| 摘要 |
PURPOSE:To realize multiple connection of the same kind of terminal devices, especially of multifunction telephone by providing specific intervals (frame) to a control signal transmitted/received by a private branch automatic exchange and terminal equipments. CONSTITUTION:A control signal SR1 sent from a private automatic branch exchange PABX1 to a terminal devices 5 or 5A through a terminal interface circuit 3 mainly controls the action of a lamp. And a signal SS1 is returned from a terminal equipment 5 or 5A to the circuit 3, mainly informing key information of the terminal device. These signals SR1 and SS1 make one pair and switched alternatively by each specific interval (frame). By such operation, a gate control circuit 10 in the terminal device 5 detects the signal synchronization of each one frame, and repeats the action of a connecting/disconnecting gate circuit 7 of terminal devices 5 and 5A. Namely, it becomes possible to make alternative transmission/reception between terminals 5, 5A and circuit 3 of PABX1, realizing multiple connection of the same kind of terminal devices, especially those of multifunction telephones.
|
