Engaging central office set in PBX installation - involves two tests, and during second one central office determining free terminal to be used

摘要

The PBX terminal set engagement testing uses a central control (ZR) with a memory (SP CNFG, CNCT) for the installation configuration, data, and for connection state information signals. The central control is triggered by an engagement segment from a terminal (T1) for testing the state of the office sets (TR1-n). - After the central control triggering by a first, or second, instruction of the terminal, it tests the PBX installation, according to a preset criterion, for its free state, possibly w.r.t. a second terminal (12) coupled to the respective office set. On a positive result of the second test, the central office couples the first terminal to the second one, with release of the first office set (TR1).