| 摘要 |
PURPOSE:To facilitate operation for starting up process control by automatically varying the limit value of a limiter unit from a value equivalent to the normal-state value of an oerating terminal to a value equivalent to a miximum operation value according to prescribed transition characteristics. CONSTITUTION:When a control output signal to be integrated and held in a limiter unit 2 from a regulating unit 1 varies toward a miximum operation value according to a variation in limit value, an input signal nears a set value accordingly, so that when the limit value reaches some value, the input signal coincides with the set value. At this time, a control signal by the speed type arithmetic of the regulating unit 1 is ceased, so the control output signal to be integrated and held in the limiter unit 2 becomes equal to the limit value. Then, although the limit value further varies toward the miximum operation value, the control output signal never varies because the input signal coincides with the set value. Therefore, the control output signal is not limited later and an output signal based upon the arithmetic of the unit 1 is supplied to an operating terminal 4 to place a process in automatic mode. |
