| 摘要 |
PURPOSE:To reduce the number of signal lines between a data terminal and a data switching network by synthesizing plural pairs of signal lines and then separating these signal lines again in the interface between the data terminal and data switching network. CONSTITUTION:A transmission data line T and a control line C from a terminal 1 having an X.21 interface are combined to a T' line in an interface device 3, then separated into respective information of the T line and C line of the X.21 interface again by an interface device 4 in a network terminating device 2. On the other hand, a receiving data line R to the terminal 1, an indication line I and a signal element clock line S are synthesized to an R' line by the device 4 in the device 2, separated again in the device 3 and then transmitted to the terminal 1. Therefore, the devices 3 and 2 are satisfactorily connected only by connecting the two pairs of signals lines T', R', and if the device 3 and the terminal 1 are arranged adjacently, the section connecting the five pairs of signal lines T, R, C, I and S requires no long distance. |
