| 摘要 |
PURPOSE:To improve the reliability of a transmission enable signal transmitted to the own terminal by receiving a response signal from an opposite line terminating device and transmitting the transmission enable signal to the own terminal in a line terminating device received, a transmission request signal. CONSTITUTION:When the line terminating device DCE1 receives the transmission request signal from a digital terminal DTE1, the device DCE1 transmits digital transmission information SG to the line terminating device DCE2 via an exchange NW. The line terminating device DCE2 is provided with a signal receiving converter SRT and when the transmission information SG to the terminal DTE2 is received, a carry detecting signal CD representing the reception is transmitted to the terminal DTE2 and a signal in a signal bit S0 in the received information SG is inserted to a signal bit S1 of the returned information SG' and this signal is transmitted back to the transmission terminal DET1. The line terminating device DCE1 detects that the signal bit S1 is logical 1, generates the transmission enable signal CS and the signal CS is transmitted to the terminal DTE1. |
