| 摘要 |
PURPOSE:To display a caller number, a caller name and degree of emergency to a incoming telephone set, by providing a signal other than a selection signal to a signal transmitted and received between the telephone set and an exchange at calling. CONSTITUTION:A control signal representing the name of caller and degree of emergency, and a selecting signal are transmitted to an incoming side exchange 4 via a calling side exchange 3 with the dial operation of a digital telphone set 1. The exchange 4 interpretes a received dialed signal, selects the line of an incoming side telephone set 1' and transmits the control signal including a call signal to the telephone set 1' to a signal control circuit 6' via a multiplex and separation circuit 2'. Thus, the control signal is given to the telephone set 1' in the prescribed order and number of digits, and a call tone of the incoming telephone set 1 rings, and the call number, the name of caller and the degree of emergency are displayed on a display. |
