| 摘要 |
<p>PURPOSE:To measure the line loss efficiently by providing a device outputting automatically a measuring signal so as to measure it if an abnormality takes place in the communication state. CONSTITUTION:If a monitor object device causes a fault, a fault contact S1 is closed from the opened state, an installation device monitor T12 output a fault signal to a communication control section T11, from which a notice is given to a central monitor C. A communication control section C1 receiving the notice analyzes a reception signal and if an abnormality exists in the signal and a fault contact S1 operating signal cannot be recognized, a measured signal generating command is given to a measuring signal generation command section C3 to measure C4 the signal. Then the command section C3 gives a command of outputting a measured signal to a measuring signal generating section T13 of a terminal equipment T1 via a telephone line 1 and a prescribed measured signal is outputted to the line 1 from a generating section T13. On the other hand, the signal measuring section C4 of the device C measures the measuring signal level to check the line loss of the line 1. Thus, the line loss is checked automatically when the abnormality takes place.</p> |
