| 摘要 |
PURPOSE:To detect a position where a fault occurs, by transmitting the address of a terminal station to a center station when an input signal does not come to the terminal station on a loop line. CONSTITUTION:When a fault occurs in a terminal station 2-(i-1), an input signal does not come to a terminal station 2-i. An input detecting part 23i discriminates the absence of the input and reports it to a terminal station control part 21i-1 to transmit its own station address. In a terminal station 2-(i+1) and following stations, the address signal passes through as an input as it is. When receiving the address signal, a central control station 1 specifies the position of fault occurrence and controls switches through terminal stations to change connections of lines by the by-pass system or the loop-back system, thus recovering the fault. |
