Rev. 1.0
WALTHER Temperature Controller Bundle WTRB-x-x
Page 40 of 42
Walther Systemtechnik GmbH
– D 76726 Germersheim
Telefon: +49 (0)7274-7022-0 Telefax: +49 (0)7274-7022-91
http://www.walther-2000.de
8.2 Self-Optimization
Self-optimization is performed according to the oscillatory method and will determine the optimum parameters
for a PID or PI controller.
Depending on the configured controller type (two-point, three-point, steady controller) and the controller struc-
ture (parameterization), the following parameters will be optimized:
Proportional range (Pb1, Pb2), derivative time (dt), reset time (rt), cycle time (Cy1, Cy2), filter time constant (dF;
parameter of the analog inlet).
Depending on the extent of the control deviation, the controller will select from two procedures for self-optimiza-
tion:
Self-optimization in start phase
Self-optimization for desired value
W des. value
S switching
level
T time
of
start
Conditions
The following conditions have to be met in order to start the self-optimization:
•
Start of the self-optimization is not locked by the binary function (binF)
•
Controller operates in automatic mode, not in manual mode
•
No active lock of parameter level through setup program
•
Keys (B) and (C) will not be operated separately. Make sure you press them synchronously.
In addition, the following steps should be taken into account or checked or actually taken before the actual start
of the self-optimization:
•
Has the matching controller type been configured?
•
Check or respectively adjust the control direction of the controller
•
Can the actual value be influenced in manual mode?
•
Only for steady controllers: The function of the output (OutP -> OutA) has to be configured as controller
outlet 1 and must be scaled to 0 ... 100 %. This means: Function (FnCt) = controller output 1 (9) zero
point (0Pnt) = 0 end value (End) = 100
Depending on the type of controller and the parameter settings, the controller structure and certain parameters
will be optimized:
Controller type
Parameter setting
Optimized
controller
structure
Optimized parameters
Two-point controller
rt > 0; dt = 0; Pb1 =
random
PI
Pb1, rt, Cy1, dF
all other settings
PID
Pb1, dt, rt, Cy1, dF
T
X
W
t
S
T
X
t
S
W
