| 摘要 |
PURPOSE:To enable pseudo-transmitting and receiving of control signals and picture signals proper to facsimile service by providing a function to send a start signal of picture signal sending to subscriber's facsimile terminal at the time of completion of receiving of a facsimile terminal changeover signal during a pseudo-call transmitting test. CONSTITUTION:A pseudo-call generating device of a trunk exchange that absorbed subscriber's facsimile service function is made up of a control section 10, a picture signal sending and stopping signal control section 11, a tone detector 12, an MF signal mixer 13, an MF signal oscillator 14, a 4-line-2-line conversion circuit 15, an outgoing trunk circuit 16, an incoming trunk circuit 17 and channel changeover relays 18, 19. When receiving of facsimile terminal changeover signal is completed by the control section 10, the changeover relay 18 is operated to connect the facsimile terminal to the trunk exchange and a picture signal sending start signal is sent out from the control section 11. When communication is completed, the picture signal is sent by the control section 11 and transmitting and receiving of the picture signal is completed. |
