Calling line tracing system and identification detector.

摘要

A calling line tracing system and identification detector arranged for identifying the identity number of a calling station connected through one or a series of switching exchanges (9) to a called station in any type of telephone network. The identification system is started automatically whenever a telephone exchange (9) receives a call addressed to a local line designated with a special category or shunt. The local exchange (9), once the special category or shunt of the addressed line is sensed, automatically starts a change in the signalling sequence and disengages its control unit from the calling process, passing the control of the telephone call to the identification detector which is coupled to the addressed line, The identification detector starts a signalling process with the telephone exchange where the call originated to obtain all available information at that exchange about the calling telephone station. Once all available information has been received and entered in the memory (4) of the detector, the calling process is completed in the normal way. The calling station identity information is shown on a display panel (6) or stored in the detector memory (4) for later retrieval.