| 摘要 |
PURPOSE:To switch lines without a bit by providing a transmission buffer on a transmission side and a receiving buffer on a reception side and transmitting information through the transmission buffer to the lines after switching only at the time of switching the lines. CONSTITUTION:After line changeover devices 11 and 21 finish switching processing from lines 11a-21a to lines 11b-21b, the line changeover device 11 notifies a signal indicating the finish of the switching processing through a signal line 103 to a changeover control part 10, and the changeover control part 10 switches a switch 14 to 14b. Terminal information (transmission information) transmitted from a terminal 15 to a transmission side 1 is temporarily stored in a transmission buffer 13 during the changeover operation 14a 14c 14b of the switch 14 to be outputted to a modulator 12 along with the changeover to the 14b. Therefore, the transmission information is transmitted without intermission ion even after the line changeover on the transmission side. |
