Endress+Hauser TopClean S CPC 30, Руководство по эксплуатации

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6 Commissioning TopClean S CPC 30
56 EHauser
Fig. 25: Diagram to describe the most important corner points for control
With this characteristic curve, a set actuating variable is prescribed to the controller for
each pH value.
Neutral zone:
If the actual value (X) is within the neutral zone, then
•
the dosing does not take place for the Batch process type,
•
also not for the Inline process type and without an I component (Tn=0).
•
If the controller is configured as a PI or PID controller for the Inline type, the controller
decides itself if dosing will be carried out or not. This is dependent on the pH value
history.
Points of the characteristic curve:
For
constant control gain
("linear characteristic curve"), you require:
Set point W,
Neutral zone
– Two-sided: "Start of the neutral zone" and "End of neutral zone"
– One-sided: only one of the two points
For
range-dependent modulation gain
("segmented characteristic curve"), you require
two-sided control of all the points.
A point usually consists of two coordinates: an x coordinate (here = pH-value) and a y
coordinate (here = actuating variable). You only need enter the y coordinates for the
optimisation points. For the other points, the CPM 153 sets the y coordinates itself.
However, you cannot change the sequence of these defined points. It is, for example,
not possible to enter a larger pH value for the
"Start neutral zone
" than for the set point.
100 %
-100 %
0 %
Kp(X)
X
SetPoint BaseNeutral AcidTentative AcidFull AcidNeutral BaseTentative BaseFull
C07-CPM153xx-05-06-00-en-007.EPS
X too big
⇒
dosing
acid
X too low
⇒
dosing
base