| 摘要 |
PURPOSE:To select another line with the same channel access button after a holding operation by setting the holding state of a line with a port button other than channel access buttons. CONSTITUTION:When the server of a telephone set A depresses an idle port button, a device CC detects this depression and holds a trunk line C/OC, through which the telephone set A calls, by a trunk COTC and opens a channel (a). In such a state, the device CC extinguishes the indicator lamp of the channel access button and displays this holding state on an indicator lamp corresponding to the port button. If a telephone set B depresses a port button of common display to respond to this state, the indicator lamp corresponding to this port button is changed from the holding state to the call indicating state. Meanwhile, the channel access button of the telephone set A is released from the trunk line C/OC, and the selection of another trunk line is made possible thereafter. |
