Burkert Type 8791 - Manual (Page 48)

48
ConfiguringAuxiliaryFunctions
8.5.5. X.CONTROL -
parameterization of the positioner
Use this function to set the parameters for the positioner (dead band and amplification factors (kp)).
1
1
1.0 % X.CONTROL deadband
kp open
kp close
Fig. 42: X.CONTROL menu item
Deadband: Insensitivity range of the positioner
Entry for the deadband as a % in reference to the scaled stroke range;
i.e. X.LIMIT upper stroke limit - X.LIMIT lower stroke (see auxiliary function
X.LIMIT).
This function causes the controller to respond only beginning at a specific control difference. This function saves
wear on the solenoid valves in the positioner and the pneumatic actuator.
If the auxiliary function X.CONTROL is in the main menu while X.TUNE (Autotune of the positioner) is
running, the deadband is determined automatically depending on the friction behavior of the actuator drive.
The value determined in this way is an approximate value. You can re-adjust it manually.
Position set-
point value Control
difference
Xd1
Position
actual value
to the
controller
Xd1‘
Dead band
Xd1
Xd1‘
Fig. 43: X.CONTROL graph
Open/close amplification factor: Parameters for the positioner
Open amplification factor: Amplification factor of the positioner (for closing the valve)
Close amplification factor: Amplification factor of the positioner (for opening the valve)
English
Software Tool - Positioner