| 摘要 |
PURPOSE:To make it possible that the system escapes from false synchronization, by hunting forcedly frame synchronization again when multiframe synchronization is not led in for a prescribed time after the establishment time of main frame synchronization. CONSTITUTION:The system enters to false synchronization at time (3). The re- hunting circuit which is a delay switching circuit is set at time (3). After fixed time T, the re-hunting circuit outputs a clear pulse to erase contents of the 5-bit register. Here, time T is selected longer than the time between signal frame synchronization leading-in times (5)-(7). As a result, hunting of the terminal station frame synchronous circuit is caused forcedly, and the system is escaped from false synchronization. |
