| 摘要 |
PURPOSE:To eliminate ineffective exchange processing at calling by a group variable abbreviated dial by displaying the presence or absence of call connection corresponding to an abbreviated dial number and identifying a busy state of a called party when a selected abbreviated dial number is received. CONSTITUTION:Abbreviated dial numbers to all opposite subscribers after registration from a variable abbreviated dial group G1, and operating display codes F are stored to a group variable abbreviated dial data 10 in addition to the telephone numbers. The operating display code F is set normally to a logical ''0'' and the corresponding opposite subscriber is selected and connected by an abbreviated dial number Cd, and set to logical ''1''. When an opposite subscriber D selected and connected by the extension A by using the abbreviated dial number Cd is selected by the extension B by using the abbreviated dial number Cd, a central controller CC1 referencing the group variable abbreviated dial data 10 discriminates immediately that the opposite subscriber D is busy by using the operating display code F and a busy tone is returned from a signal tone trunk TNT1 in a station M. |
