West Control Solutions Pro-4 - Manual (Page 18)

3.5.4 Step attempt after start-up
Condition: - tunE = 0 and sufficient set-point reserve provided
or - tunE = 2
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 pro-
cess 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 parame-
ters.
3.5.5 Pulse attempt after start-up
Condition: - tunE = 1 and sufficient set-point reserve provided.
The controller outputs 0% correcting variable or Y.Lo and waits, until the process
is at rest (see start conditions page 8)
Subsequently, a short pulse of 100% is output (Y=100%) and reset.
The controller attempts to determine the optimum control parameters from the
process response. If this is completed successfully, these 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 and line-out to the set-point, correcting
variable "heating" remains unchanged and a cooling pulse (100% cooling energy)
is output additionally. After successful determination of the “cooling parame-
ters”, the optimized parameters are used for line-out to the set-point.
3.5.6 Optimization at the set-point
Conditions:
w A sufficient set-point reserve is not provided at self-tuning start (see page 17).
w tunE is 0 or 1
w With Strt = 1 configured and detection of a process value oscillation by
more than ± 0,5% of (rnG.H - rnG.L) by the controller, the control
parameters are preset for process stabilization and the controller realizes an
optimization at the set-point (see figure “Optimization at the set-point”).
w when the step attempt after power-on has failed
w with active gradient function ( PArA/ SETP/ r.SP≠ OFF), the set-point
gradient is started from the process value and there isn't a sufficient set-point
reserve.
Operation
Self-tuning 18 KS 90-1 / KS 92-1