| 摘要 |
PURPOSE:To reduce malfunctions and erroneous operations of switching extremely by providing a switching register consisting of an FF circuit to control I/O requests unificatively. CONSTITUTION:In respect to the control of the switching mode, when FF3 and FF4 are reset and I-system computer 1 and II-system computer 2 are down and the signal of manual switching operation board 3 is 0, the disable mode is set to accept no any switching request signals. Here, when manual mode switching signal SWN is input from operation board 3, FF4 is set to set the automatical mode. Next, when FF4 is reset and automatic mode request signal RQA1 is transmitted from computer 1, FF3 is set to set the automatical mode. The same operation is performed for computer 2. Next, in respect to the control of the connection state, when I-system connection signal SW1 becomes 1 in the manual mode, FF1 is set, and I/O devices are connected to the I system by switching unit 6. Here, when signal SW1 is set to 0, FF1 is reset to perform disconnection. Next, when signal SW2 is set to 1, FF2 is set to connect I/O devices to the II system. Here, SW2 is set to 0, and then, I/O devices are disconnected. |
