| 摘要 |
PURPOSE:To avoid malfunction through the reception of light after the end of cut- off signal, by holding the cut-off state for a prescribed time in cutting off the power supply unit, by using a special cut-off signal and discriminating it at a logic section of a terminal device. CONSTITUTION:Each terminal device is provided with a logic section (g) discriminating the cut-off signal of power supply, a special cut-off signal is outputted to an optical fiber cable (c) from a main body (a), and when the cut-off signal is inputted to the logic section (g) via an optical relay device (d), it is discriminated at the logic section (g) and the cut-off signal is transmitted to the switch means of power supply unit (e). On the hand, in the power supply unit (e), after the power supply is disconnected with the cut off signal, the re-closing of the power supply is inhibited even if the closing signal is incoming for a prescribed time. |
