West Control Solutions KS 42-1 - Manual (Page 15)

Start condition:
w Rest condition
For process evaluation, a stable condition is required. Therefore, the controller
waits until the process has reached a stable condition after self-tuning start.
The rest condition is considered being reached, when the process value oscillati-
on is smaller than
± 0,5% of (rnG.H - rnG.L).
Set-point reserve
After having come to rest with 0% correcting variable or with
Y.Lo, the
controller requires a sufficient set-point reserve for its self-tuning attempt, in
order to avoid overshoot.
Sufficient set-point reserve:
inverse controller:(with process value
SP.Hi - SP.LO)
direct controller:(with process value>set-point+ (10% of SP.Hi - SP.LO)
3.5.3 Self-tuning start
g
Self-tuning start can be locked via BlueControl
(engineering tool) (
P.Loc).
The operator can start self-tuning at any time.
For this, keys Ù and È must be pressed simul-
taneously. The AdA LED starts blinking. The
controller outputs 0% or
Y.Lo, waits until the
process is at rest and starts self-tuning (AdA
LED lit permanently).
After successful self-tuning, the AdA-LED is off and the controller continues
operating with the new control parameters.
3.5.4 Self-tuning cancellation
By the operator:
Self-tuning can always be cancelled by the operator. For this, press Ù and È
key simultaneously. With manual-automatic switch-over configured via Ò key,
self-tuning can also be canceled by actuating Ò key. The controller continues
operating with the old parameters in automatic mode in the first case and in ma-
nual mode in the second case.
By the controller:
If the Err LED starts blinking whilst self-tuning is running, successful self-tuning
is prevented due to the control conditions. In this case, self-tuning was cancelled
by the controller.
Dependent of control type, the output status is:
w 3-pnt. stepping controller:
actuator is closed (0% output)
w 2-pnt./ 3-pnt./ continuous controller:
If self-tuning was started from the automatic mode, the controller output is
0%. With self-tuning started from manual mode, the controller output is Y2.
Operation
Operating KS4x-1 15 Self-tuning
125
126
SP.x run
Ada
Err