| 摘要 |
PURPOSE:To input many control signals for broadcast control with a simple input circuit and the less number of signal lines by providing a serial transmission means for transmitting and receiving data between the titled exchange and a broadcast controller and specifying the range for a broadcast sound output. CONSTITUTION:A central controller 21 in an exchange is microcomputerized, where a microcomputer package 17 and a serial I/O package 20 are connected by a data bus 22. The serial I/O package 20 is connected to a MODEM24 by an interface cable 23, and an input signal line 25 from the MODEM is connected to a broadcast controller. A broadcast controller 36, in broadcasting, outputs a sound signal to telephone exchanges 28 and 29 by using sound signal lines 37 and 38 and at the same time transfers broadcast control data to the serial transmission signal lines 32 and 33 through the MODEMs 34 and 35. The telephone exchanges 28 and 29 receive the control signal through the MODEMs 30 and 31 and transfers a broadcast sound to the corresponding subscriber telephones 26 and 27 in the district in correspondence to the contents of a signal. |
