| 摘要 |
PURPOSE:To perform the transmission of the pseudo carrier information without giving an effect to the transmission of data. CONSTITUTION:The data is transmitted to an RD line 22 through a high-speed circuit from an SD line 1 between a channel A of an MODEMa and a channel A of an MODEMb. The pseudo carrier information is produced by turning on and off an RS signal 2 of the MODEMa, and the signal 2 reaches the MODEMb through a data line to turn on and off a CD signal 23. For the MODEMb the ON/OFF of the signal 23 is controlled by a pseudo carrier signal and the OFF of signal of the high-speed circuit. The signal RD is clamped since no data is assured when the signal CD of the high-speed circuit is cut off. While the signal RD is not clamped when the pseudo carrier is turned off by regarding that no fault arises to the data. |
