| 摘要 |
PURPOSE:To display a busy extension at every subscriber circuit without increasing the load of a central control unit by providing a busy extension display information returning means on an electronic exchange independent of the central control unit. CONSTITUTION:When the call of a telephone set 80 and restoration information are detected in a subscriber circuit 10, a subscriber circuit control part 102 activates a busy information transmitting circuit 100 and transmits busy information to a busy extension display controller 5. It generates the busy extension display information with use of said information, said subscriber containing position information in a temporary storage memory 50 and extension number information, and returns the generated information to the control part 102. Consequently said part 102 causes a display lamp 103 to display the busy information. Thus a central control unit 6 need not display and control the busy extension. |
