Circuit arrangement for tracing or identifying connections in digital time division multiplex telecommunications systems, in particular telephone systems, with a dialling receiver which can be connected to a plurality of subscriber connection circuits for audio-frequency code dialling signals, in particular push-button dialling signals

摘要

Circuit arrangement for tracing or identifying connections in digital time division multiplex telecommunications systems, in particular telephone systems, with a dialling receiver which can be connected to a plurality of subscriber connection circuits for audio-frequency code dialling signals, in particular push-button dialling signals. A push-button dialling receiver (CR) can be switched over to an operating mode as a call trace dialling receiver in which it is assigned to a calling subscriber with tracing authorisation and responds to call trace dialling signals only. A speech protection circuit which is effective in normal operation is initially disabled. IMAGE