| 摘要 |
<p>PURPOSE:To reduce a test time by selecting and displaying the loopback of a line loopback cable through one kind of loopback cable based on a transmission control procedure of a line system generation. CONSTITUTION:The combination of loopback is provided to a loopback selection circuit 2 in advance, and the loopback selection circuit 2 is selected by using the output signal of a decode circuit 6 to select the loopback in matching with the transmission control procedure or loopback method. Moreover, the signal reflected by the loopback selection circuit 2 is displayed for its state by a line signal display circuit 3. Furthermore, the output signal of the decode circuit 6 is supplied to a loopback display circuit 5 to display the loopback state. Since the loopback of the line loopback cable is selected and displayed by one kind of loopback cable based on the line system generation transmission control means in such a way, the test time is reduced.</p> |
