| 摘要 |
PURPOSE:To improve the utilizing efficiency of a line and a terminal device by supervising always the operating state of both terminals connected to a line acquired by a reservation registration, and cutting the line when the power supply of any other terminal is turned off. CONSTITUTION:A status signal 17 tocheck whether or not a power supply of video and sound terminal devices 7A, 7B is applied is outputted to line controllers 4 and 5 from both the devices. The line controllers 4 and 5 supervises the signal after the signal 17 is connected to the line and when the cut-off of one power supply of the said terminal device is detected by the signal 17, the controller 4 or 5 detecting it informs the end of use of the line to the controller 4 of a reservation control station 1 managing definitely the line management by using a supervisory signal 18. The controller 4 references the reservation schedule of the registration device 3 based on the signal 18 and after the completion of the use of line is confirmed, the controller 4 transmits a control signal 12 to the controller 5, both the controller output cut-off control commands 15A, 15B to switches 6A, 6B so as to open the line. |
