| 摘要 |
PURPOSE:To change a machine number of an I/O without increasing an interface line, by selecting the I/O by an old identifier, then, changing a holding identifier in accordance with a data sent from a CPU side, when changing the holding identifier of the I/O. CONSTITUTION:When a channel CH 1 selects an I/O 2, a selecting signal and a physical machine number of the I/O 2 are put on a signal line 4. The selecting signal indicates a controlling circuit 101 to start the select-processing, and contents of a register GR 100 in which a data of the signal line 4 is stored are compared with a holding machine number of the I/O 2, which is stored in an RG 103, by a comparing circuit 104. In case of coincidence, a coincidence signal is supplied to the circuit 101, and the I/O 2 returns a response signal to the CH 1 through a signal line 5. When a change indication of a physical machine number of the I/O 2 is given to the CH 1 from a CPU, the circuit 101 transfers a new physical machine number data to an RG 102 from the RG 100 and checks it, and thereafter, returns an end signal to the CH 1 by use of an old machine number of the RG 103, also transfers contents of the RG 102 to the RG 103, then, the I/O 2 is selected by this machine number. |
