| 摘要 |
PURPOSE:To obtain a simple and miniature B-board common unit by displaying main-wire numbers, etc., of main wires under connection on a display circuit while an operator is making connections and by alternately displaying the number of held incoming calls on the display circuit while not. CONSTITUTION:During the connection operation of an operator, FF30 becomes ''1'' and a main-wire number under the connection or extension number of an extension subscriber is displayed on display circuit 16. When the operator does not engage himself in any operation, FF30 becomes ''0'' and common unit 19 detects and counts the number of held incoming calls and supplies the result to AND circuit 31. As a result, circuit 31 and OR circuit 33 both become ''1'' to supply the number of held calls to data line 24 and its value is stored in data holding circuit 17 via AND circuit 18, so that the number of held calls will be displayed on circuit 16. |
