| 摘要 |
PURPOSE:To check the occurrence of a hang-up state by providing a counter step advanced on the execution of every prescribed processing unit, and allowing each utilization source to read the value of the counter. CONSTITUTION:The control part 6 of a disk pack device 5 is provided with a counter 8 step-advanced on the execution of every prescribed processing unit, and while the CPU1 of a system A uses the disk pack device 5, a busy signal is sent back for access from the CPU of a system B. When the busy signal is returned continuously even a certain time later, the contents of the counter 8 are read. Even if the busy signal is returned for reaccess, the contents of the counter 8 are read again. When those read values are different, it is judged that the CPU uses it continuously and when they are equal, it is judged that the system A has a fault, thereby connecting the system B while forcibly releasing the system A. |
