WEST 8800 - 3.5 Self-tuning

3.5 Self-tuning
For determination of optimum process parameters, self-tuning is possible.
After starting by the operator, the controller makes an adaptation attempt,
whereby the process characteristics are used to calculate the parameters for fast
line-out to the set-point without overshoot.
The following parameters are optimized when self-tuning:
Parameter set 1:
Pb1 - Proportional band 1 (heating) in engineering units [e.g. °C]
ti1 - Integral time 1 (heating) in [s]
r only, unless set to OFF
td1 - Derivative time 1 (heating) in [s]
r only, unless set to OFF
t1 - Minimum cycle time 1 (heating) in [s]
r only, unless Adt0 was set to “no self-tuning” during
configuration by means of 8800/8840 configurator
®
.
Pb2 - Proportional band 2 (cooling) in engineering units [e.g. °C]
ti2 - Integral time 2 (cooling) in [s]
r only, unless set to OFF
td2 - Derivative time 2 (cooling) in [s]
r only, unless set to OFF
t2 - Minimum cycle time 2 (cooling) in [s]
r only, unless Adt0 was set to “no self-tuning” during
configuration by means of 8800/8840 configurator
®
.
Parameter set 2: analogous to parameter set 1 (see page25)
3.5.1 Preparation for self-tuning
w
Adjust the controller measuring range as control range limits. Set values
rnG.L and rnG.H to the limits of subsequent control.
(ConfigurationrControllerrlower and upper control range limits)
ConF r Cntr r rnG.L and rnG.H
w
Determine which parameter set shall be optimized.
-The instantaneously effective parameter set is optimized.
r Activate the relevant parameter set (1 or 2).
w
Determine which parameter set shall be optimized (see tables above).
w
Select the self-tuning method
see chapter 3.5.3
-Step attempt after start-up
-Pulse attempt after start-up
-Optimization at the set-point
Operation
Self-tuning 16 8800 process controller