| 摘要 |
PURPOSE:To improve the reliability and operability of a remote folded test, by transmitting no test data when a line test is executed on a data transmitting system so that the establishment of a folded loop at the controlled side can be confirmed. CONSTITUTION:In case where a folded loop is formed at the controlled side by means of a loop commanding signal sent from the controlling side, a folding command signal LS is sent and, upon receiving this command signal, a folded loop is established at a controlled side MODEM2', when the testing switch 7 is turned on at a controlling side MODEM2. Simultaneously, the same operation as that made when a switch for folding test is turned on is performed at the controlled side MODEM2', by using a level signal LR which establishes the loop, and the folding command signal LS is returned to the MODEM2. The folding command signal LS returned from the controlled side MODEM2' at this time is detected at the controlling side and displayed on a display circuit 13. |
