| 摘要 |
This invention relates to a duplex loop type transmission system which is so constructed that a plurality of transmission stations are loop-connected with two transmission lines, and the control right for transmission is carried about among the transmission stations. When trouble, such as disconnection on the transmission lines is detected, the station having the control right is adapted to transmit a check signal to the transmission line on which the trouble is detected and the station which receives the check signal returns a response signal to the next station at the side from which the check signal has been transmitted, and the station which receives no response signal carries out a loop back, thereby enabling clearance of the trouble in a short time. |
