| 摘要 |
PURPOSE:To reduce the line test time and to relieve the load of a maintenance personnel by using a command from plural time division line concentrators without intervention of a central controller to reflex automatically a communication line between the said concentrators and an exchange thereby attaining the test of plural communication lines at the same time from the plural line concentrators. CONSTITUTION:In testing a communication line ln between a line circuit LUn and an ELUn, an LU number LUn and test command are given to a test circuit TST from an operation display section CNS, then a transmission signal from a switch SW on a backward superhighway BSHW is suppressed by a command signal on a signal line TST1, and a test signal is transmitted succeedingly to a line reflection command signal from a test signal line TBD. The signal reaches the circuit ELUn via DMPX- LUn-ln-HW. When the circuit ELUn detects a reflected command signal by a reflection signal detecting circuit RTNDET, reflects the signal for a prescribed time to the selection circuit SEL and transmits to the reflected command signal to the transmission line HW. The reflected command signal is received by the circuit TST, the reception signal and the transmitted test signal are collated and the result of collation is displayed on an operation display section CNS. |
