Subscriber line signalling device for use in a telecommunications system

摘要

The subscriber line signalling device (D) is employed in a digital telecommunications system. In particular the device (D) is used in a subscriber line interface module and it allows all signalling data to be detected and generated on a per-channel basis. A microprocessor (A) controls the device which generates and detects cyclically permutable code words on a plurality of traffic channel paths to or from the device. It is arranged that each generated cyclically permutable code word on any one traffic channel path is synchronously coded with respect to any other traffic channel path. The device can also be programmed to handle different data rates. In addition the operational modes of the traffic channels can be controlled giving loopback facilities allowing cyclically permutable code words to be generated and detected from the input and output traffic channels as desired and allow a diagnostic facility to be implemented.