| 摘要 |
PURPOSE:To separate easily a fault area and to attain an automatic test of a channel system of a time division switch for a time division electronic exchange device, by testing a channel part which returns at a digital section with a digital signal transmission/reception trunk. CONSTITUTION:When a test is given first to a subscriber system, a selection circuit 105 performs selection as shown by broken lines in a figure with a command of a control part 104. Thus the circuit 105 is connected to a digital signal transmission/reception trunk 103 via a time division switch 107. The digital signal delivered from the trunk 103 is returned by the circuit 105 via a channel 1 of the switch 107 and sent back via a channel 2. The trunl 103 compares the returned reception digital signal with delivered digital signal and secures the automatic decision whether or not the channel part has a fault. An automatic test is also possible in the same way with a digital circuit system. |
