| 摘要 |
PURPOSE:To prevent a malfunction due to the disturbance of the data of an optical fiber cable by supervising the lowering of the supply voltage of data transmission equipment to be connected, and separating the data transmission equipment from which a power source is disconnected before error generation by means of the logic part of the data transmission euqipment. CONSTITUTION:To respective pieces of data transmission euqipment loop- connected by an optical fiber cable 11, comparators 18 to detect that the voltage of a power source 14 is lowered to less than a prescribed value are provided, and a relay 16 to turn off the power source 14 inputted to an optical switch 12 when the comparator 18 detects the lowering of the source 14 voltage is provided. In such a manner, when the power source 14 is turned off and the lowering of the source 14 voltage is generated, the comparator 18 detects the lowering of source voltage, operates a relay, and separates the data transmission equipment 13 from the optical fiber cable 11. Thus, the data disorder due to the malfunction of the data transmission equipment 13 can be prevented. |
