| 摘要 |
PURPOSE:To detect a fault of a storage device in its early stage and to improve the reliability by diagnosing the fault of the storage device by utilizing the free time of the storage device. CONSTITUTION:A fault diagnostic device 6 is provided with a readout control generating mechanism and an address signal generating mechanism and supplies a readout control signal to a controller 3 in a free time and an address signal which varies in order. This address signal is varied from the starting address to the ending address of the storage device 5 in order over the entire storage area and then returned from the ending address to the starting address to vary cyclically. When the free time of the storage device 5 and in the middle of the address variation, the fault diagnostic device 6 stops operating and the current value is held as the address signal; and the next address signal is generated when the device restarts operating in the next free time. The controller 3 performs the same operation as operation to a signal supplied from a CPU1 when the readout control signal and address signal are supplied from the fault diagnostic device 6, and detects a code error when the error occurs to display it on a fault display device 8. |
