Engaging central office set in PBX installation - uses central control, triggered by first or second instruction, releasing internal terminal on office set engagement

摘要

The PBX has a central control (ZR) and a memory (SP CNFG, CNCP) for installation configuration data and connection state information. The installation has at least one office set, with the central control testing the state of the office set terminals (TR1 - n) under trigger of a terminal engagement requirement. Thus it transmits a first instruction of a first internal terminal (T1) for the above mentioned testing. If the central control does not find a free terminal set, it transmits a special current to the unsuccessful terminal. The central control, triggered by a first or a second instruction of the first internal terminal, releases an engaged terminal set (TR1) and allocates it to the first internal terminal. USE/ADVANTAGE - For additional functions of a telephone PBX, with a facility of utilising free PBX terminals without time limitation.