West Control Solutions KS98-1 - Manual (Page 244)

After successful self-tuning, the controller goes to the automatic mode and controls the using the new parameters.
Parameter
Ores indicates the self-tuning result (r see page 246) .
a
When finishing self-tuning with an error ( Ada_Err), the stable correcting variable is output, until
self-tuning is finished by the operator via system menu, front-panel key
H , or via interface.
Start from manual mode
To start self-tuning from manual mode, switch the controller to manual. During transition to manual mode, the correc -
ting variable output last is taken over as manual correcting variable. At self-tuning start, this correcting variable is ta -
ken over and output as temporary stable correcting variable. Like in automatic mode, the can be changed at any time.
With ‘Process at rest’ (PiR) detection and a sufficient reserve (r see page 243), the correcting variable is changed by
the correcting variable step
dYOpt (increased with indirect controller, decreased with direct controller). `Process at
Rest’ (PiR) can be reached at starting time, i.e. the normal 60 s waiting time can be avoided.
The self-tuning procedure is realized using the varying process value.
After successful self-tuning, the controller goes to the automatic mode and controls the using the new parameters.
Parameter
Ores indicates the self-tuning results (r see page 246) .
a
When finishing self-tuning with an error ( Ada_Err), the stable correcting variable is output, until
self-tuning is finished by the operator via system menu, front-panel key
H , or via interface.
Self-tuning procedure with heating:
(2-point, 3-point stepping, continuous controller)
After reaching ‘Process in rest’, the process is stimulated by means of an output step change and the process response
is used to determine Tu1 and Vmax1 at the step response reversal point, if possible.
Controller 9499-040-82711
III-244 Self-tuning
r controller adaptation to the process
t
t
Y
100%
0%
X, W
W
X
60s
PiR
Start H
I
+
+
+
Start
Adaption
Optimisation
finished
> 10% W0/W100
dYopt
Off/Ok PIR_H Step Off/Ok
Fig.: 64 Start by rising the setpoint
t
t
Y
100%
0%
X, W
W
X
60s
PiR
Start H
D
+ +
Start
Adaption
Optimisation
finished
dYopt
Off/Ok PIR_H Step Off/Ok
Fig.: 65 Start by lowering the setpoint