| 摘要 |
PURPOSE:To increase the ability of processing by avoiding the interruption to CPU from the communication control unit, through the response transferred to CPU to be moved to the next polling and through the request of the next automatic instruction when the polling data is processed for a given length. CONSTITUTION:The automatic polling command register 3 performs temporal memory by receiving the automatic polling instruction from CPU, the automatic polling command control section 4 fetches the polling data from CPU every station while the automatic polling command is present in the register 3 and transfers it to each station via the transmission line 10. Further, the response from each station is fetched from the reception line 11, and if it is transferred to CPU, it is transferred to CPU and the automatic polling instruction is taken over to the read command. If it is not transferred to CPU, it is transferred to the polling of the next secondary station. When the polling data is processed for a given length, the next automatic instruction is requested. Thus, the interruption from the communication control unit to CPU is avoided to increase the ability for processing. |
