Centrally controlled telephone exchange - allows both pulse code or pushbutton selection subscriber apparatus to be used

摘要

The exchange has each subscriber appts. (TLN) connected via a coupling field (K) with a transmission device (AUE). This is connected to a line matching set (AV) for connection to the connection trunk (HAL) via a selection supplementing device (WZE) with connection lines each coupled to a selection control device (WKE) and which provide selection tones indicating the state of the connection line. The selection supplementing devices (WZE) are each coupled to the transmission device (SE), the code receiver (CE) and the selection converter (WU)as well as the central selection information evaluation device (WAE). The transmission device (AUE) and/or the line matching set (AV) is coupled to the selection converter (WU).