| 摘要 |
A telecommunications exchange includes line identification apparatus in which signals on additional wires (the 'p' wires) (1) which are switched in parallel with the speech pairs are used to identify an originating exchange line circuit. On detection of seizure of the 'p' wire (1) at one of a number of call logging points (11) a data signal is transmitted by a transmitter circuit (9). On detection of such a signal a receive circuit (2) adds a plurality of data bits to the signal identifying one of a number of associated 'p' wires (1) on which the signal was received and transmits the modified data signal to a receiver multiplexer (4, 4'). On receipt of the modified data signal the receiver multiplexer (4, 4') adds a respective plurality of data bits to the signal identifying one of a plurality of receivers (2) connected thereto and retransmits the signal to a further multiplexer (5, 5'). The further multiplexer (5, 5') adds a respective plurality of bits and transmits the signal to a control circuit (6, 6') which adds further bits identifying the further multiplexer (5, 5'). The complete signal is then transmitted to call logging apparatus.
|
