| 摘要 |
PURPOSE:To offer a transmission line switching system, in which a fault, extending over all sections of the transmission line, can be quickly confirmed by transmitting the signal of a transmission line, now being used, to the transmission line of a preliminary side as well in parallel from a transmission terminal, and detecting the code error of the signal, after being decoded at a reception terminal. CONSTITUTION:The signal, transmitted from an intra-office transmission line, is transmitted to both the transmission line of a system, now being used, and the transmission line of the preliminary system, in parallel, by a signal branch circuit 9. At the reception terminal, the signal, transmitted through the preliminary system transmission line, is decoded and inputted to a monitoring equipment 5 through a switching device 6. The monitoring equipment 5 detects a code error signal (e.g., parity bit), inserted by a multiplexing equipment 4, and decides whether the transmission line is normal or not. In this application example, a one-way transmission was explained, but this invention can be applied even for a two-way transmission line. |
