| 摘要 |
PURPOSE:To carry out the reorganization of a loop to eliminate a control line and to attain the common use of a control line MODEM, etc. with a data line, by transmitting a control instruction with address from a central controller via a loop transmission line in case a fault arises at a station. CONSTITUTION:A central control station 1 monitors and controls the loop transmission system, and the data is exchanged between stations 3a and 3b which are connected via a loop transmission line 2. The stations 3a and 3b deliver an instruction for branching in case a fault occurs at their own stations and they receive a by-pass command and then deliver an instruction for release of the branching when they receive a by-pass release command addressed to their own stations. Then segment branching devices 15a and 15b are connected to the stations 3a and 3b via a transmission line 2. Then the device 15a or 15b, when a branching instruction is delivered from the corresponding station, cuts off only the relevant station from the line 2 to give the by-pass to the station. Furthermore, the device 15a or 15b connects the corresponding station to the line 2 when a branch releasing instruction is delivered from the corresponding station. |
