| 摘要 |
PURPOSE:To detect the state change of a slave station immediately by a master station if any state change takes palce in the slave station by setting an incomming circuit of dial/ringer signal to the master station, inputting directly to a signal detecting circuit in a processor to make the master station request a polling request. CONSTITUTION:If any state change is generated in the slave station 2, its monitor controller 4 makes the dial signal significant and requests a polling to a master station 1 via a dial signal line 16. The ringer signal on the incoming line (m)(m=1-n) connecting the said slave station is made significant at the master station 1. Since a signal detecting circuit 17 of the master station 1 detects always the signal state of the incoming lines 1-n, when the signal state change is detected, the processor 11 stops the polling to the other slave station during execution, and the polling is performed by being jumped to a slave station 2 connecting an incoming line (m) with signijficant ringer signal. Then, the slave station 2 receives it and transfers data to the master station 1. |
