66
Operation and function
14.2.5
X.CONTROL
-
Control parameters 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. stroke limit maximum - stroke limit minimum (see auxiliary function stroke limit (
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 control parameters (
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. 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‘
Figure 40:
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)
14.2.6
SAFPOS
-
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 a error occurs.
If the mechanical stroke range is limited with the stroke limit function (
X.LIMIT)
, only safety posi-
tions within these limits can be approached.
This function is executed in AUTOMATIC operating state only.
english
Type 8696, REV.2
Summary of Contents for 8696
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