| 摘要 |
PURPOSE:To confirm the vacant or busy state with a simple constitution, by providing the extension busy confirming key with the attendant board, starting the common control unit with the operation with the extension selection key, and dispalying the state of busy or vacant extension telephone units on the attendant board. CONSTITUTION:The extention busy confirming key which requests the identification of extension vacant or bury state is provided on the attendant board ATT of the extension exchanger, and the common control unit M is started from the position equipment POS through the operation with the extension selection key setting the extension number. Thus, the busy or vacant state of the extension telephone set SUB is displayed on the attendant board ATT to confirm the vacant state with the simple constitution. |
