| 摘要 |
PURPOSE:To offer a voice picture information exchange service without limit of connection to other station even at system stop by allowing a telephone set to make call and incoming call and forming a function to be reconnected to picture transmission and picture reception device as required independently of system exchange processing. CONSTITUTION:A terminal switching controller 10 is provided so as to provide an abnormality system detour function also to a terminal device except a telephone set. When an exchange system 13 stops operation, a line switch device 11 draws a relay line 15 to the controller 10. The controller 10 supervises always the incoming of monitor circuit 5, 6. In making a call, a KEY of each acoommodating terminal is operated and its information is relayed to a main control circuit 3 by a KEYCONT8. The circuit 3 turns on a corresponding analog switch 1 via a gate control circuit 2. Thus, the relay line and the said terminal device are connected directly. The calling information is supervised similarly as above, and the relay line and the terminal device are cut off similarly as above by re-operating the key corresponding to the said terminal device. The relay line and the telephone set are connected similarly at the incoming call from the relay line 15. The controller 10 has an independent control circuit and a power supply. |
