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Conditions where self-tuning cannot be used
Self-tuning cannot be used in the following situations:
During control standby
•
During ON/OFF (2-position) control
•
During auto-tuning
•
•
During ramp soak progress
When there is error input
•
•
When set for dual output
When any of the P, I, D, Ar parameters are set to manual
•
•
During manual mode
During soft start progress
•
Conditions to halt self-tuning
Halt self-tuning in the following situations:
When there is a change in SV (This includes the case where SV changes because of the
•
ramp soak function, remote SV function, or ramp SV.)
When self-tuning has not finished after running for nine or more hours
•
Setting self-tuning
Turn on power of the controller and set the SV.
1
Display the system menu ("
S S S S Y Y Y Y S S S S [ [ [ [ h h h h 7 7 7 7
2
Display the controller parameter ("
3
Press the
key to set the value.
4
Turn off power of the controller.
5
Turn on power of the control target equipment and the controller. Turn on
6
power of the control equipment first.
Self-tuning will begin.
process value
SV
tuning
dead time
lag time
The equipment will not tune correctly if power of the controller is
•
Point
turned on first.
•
To reset self-tuning, set the control method to PID ("
before changing back to self-tuning.
7-5
PID2 Control
In case which the power supply of the control target goes ON → OFF → ON, this PID2 control
can suppress the amount of overshoot.
This control introduces an algorithm to prevent the calculated PID result from becoming a mis-
calculation, even when the control loop is open.
You will need to run auto-tuning to set the PID parameter when using PID2 control.
●
Features of PID2 Control
process value
control equipment power
control loop
Setting PID2 control
S S S S Y Y Y Y S S S S C C C C h h h h 7 7 7 7
Display the system menu ("
1
Display the control parameter ("
2
Press the
key to set the value.
3
7-6
Auto-tuning
Run auto-tuning to set the PID parameter automatically.
A A A A t t t t
"
" set value
Behavior
Function
"
o o o o F F F F F F F F
"
Stop/Finish
Stops or finishes auto-tuning.
"
o o o o n n n n
"
Normal type
The standard auto-tuning for SV reference. Choose this
auto-tuning in most situations.
L L L L o o o o
"
"
Low PV type
Auto-tuning for SV-10% reference. Choose this when you
want to suppress the overshoot when tuning.
").
[ [ [ [ t t t t r r r r L L L L
") and choose self-tuning ("
t
suppress overshoot
SV
PV
t
ON
OFF
close
close
open
").
C C C C T T T T r r r r L L L L
") and choose PID2 ("
P P P P i i i i d d d d 2 2 2 2
").
●
Normal type
process value AT start
SV
Point
Running auto-tuning
Display the operation menu ("
1
Display auto-tuning ("
2
Choose the standard type ("
Press the
3
A decimal point will blink at the bottom of the display during auto-tuning.
When auto-tuning has successfully competed, blinking decimal point will turn off and
overwrites the PID.
S S S S E E E E L L L L F F F F
").
Point
P P P P i i i i D D D D
") once
7-7
Valve controls adjust and control the valve position according to [OPEN] and [CLOSE] of the
contact signal.
Turn on the contact outputs in manual mode, so that pressing the
pressing the
Note: Srv2 or PFb cannot be used in PXG4.
Setting Servo Control 1
Display the system menu ("
1
Display the control parameter ("
2
This chooses "Servo Control 1".
Press the
3
Point
Caution
Setting the valve stroke time
The valve stroke time must be set to use valve control.
Display the PFB menu ("
1
Display the valve stroke time parameter ("
2
valve in use.
Press the
3
– 11 –
●
Low PV type
process value AT start
AT calculating
PID control
PV
t
Set the following parameters before running auto-tuning.
•
PV input type / PV input upper limit / PV input lower limit / Decimal
position / PV input filter in the setup channel menu ("
•
OUT1 proportion cycle (OUT2 proportion cycle) in the PID channel
menu ("
P P P P i i i i d d d d C C C C h h h h 2 2 2 2
").
o o o o P P P P E E E E [ [ [ [ h h h h 1 1 1 1
").
A A A A t t t t
") and choose the tuning type.
o o o o n n n n
") or low PV type ("
key to start auto-tuning.
PID parameter which is set after auto tuning has finished normally
•
will be maintained even when the power is turned off. However, the
PID value will not be changed if the power is turned off during auto-
tuning. In this case, rerun auto-tuning.
The equipment will use ON/OFF (2 position) control during auto-
•
tuning, so there may be a large change in PV according to the pro-
cess. Do not use auto-tuning for processes that do not permit a
large change in PV. Do not use auto-tuning for processes such as
pressure control and flow control that have a fast response.
•
Auto-tuning is not behaving normally if it has not finished after four
or more hours have passed. In these cases, recheck parameters
such as input/output wiring, control output behavior (normal/
reverse), and input sensor type.
•
Rerun auto-tuning if there is a large change in SV, a change in the
PV input type, or a change in the control target conditions that
reduces the effectiveness of the controls.
You can run auto-tuning when the control type is set to "fuzzy" or
•
"PID2".
You cannot run auto-tuning in manual mode.
•
When using the PID selection function, the auto-tuning result for
•
the selected PID group is stored.
Auto tuning is forcibly terminated when SV changes because of the
•
ramp soak function, remote SV function, or ramp SV.
Valve Control (Servo Control 1)
key means "CLOSE"
OPEN contact output
CLOSE contact output
Valve motor
(servo 1)
Valve
S S S S Y Y Y Y S S S S C C C C h h h h 7 7 7 7
").
P P P P r r r r C C C C S S S S
") and choose servo control 1 ("
key to set the value.
An interlock function is not built in.
Chattering may occur if the dead band ("
is set too small.
P P P P F F F F B B B B [ [ [ [ h h h h 1 1 1 1 0 0 0 0
").
key to set the value.
AT calculating
SV-10%FS
SV
PV
PID control
t
S S S S E E E E T T T T C C C C h h h h 6 6 6 6
")
L L L L o o o o
") according to the control target.
key means "OPEN", and
set value input
(temperature)
boiler
S S S S r r r r v v v v 1 1 1 1
").
P P P P G G G G A A A A P P P P
P P P P F F F F B B B B C C C C h h h h 1 1 1 1 0 0 0 0
") in the PFB menu ("
t t t t r r r r v v v v L L L L
") and set the stroke time for the
")
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