| 摘要 |
PURPOSE:To realize the transmission of the disconnect signal, by connecting the signal transmitting relay contact in series to the signal receiving relay contact of a trunk device to use them as a signal transmission line to a called subscriber side and accordingly detecting the completing signal even while the restart processing is executed. CONSTITUTION:A signal transmitting relay contact s0 deg. to the called subscriber side is connected in series to a signal receiving relay contact r11 of a trunk device that performs a connection of call. These connected contacts are used as a signal transmission line SSO to the called subscriber side. Thus the signal transmission lines SS0 and SS1 to the called and calling subscriber sides respectively transmit the earth under the state of connection of call. Under such conditions, the talking is held although the restart process is executed owing to a fault of the switchboard. When the speech end signal is transmitted from the calling subscriber, a signal transmission line SR1 is opened to inhibit the working of a relay R1. Accordingly, the speech end signal can be received. Furthermore the line SS0 is opened, and accordingly the disconnet signal can be transmitted to the called subscriber side. |
