| 摘要 |
PURPOSE:To reduce the insertion loss due to interruption and to prevent the effect of an interference data terminal on a subscriber, by inserting a monitor amplifier to a subscriber terminal to be tested with the status information of the subscriber, before a line test trunk is connected to the subscriber terminal. CONSTITUTION:When a telephone number of a subscriber to be tested is dialed from a test board LTF, the number is received at a control circuit of an exchange via a line test trunk LTTA, the status information of the corresponding subscriber is transmitted to the line test trunk LTTA and displayed on the LFT. In case of a busy call, a relay MON of an accessory unit LTTAU is activated through an operating contact ''by'' of the relay of the trunk LTTA, and a monitor amplifier MNAMP is inserted to the subscriber line. Further, the controller of the exchange closes links 3, 4 between the subscriber terminal and the unit LTTAU after the transmission of busy information. Thus, a test personnel can monitor the line without giving adverse effect on other subscribers. |
