West Control Solutions KS 42-1 - Manual (Page 14)

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, where-
by 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 BlueControl
®.
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 BlueControl
®
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. (Configuration
rControllerrlower and upper control range limits)
ConFrCntrr rnG.L and rnG.H
w Determine which parameter set shall be optimized (see tables above).
3.5.2 Self-tuning sequence
The controller outputs 0% correcting variable or Y.Lo and waits, until the process
is at rest (see start-conditions on page 8).
Subsequently, a correcting variable step change to 100% is output.
The controller attempts to calculate the optimum control parameters from the
process response. If this is done successfully, the optimized parameters are taken
over and used for line-out to the set-point.
With a 3-point controller, this is followed by “cooling”.
After completing the 1st step as described, a correcting variable of -100% (100%
cooling energy) is output from the set-point.
After successfull determination of the “cooling parameters”, line-out to the
set-point is using the optimized parameters.
Operation
Self-tuning 14 Operating KS4x-1