| 摘要 |
PURPOSE:To reduce the number of connection lines between data terminal line terminators by sampling the level of lines T and R in a speed, e.g., 10 times the data transmission speed, and transmitting alternately the information after the said sampling in a speed >= twice the sampling speed while putting plural bits together. CONSTITUTION:A level sampling circuit 1 samples the level state of the line R in a speed faster than the data transmission speed, e.g., 10 times in an interface converter CONV2 of the line terminator side. When a Manchester coding circuit 14 receives a transmission request, the circuit 14 transmits data to a line L in a speed being twice the sampling speed from a shift register 13, transmits a transmission end signal to a transmission direction control circuit 3 through a signal line 6 when the transmission of data is finished. When the data from the line L is received in an interface converter CONV1 at the data terminal device DTE side waiting for the reception from the CONV2 at the data terminal DTE side, the data is inputted to a Manchester decoding circuit 15 and transmitted to a shift register 16 after decoding. Thus, the data terminal line terminators are connected by a couple of lines in realizing the data exchange system or the like connecting the DTE in accordance with the interface protocol of the CCITT recommendations X.20. |
