| 摘要 |
PURPOSE:To realize incoming service during a call, conference calling service, etc., with the same constitution by selecting and supplying one of signals including a sound on the basis of a command from a processor to a conference talking circuit and then by selecting and outputting it. CONSTITUTION:One of sound IN, dial tone DT and no-tone NT including an input signal from a time-division channel is selected by selecting circuit SEL-IN on the basis of control information from a processor and then supplied to conference talking circuits CF0 and CF1. Further, one of a selective input to them, the outputs of conference talking circuits and no-tone NT selected by selecting circuit SEL-OUT and outputted. As a result, the efficiency of the utilization of a highway is improved and a variety of services can be offered without lowering the multiplicity of a trunk unit. |
