| 摘要 |
PURPOSE:To limit the observation of an international telephone line only to the quality of international telephone lines, by connecting a voltage level detector of a signal to a continuity test sound transmitter-reseiver on a common signal line and a line signal device on telephone lines. CONSTITUTION:The 1st level detector LVDET1 is connected to a line signal device SIG on telephone lines other than the signal line for common lines, and whether or not the reception level and the transmission level of the line signal are within the maintenace limit value is detected at the LVDET1. The result is inform to a central processing unit CC for an exchange as an observation information of call. The 2nd level detector LVDET2 is connected to a continuity test sound tramsmitter-receiver CTRS on the line for common line signal to detect whether or not the reception and transmission line of the continuity test sound is within the maintenance limit value, and the result is informed to the device CC as the observation information. |
