| 摘要 |
In an information transmission system, in particular a telephone system, the subscribers can be connected to a dial exchange over a line. At the dial exchange end and at the subscriber end of the line are connected bidirectional multiplexers or demultiplexers over a bidirectional modem circuit which modulates and demodulates the data according to the intended transmission. If required, bidirectional compressor and decompressor circuits are connected to the multiplexers and demultiplexers, to which the subscribers are connected through a forward and a backward channel and a SLAC (bidirectional analog-digital converter (CODEC) with subscriber interface circuits (SLIC)), or to which a relaying device of the dial exchange is connected through drive circuits. In order to allow fault finding to be carried out in a simple manner in such a system, a measuring, regulating or controlling circuit (33, 34, 36, 37, 38) is arranged between each subscriber (1) and their allocated CODEC's, SLIC's or SLAC's (2) or is at least partially integrated into said CODEC's, SLIC's, SLAC's. |
