| 摘要 |
PURPOSE:To restore forcibly a telephone set where the busy state is to be continued by transmitting a hook on signal to a common line by manual operation independently of hook-on to each telephone set. CONSTITUTION:A switch 10 operated manually externally is provided to a transmitter 11, and when the switch 10 is operated, the transmitter 11 is started and a combination signal corresponding to the hook on signal is transmitted to a common line 5. When the telephone set remains busy, the busy state is released by allowing the telephone set to transmit forcibly the hook on signal and the mode is restored to the standby state possible for talking request. |
