| 摘要 |
PURPOSE:To make input/output operation continuously even though a failure occurs to peripheral devices during the operation, by starting the input/output operation basing on the first-in control action while reserving the last-in control action at the input/output (I/O) device. CONSTITUTION:By I/O start-up 5, 6 simultaneously ordered from CPU1 to plural peripheral devices 2,3, the same control action is taken at the plural peripheral devices 2, 3. At an I/O device 4, I/O operation is done basing on the first-in control action out of the plural control actions, and last-in control actions are reserved. When any abnormality is found in the data sent from the peripheral devices, 2, 3 or any abnormality is found in the control action of the peripheral devices 2, 3 during the operation, the I/O device 4 informs the abnormal device of the suspension of the I/O action. And, the I/O action is done through peripheral devices at which re-execution of I/O action is reserved. |
