Burkert 8693 - Page 69

68
Type 8692, 8693
english
Start-up, operation
position controller Type 8692
Position set-point value [%]
CMD
Standardised valve stroke [%] (POS) In the case of control tasks for closed-loop control systems
it is usually particular demands which are placed on the
course of the operating characteristic, e.g. linearity. For this
reason it is occasionally necessary to correct the course
of the operating characteristic in a suitable way. For this
purpose the positioner features a transfer element which
implements different characteristics. These are used to
correct the operating characteristic.
Equal percentage characteristics 1:25, 1:33, 1:50, 25:1,
33:1 and 50:1 and a linear characteristic can be set. Fur-
thermore, a characteristic can be freely programmed via
nodes or automatically calibrated.
Inputting the freely programmable characteristic
The characteristic is defined via 21 nodes which are distributed uniformly via the position set-point values ranging from 0 – 100 %.
Their distance is 5 %. A freely selectable stroke (adjustment range 0 – 100 %) is assigned to each node. The difference between
the stroke values of two adjacent nodes must not be larger than 20 %.
FREE
y 0 ->: 0.0%
y 5 ->: 5.0%
y 100 ->: 100%
EXIT
SELEC
INPUT
+
-
y 0 ->: 0.0%
OK
INPUT
+
-
y 5 ->: 5.0%
OK
INPUT
+
-
y 100 ->: 100%
OK
*
*
*
Fig. 12: Operating structure CHARACT FREE
* If the sub-menu is left by pressing the selection key on the left (ESC), the value remains unchanged.