The CPU 7 checks whether the A/D conversion value of the signal 1 is included in a prescribed range. If the conversion value is not included in the prescribed range, the occurrence of abnormality is diagnosed. Thus, the CPU 7 displays via a character generation circuit 10 on a monitor 11 in characters that the diagnostic result of the item 1 is abnormal. The CPU 7 also adds 1 to the value of an abnormality occurrence frequency accumulation value storage area of the item 1 which is stored in a RAM 8. The same procedure is carried out also for failure diagnostic items 2, 3 and 4 respectively. When a switch 12 is depressed with respect to the CPU 7, the accumulated value of abnormality occurrence frequency for items 1 to 4 are displayed in characters on the monitor. |
