摘要 |
PURPOSE:To make it possible to discriminate between an outgoing call and incoming call by a master-station device, to simplify centralized service observation, and to improve the efficiency of the observation, by discriminating an outgoing or incoming call at a centralized observation branch station and by receiving and displaying the information on it at the master station. CONSTITUTION:Through the off-hook of a subscriber on an observation circuit, the connection operation of the automatic telephone switchboard advances and main link 2 is closed, so that the outgoing-incoming call discriminator will generate signals through the relay operation of observation unit 3. As a result, obervation common control unit 4 sends out outgoing-call information to master-station device 5 via an inter-office junction line and device 5 indicates the originating by lighting up a lamp. In addition, if an incoming call is generated to the observation circuit, unit 4 starts operation via unit 3 and the outgoing-incoming call discriminator before link 2 is held and, conseguently,incoming discrimination information is sent to device 5, so that the lamp will come on. |