摘要 |
PURPOSE:To get rid of a malfunction, by making a decision as to an operation of a switch. CONSTITUTION:Switch position signals P1, P2... from an operation switch 1 are inputted to an operation block 3. Position signals for inhibiting the operation are also inputted to the operation block 3. If the operation switch 1 is operated to the position which has been inhibited, a gate circuit in the operation block 3 inhibits an outputs of a signal corresponding to the switch. Accordingly, a state of an output signal of the operation block 3 is maintained as before. In the event of an error, even if the switch is operated to the position which has been inhibited, in a flurry, a malfunction of a plant is not caused. |