| 摘要 |
PURPOSE:To eliminate an EMA (fault processing) request due to a software bug by collating the series number of an input-output device with small-scale hardware by providing a central controller with a detecting circuit for the series number of the input-output device. CONSTITUTION:This describes access to input-output device IO101 attained by central controller CC100. In this case, CC100 sends out a signal, requesting IO101 to send its series number, to BUS 106 from IOD109 via signal line SIGA107. Simultaneously, the series-number data on IO101 are also sent out to BUS106. When the series number agrees with the received series-number data, IO101 sends out a response signal to CC100 via signal line SIGB108. On receiving the response signal, CC100 sends out a signal for a request to send data to SIG107 and, at the same time, sends a read instruction data to BUS106. |
