| 摘要 |
PURPOSE:To increase greatly the chances to transmit a speech sending signal of a communication circuit connected to an attendant board to said attendant board, by setting consecuitvely a channel to transmit the arrived speech sending signal of the communication circuit to the attendant board while the communication circuit to be called is selected. CONSTITUTION:A central processor CPU detects via an operator circuit OPT and a received signal memory RSM that an operator has operated the digit buttons on an attendant board ATT and then selected the 1st digit of an extension number to be called. Thus a channel P1 set within a time division network TDNW is held as it is, and only a channel P2 is released. At the same time, a new channel P3 is set. The speech sending signal given from a trunk line CL is consecutively transmitted to the attendant board ATT via the channel P1. However, the speech sending signal given from the ATT is not tansmitted to the line CL. Then a holding tone SPT is transmitted to the line CL via the channel P3. |
