| 摘要 |
PURPOSE:To reduce the load of a high-order device and to improve an information processing system, by using a substitute control adaptor to accept actuation although the control adaptor of one side has a fault. CONSTITUTION:When detecting the abnormal completion through a low-order interface circuit 24, an error detecting circuit 23 reports this completion to a high-order device 1 from a high-order interface circuit 21 and through an error reporting circuit 22. At the same time, an error counting circuit 28 counts the error generating frequencies. When the count value of the counter 28 exceeds a prescribed level, it is decided that the recovery is impossible for the fault of a control adaptor A3. Thus an adaptor switching circuit 27 is actuated, and a control adaptor B selecting circuit 26 selects a control adaptor B4 and a driver 5 through a low-order interface circuit 24. |
