| 摘要 |
PURPOSE:To prevent an output to a controlled system in case the output of a control device is not normal, by providing an erroneous output preventing switch circuit between a control device and the controlled system and then turning on the switch circuit with an operation permitting output. CONSTITUTION:A control device 1 performs a control operation on the basis of the input of an input device, etc. and delivers an output through a control output signal line 2. Then the device 1 delivers a control output signal to a controlled system 3 when a switch circuit 4 is turned on. The control output signal to the controlled system 3 is held with the output obtained immediately before the circuit 4 is turned off if the circuit 4 is turned off. The ON/OFF of the circuit 4 is indicated by a signal obtained by converting a momentary output into a latch type output with a software. The controlled system 3 has no abnormal operation even though the ON/OFF command to the circuit 4 is equal to the latch output produced at a hardware latch contact. |
