| 摘要 |
PURPOSE:To control the changing over a plurality of branched offices at the same time by chequing the transmitting line between a master station and the branched office, and by judging the operating status of the branched office side by a short time, by means of combining a simple signal and a mechanism which indicates the present operating status of the branched office to the master station side. CONSTITUTION:A branched office state sending command signal is sent by a master station signal sending part 12 for the purpose of informing the operating state of the branched office before the change-over on the branched side. The operating state of the branched side is sent to the master station side on the basis of the signal received by a branched office signal receiving part 15 on the branched office. The present state of the branched office is indicated by a state judging part 13 by means of receiving this signal on the master station side. Then, the master station sends an operation state changing-over command which is made by a signal making indicating part 11 to the branched office side. If a change-over control part 17 of the branched office may receive the change-over signal, the operating state of a branched office device body 18 is changed over, and at the same time, sends an operation state change command receive recognizing signal is sent to the master station. |
