| 摘要 |
<p>PROBLEM TO BE SOLVED: To specify which of a modem and a telephone line is in trouble in the case of a line fault by a simple means without using any level meter. SOLUTION: The remote monitor and control system is constituted by connecting a remote monitor and control unit 1 installed in the center and a remote monitor and control unit 2 installed in a field through modems 3 and 4, a control line 5, and a display line 6 and trouble characteristic units 7 and 8 which disconnects the modems 3 and 4 of the remote monitor and control units 1 and 2 from the control line 5 and display line 6 in case of a line fault and send back and receive modem signals sent from the remote monitor and control units 1 and 2 are interposed between the modems 3 and 4 and the control line 5 and display line 6.</p> |
