| 摘要 |
PURPOSE:To prevent inconvenience due to RD noise, by delaying the of timing of a transmission request signal <= one character time in a MODEM. CONSTITUTION:When a transmission request signal RS-ON is applied to a terminal 6, the outouf of a receiver circuit 7 is at ''L'' and a signal RS' of a control line 9 is at ''H''. A transmission line 8 transmits a transmission carrier CARR when the control line 9 is at ''H''. On the other hand, an output of the receiver circuit 7 is applied to delay circuits 10, 11, the delay circuit 10 is not in response to a trailing signal, but the circuit 11 responds only to the trailing signal to output a signal with a delay of t1. Thus, a transmission enable signal CS is transmitted to a terminal 13 with the delay of t1. Next, when the transmission request signal RS-On is applied to the terminal 6, since the output of the circuit 7 rises, the output of the circuit 10 keeps ''L'' for t2 and changes to ''H'' afterward. Thus, the signal RS' of the control line 9 is OFF after the time t2 when the RS is OFF and the transmission carrier CARR is stopped. |
