Programmable operating mode selector in PBX - has central authorisation store in which selected mode is modified by additional code characters

摘要

The selecting circuit (SS, MKL) controls the authorised subscriber operating mode through the subscriber connection. The mode selected is indicated by an acknowledgement signal before the dialling signals are transmtted. When a connection is terminated the subscriber is switched to the lowest operting mode by an overriding manual release of the selecting circuit. The selecting circuit transmits additional code pulses dependent on the cradle switch contacts (11, 12, 13) and its own contacts (S11 .... S42, A, B, C) and together with the authorisation store controls a blocking unit. The selecting circuit can consist of key switches, a magnetic card reader or other data carrier which are reprogrammable with minimal wiring costs.