X.control; Parameterization Of The Positioner; Safe Position - Definition Of The Safe Position - Burkert 8791 Manuel D'utilisation

Type 8791
Functions

10.2.5 X.CONTROL -

parameterization of the positioner
Use this function to set the parameters for the positioner (dead band and amplification factors (kp)).
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
Figure 20: X.CONTROL graph
Open/close amplification factor: Parameters for the positioner
Open amplification factor:
Close amplification factor:
10.2.6 SAFE POSITION -
Definition of the safe position
This function specifies the actuator safety position which is approached at defined signals.
The set safety position is only approached if there is a corresponding signal at the binary input (for con-
figuration see BINARY INPUT) or if a signal error occurs (for configuration see SIGNAL ERROR).
If the mechanical stroke range is limited with the X.LIMIT function, only safety positions within these limits
can be approached.
This function is executed in AUTOMATIC mode only.
Control
difference
Xd1
Position
actual value
Amplification factor of the positioner (for closing the valve)
Amplification factor of the positioner (for opening the valve)
Xd1'
Xd1
Dead band
english
to the
controller
Xd1'
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