| 摘要 |
PURPOSE:To enable to know the condition of connecting lines, by controlling the impedance alteration circuit and measuring circuit of hybrid with the control and testing the lines to each subscriber line. CONSTITUTION:The impdance alteration circuit IMP of hybrid is provided at the line output of the two wire and four wire conversion circuit HXB, and the test signal generator OSC and the output measuring circuit M inverted with the two and four wire conversion circuit HXB are connected at the time sharing communication line TDSW, and the circuit IMP and the measuring circuit M are controlled with the control circuit CONT. Thus, the line test is made to each suscriber SUB line under non-operation. Moreover, the balance of hybrid is temporarily unbalanced, reflection is made with hybrid, and the reflected outpput is measured, allowing to know the condition of connecting line. |
