Endress+Hauser Topclean S CPC30, Руководство по эксплуатации

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6 Commissioning Topclean S
80 Hauser
For difficult neutralisations, the CPM153 controller gives you the option of partially compensating
for the non-linearity by entering an inverse characteristic Y(X).
C07-CPM153xx-05-06-00-en-007.eps
ƒig. 43: Diagram to describe the most important corner points for control
With this characteristic, a reference set value is given to the controller for each pH value.
Mycom S internally converts this characteristic into Kr(X) (modulation gain). The modulation gain
is only identical to the characteristic in case of a pure P controller. If a PI or PID controller is used,
the modulation gain deviates from the shown characteristic accordingly.
Neutral zone:
If the actual value (X) is within the neutral zone, dosing takes place as follows:
• Dosing does not take place for the Batch process type.
• Dosing does also not take place for the Inline process type without an I component (Tn=0).
• If the controller is configured as a PI or PID controller for the Inline type, it depends on the pH
value history if dosing takes place or not.
Points of the characteristic:
For constant control gain ("linear characteristic"), 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 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 = set value). You only need to enter the y coordinates for the optimisation points. For the other
points, the CPM153 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 of the neutral zone " than for the set point.