| 摘要 |
PURPOSE:To obtain the optimum line concentration system by simplifying the control circuit by means of the delay circuit. CONSTITUTION:When the subscriber SUBO takes up the receiver, scanning circuit SCNO is actuated. And scanning control circuit SCNCONT of the master station detects the state change of SUBO via scanning line SCNL. The control unit in the master station detects the call of SUBO via SCNCONT to select idle trunk line TLO as well as to control switch control circuit SWCONT for connection between SUBO and TLO. Then SWCONT transmits the signal to switch driving circuit DIVO via driving line DIVL to close contact xp00. In this case, the delay circuit is inserted to SCNL in the same number as the scanning spots, so the scanning |
