| 摘要 |
PURPOSE:To obtain a controlling device for controlling a system to be controlled in the safe direction even if one system out of the remaining two systems in a triple constitution becomes defective by inputting a bias controlling the system to be controlled in the safe direction to an intermediate value selector instead of the defective system. CONSTITUTION:Commands of three commond generators 1, 2, 10 are inputted to the intermediate value selector (MVG)12 to select and output the intermediate value of the three commands. If the fault of one controlling system (command A for instance) is detected, a relay A-2 is actuated, said system is separated from the MVG and the operation of relays B-2, C-2 are inhibited. When the safe direction of the controlling system is turned to the closed direction, a closed bias 13 is inputted to the MVG instead of the separated system. Since a low value priority (LVG) is applied to the selection of the remaining two systems, the system to be controlled is controlled always in the safe direction even if one system becomes defective. |
