| 摘要 |
PURPOSE:To eliminate the need for intermission of connection between telephone sets and lines on emergency by using a telephone set interface so as to switch emergently lines to a specific terminals of an electronic exchange with an external command or the like at system fault. CONSTITUTION:A switch 21 of a machine room 16 is closed on emergency to transmit an emergency switch signal to a line processor 17, an emergency relay (EM)18 is activated to switch a relay contact (em) of a talking set and a channel signal is given to an emergency cord board 15, fed to an attendant board 14 via a capacitor C, a signal distribution relay B is activated for incoming display. Then the line processor is controlled by an external command, and a response/holding signal and a re-transmission signal outputted so far from an attendant board controller 12 to the attendant board 14 is fed to the attendant board 14 via the board 15. |
