| 摘要 |
PURPOSE:To improve the safety and reliability of control, by interrupting a control circuit and a plurality of apparatuses on the basis of output from a decoder for detecting the combination of the output of a select signal generating means for generating control signals to a plurality of apparatuses. CONSTITUTION:Let it be supposed that a select switch 1d remains as it is closed due to troubles or errors when controlling an apparatus 2b. When operating a select switch 1b in order to select the apparatus 2b at that time, a relay 3d is under an operation condition because the select switch 1d also closes, and two apparatuses 2b, 2d are connected to a control bus 9. However, signals are not put out to every output becuase a condition that only either of select switches 1a-1d is selected is not detected at a decoder 6. Thus, signals are not put out from a gate 7, a contact 8-1 of a relay 8 remains as it is opened and the bus 9 is not connected to a controller 4. |
