Badger Meter SRD/SRI Valve Positioners - Manual (Page 48)

Decreasing Gain
Since there might be differences in control valve dynamic behavior when the Positioner output is increasing vs . decreasing,
two different sets are used . Each set has Proportional (proportional gain, unit-less), Integral (reset time, sec) and Derivative
(derivative time, sec) . These fields are automatically populated if Autostart is used .
Most of the time, Proportional and Integral action (PI controller) may yield acceptable control behavior . In certain cases (for
instance, integrating processes), Integral gain may also cause poor stability in the form of limit cycling and thus should be
limited . Too much derivative action may yield stability problems, therefore it should be handled carefully .
Decreasing Integral
Since there might be differences in control valve dynamic behavior when the Positioner output is increasing vs . decreasing,
two different sets are used . Each set has Proportional (proportional gain, unit-less), Integral (reset time, sec) and Derivative
(derivative time, sec) . These fields are automatically populated if Autostart is used .
Most of the time, Proportional and Integral action (PI controller) may yield acceptable control behavior . In certain cases (for
instance, integrating processes), Integral gain may also cause poor stability in the form of limit cycling and thus should be
limited . Too much derivative action may yield stability problems, therefore it should be handled carefully .
Decreasing Derivative
Since there might be differences in control valve dynamic behavior when the Positioner output is increasing vs . decreasing,
two different sets are used . Each set has Proportional (proportional gain, unit-less), Integral (reset time, sec) and Derivative
(derivative time, sec) . These fields are automatically populated if Autostart is used .
Most of the time, Proportional and Integral action (PI controller) may yield acceptable control behavior . In certain cases (for
instance, integrating processes), Integral gain may also cause poor stability in the form of limit cycling and thus should be
limited . Too much derivative action may yield stability problems, therefore it should be handled carefully .
Increasing Gain
Since there might be differences in control valve dynamic behavior when the Positioner output is increasing vs . decreasing,
two different sets are used . Each set has Proportional (proportional gain, unit-less), Integral (reset time, sec) and Derivative
(derivative time, sec) . These fields are automatically populated if Autostart is used .
Most of the time, Proportional and Integral action (PI controller) may yield acceptable control behavior . In certain cases (for
instance, integrating processes), Integral gain may also cause poor stability in the form of limit cycling and thus should be
limited . Too much derivative action may yield stability problems, therefore it should be handled carefully .
Increasing Integral
Since there might be differences in control valve dynamic behavior when the Positioner output is increasing vs . decreasing,
two different sets are used . Each set has Proportional (proportional gain, unit-less), Integral (reset time, sec) and Derivative
(derivative time, sec) . These fields are automatically populated if Autostart is used .
Most of the time, Proportional and Integral action (PI controller) may yield acceptable control behavior . In certain cases (for
instance, integrating processes), Integral gain may also cause poor stability in the form of limit cycling and thus should be
limited . Too much derivative action may yield stability problems, therefore it should be handled carefully .
Increasing Derivative
Since there might be differences in control valve dynamic behavior when the Positioner output is increasing vs . decreasing,
two different sets are used . Each set has Proportional (proportional gain, unit-less), Integral (reset time, sec) and Derivative
(derivative time, sec) . These fields are automatically populated if Autostart is used .
Most of the time, Proportional and Integral action (PI controller) may yield acceptable control behavior . In certain cases (for
instance, integrating processes), Integral gain may also cause poor stability in the form of limit cycling and thus should be
limited . Too much derivative action may yield stability problems, therefore it should be handled carefully .
Increasing Ramping
To modify the control valve dynamics, Travel Time Limits may be changed . Inputting values higher than the default (0 .4 sec)
will slow down the response .
Configuration / Parameter
Page 48 August 2014 POS-UM-00011-EN-02