| 摘要 |
PURPOSE:To easily discriminate a key telephone that is ringing with a trunk line incoming, by producing the incoming tones different with each key telephone set in case the trunk line is displayed at its incoming with each key telephone. CONSTITUTION:The terminals B and B0 are connected for a key telephone No1TEL, and the incoming is displayed for all trunk line circuits No1COT, No2COT-. The terminals B and B1 are connected for a key telephone No2TEL, and the incoming of the No1COT is displayed. The terminals B and B2 are connected for a key telephone No3TEL, and the incoming of the No2COT is displayed. When the No1COT has the incoming, the No1TEL is connected to the No2TEL via a main device. In this case, the different tones are produced from the trunk line incoming sound sources C0 and G1 for the No1TEL and the No2TEL, and an audible display is given. The No3TEL, however, has no ringing. |
