| 摘要 |
PROBLEM TO BE SOLVED: To perform the test of normality of a subscriber line, without operating a terminal for 'no ringing' communication service or without ringing a subscriber terminal. SOLUTION: The two lines of subscriber lines are short-circuited by switches S2 and S4, and measuring voltage lower than the voltage, with which the terminal for no-ringing communication service operates, is applied to the short- circuited two lines from the voltage-dividing circuit by resistors R2 and R3. Then, the magnitude of external voltage is measured with a computing unit 5. COPYRIGHT: (C)2004,JPO
|
