| 摘要 |
PURPOSE:To prevent the influence of trouble from extending to a multiplex transmission line by setting an elastic output to a logical value 1 forcibly unless there is the state transition of a signal on a transmission line from a terminal to a branching and inserting device for a specific time. CONSTITUTION:If trouble occurs on the terminal or a subscriber transmission line 7, the output signal (e) of a receiving buffer amplifier 19 has the logical value 1 and is written in an elastic store 23 at a period different from the period of an incoming-side up multiplex transmission line 2-1. Therefore, signals on the incoming-side up multiplex transmission line 2-1 are all passed through an AND gate 24 and sent out to an outgoing-side up multiplex transmission line 2-2, so that the influence of the trouble occurring on the terminal or up subscriber transmission line 7 is eliminated. |
