GE FVP110 - Servo_Deadband; Servo_Rate; Servo_Rate_Gain; Servo Deadband

FVP 110 Fieldbus Valve Positioner Manual
260
GE Energy
SERVO_RATE
Tuning range: 0, 0.05 to 1.0 sec (Default: 0.22 sec)
Set the derivative time of PI-D control.
The derivative term relates to the feedback and prevents a rapid output change, and the
preventive effect increases in proportion to the derivative time.
If a rapid response causes an overshoot, set a larger value for the derivative time to
prevent a rapid change and reduce overshoot. However, if the effect of this change is
excessive, tracking capability during step response decreases. If 0 is set, this function is
invalid.
SERVO_RATE_GAIN
Tuning range: 2 to 20 (Default: 5)
Set the gain in the derivative term of PI-D control.
As with SERVO_RATE, this parameter relates to the derivative term of control, and the
preventive effect increases in proportion to an increase in the gain in the derivative term.
SERVO_DEADBAND
Tuning range: 0 to 50% (Default: 0%)
Setting this parameter stops an integral operation in the vicinity of the Set point.
Figure 89 Servo Deadband
If you set the parameter SERVO_DEADBAND when, for example, the friction of a valve is
large, a limit cycle can be prevented. However, the value of the steady-state deviation
could be as large as that of SERVO_DEADBAND.