| 摘要 |
PURPOSE:To improve the reliability of data transmission reception by allowing a reception terminal device to cause an off-state to a carrier detection signal (CD) after data reception is finished. CONSTITUTION:When a request (RS) signal of a transmission terminal device is transmitted via a line 7 through a digital exchange system network, the CD signal is generated from an OR gate 8, the said CD signal is transmitted to the reception terminal device and the data is transmitted to the reception terminal device from a data transmission reception device 2 via a data reception line 5. Even when the data transmission is finished and the RS signal on the line is lost, so long as data transmission reception device 2 of a DCE1 is not transmitted to the reception terminal device, the CD signal is not lost. The switching control of the CD signal from the ON to the OFF state is executed by NOR gates 9, 10 ANDing the OFF-state of the RS signal and the ON-state of an idle buffer (BE) signal.
|
