| 摘要 |
<p>PURPOSE:To facilitate a loop back test by providing a loop back means which compares a signal on which a direct current from a reception transmission path is superimposed with a transmitted signal, records the number of the coincident times of the signal superimposes the direct signal on the signal received in a loop back device and loops back it to the reception transmission path in a preceding stage in a tester, and first and second transfer means. CONSTITUTION:A data transmission means 101 which superimposes the direct current on the signal transmitted to a transmission path and transmits it and a comparison means 108 which compares the signal on which the direct current from the reception transmission path is superimposed with the transmitted signal and records the number of coincident times are provided. The loop back means 205 which superimposes the direct current on the received signal and loops back it to the reception transmission path in the preceding stage when the direct current from the transmission path in the preceding stage is detected, the first transfer means 209 which superimposes the direct current on the received signal when the direct current is detected in the signal from the transmission path in the preceding stage and which transmits it to a transmission path in a subsequent stage, and the second transfer means 202 and 204 transmitting the signal which is received from the reception transmission path in the subsequent stage and to which the direct current superimposed to the reception transmission path in the subsequent stage are given to the loop back device. Thus, a loop back test can be conducted without the need of setting a test code.</p> |
