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For Auto Tune ( Limit Cycle Tuning ) operation
:
1-
Tune slection parameter in “run List” menu must be selected
Auto
tune
or
Auto-Self tune
.
2 -
For being started Tune operation (Auto Tune or Self Tune) control form must be P,
PI, PD or PID.
3 -
If process set value is changed while Tune operation is being performed, Tune
operation is canceled.
i
3-
After changing set value, if difference between newly defined set value and
former set value is greater than proportional band, device will start it.
If set value is changed to a value that is greater than;
± [ Scale * ( Heating or Cooling Proportional Band) ] /1000 value,
Parameter is adjusted by the device and
Auto Tune
operation is
started.
Example -1 : Starting Auto Tune operation by the user ;
!
Enter technician menu.
!
Adjust tune selection parameter in ”run List” menu ,
Auto Tune
Or
Auto-Self Tune
!
Adjust automatic tune selection parameter in ”run List” menu
And return to main operation screen.
!
Observe that “AT” led is active.
Canceling
Auto Tune
operation
Auto Tune is canceled. Then, without doing any changes in PID parameters and
Parameter, device continues to run with former PID parameters.
:
1-
If sensor breaks ;
2-
If
Auto Tune
operation can not be completed in 8 hours
3-
If user adjusts
parameter or
4-
If user adjusts
parameter
5-
If process set value is changed while Tune operation is being performed
6-
While Tune operation is being performed, if operation type selection is changed
as “Manual” when it is “Automatic” (If operation type selection is changed as
“Automatic” when it is “Manual”, then Tune operation is started again)
7-
If output function is changed while Tune operation is being performed
(Heat
Þ
Cool, Cool
Þ
Heat)
8-
While Tune operation is being performed, if control form is changed as “ON/OFF”
when it is “PID” (If control form is changed as “PID” when it is “ON/OFF”, the Tune
operation is started again)
If
Auto Tune
operation finishes without any problem, device saves the PID
coefficients to memory and continue to run. Parameter is adjusted
automatically.
There are 2 different methods for determining PID parameters by the device. These
are
Auto tune
( Limit Cycle Tuning) and
Self Tune
(Step Response Tuning)
methods.
TUNE METHODS
Determining of PID parameters with
Auto Tune
is started in these conditions :
1-
By the user in any time,
2-
By the device when system gets unstable and starts oscillation
If process value is out of
Set ± Process value stabilisation
value (Please
refer to Section 6.2.4) and starts to oscillates, then device changes the
Parameter to and Auto Tune operation is started.
