| 摘要 |
PURPOSE:To switch uninterruptibly a signal by using the 1st and 2nd write counters so to write the signal to memory on the basis of a frame position pulse, using only an output of a read counter synchronously with an output of the most significant digit of the write counter of the 1st route and reading the signal from the 1st and 2nd memories at the same time. CONSTITUTION:The signal inputted from a terminal IN is transmitted to, e.g., to routes 1 and 2 through a distributor to which a frame synchronizing pulse from a logical cirucit 4 at the transmission end of a station A is given. The signal inputted through two routes at the receiving end of a station B is subject to frame synchronism respectively at frame synchronism and the signal are transmitted respectively to corresponding memories 8, 9. Then the signal is written in the memories 8, 9 according to the frame location pulse respectively. When the route 1, e.g., is selected by a selection circuit, the signal written in the memories 8, 9 by a read pulse synchronously with the output of the write counter is detected and two coincident signals are inputted to a selection circuit 10. |
