| 摘要 |
PURPOSE:To realize line fall back preventing intermission of data transfer by switching the line speed and continuing the data transfer on a low speed line when line quality deterioration is detected in a system executing data transfer. CONSTITUTION:A line monitor device 11 logs error information and check the line quality switching condition. If errors, 60 times per min take place, the line monitor device 11 transmits a switch command to a line speed switching device 21, transmits an SDS signal to an MODEM30 to switch the timing signal of the MODEM30 from high to low speed. Then the timing of the MODEM31 is switched and the data from a terminal device 40 to a central processing unit 10 is transferred as a low speed line. |
