| 摘要 |
In a comparing circuit, the value of a control signal from a higher-level device and a normal range that is set for the control signal are compared, and the result is sent to a control unit. The control unit, when sent the result indicating that the value of the control signal is outside of the normal range, forcibly adjusts the electric current signal (the adjusted electric current) to the electropneumatic converter to zero, regardless of the deviation between the value indicated by the control signal and the value indicated by the valve opening signal. The adjustment of the electric current in the control unit is performed using a normal function that is possessed by the control unit, that is, the function for changing continuously the value of the electric current signal in accordance with the deviation. |
