| 摘要 |
PURPOSE:To perform both the input and output processes with use of just a single IO controller by using a selector to switch two addresses. CONSTITUTION:Addresses 9a and 9b are set in an output mode and an input mode respectively. A remote process IO terminal 3a selects the address 9a and an IO mode set 10a in an initialization mode. A CPU 4 reads the data corresponding to the address 9a out of an IO data memory 6 and transmits a selection command to the address 9a. The terminal 3 is set in a waiting mode for output data when the coincidence is obtained between both addresses. The output data sent from the CPU 4 is transmitted to the process side. The end of this transmission is informed to the CPU 4. Then the terminal 3 itself selects the address 9b of an input mode and an IO mode set IOb. A serial IO controller 5 transmits a selection command to be sent to the address 9b to a remote process IO terminal 3b. Then the terminal 3b is set in a waiting mode for the input given from the process after the coincidence is secured again between both addresses.
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