| 摘要 |
<p>A PCM transmission link system is provided with a fault location network for detecting faults in regenerators arranged between terminals in both transmission directions. All amplifiers in each of the regenerators are connected to a band-pass filter with a pass frequency allocated to the respective regenerator. Only every second terminal is provided with a fault location device while the other terminals are provided with pulse train converters. The fault location is connected to one of the links outgoing from the fault location terminal and produces pulse trios and pulse duos for fault location in the outgoing and incoming transmission direction, respectively. The pulse train converters receive the pulse duos and converts them to pulse trios. Pulse trios produced by a pulse train converter are transferred on links incoming to the fault location terminal. The trio pulse trains, both on the outgoing and on the incoming links, contain as a frequency component one of the pass frequencies which is filtered out by the aid of a respective filter. An obtained sinusoidal pass frequency signal shows that no fault exists in the supervised transmission direction up to the respective regnerator.</p> |
