| 摘要 |
PURPOSE:To enable the automatic callback even for other station subscribers, by transmitting the subscriber status request signal from the transmission station to the incoming station periodically, when automatic callback registration is present to the telephone sets of other station. CONSTITUTION:When the subscriber A dials the number of the telephone set 1B from the telephone set 1A and confirms busy tone, the telephone set 1A is hooked and the specific number for automaic callback and the telephone number of the subscriber B are dialed. This dial signal is received at the central controller 8A via the scanner 6A and registrated in the memory device 9A. The central controller 8A transmits the subscriber status request signal to the incoming station from the common line signal device 10A periodically. When the central controller 8B of the incoming station receives this signal, the subscriber status signal of the telephone set 1B is returned to the outgoing station. If the telephone set 1B is vacant, the central controller 8A makes call out connection of the telephone set 1A, allowing the connection with the telephone set 1B the same as normal outgoing connection. |
