| 摘要 |
PURPOSE:To prevent the breakdown of a system even at a failure of outgoing transmission of a master station by using in common a cyclic transmission from all slave stations to the master station and polling from the master station to the slave stations. CONSTITUTION:The cyclic transmission is attained from incoming transmission sections 12-N2 from slave station transmitters 1-N toward a master station transmitter 10. This transmission information is transmitted to a line changeover section 103 of the device 10. On the other hand, a selecting signal is transmitted to a designated slave station by using an outgoing transmission section 101 in the device 10. The slave station selected at that time interrupts once a stationary transmission frame being transmitted continuously and transmits an incoming word cyclicly as the stationary transmission frame by taking newly a synchronizing word as a head from that point of time. If the transmission section 101 is failed, since the incoming information is transmitted cyclicly to a switching section 103 asynchronizingly, the synchronizing word is detected from the incoming information after line switching and the incoming information is grasped by the receiving operation synchronizingly afterward. |
