Omron E5CK User Manual page 38

J Auto-tuning
(A.T.)
F 40%AT
Deviation at start of AT
execution ≧ 10% full-scale
Set point
Start of AT
execution
The following diagram summarizes manual operation.
Manipulated variable (%)
0
Manipulated variable
switched
Manual
A/M
Auto
• AT (auto-tuning) cannot be executed while operation is canceled or dur-
ing ON/OFF control.
• When you execute auto-tuning, the optimum PID parameters are auto-
matically set by forcibly changing the manipulated variable to calculate
the characteristics (called the "limit cycle method") of the control target.
During auto-tuning, the AT LED flashes.
• 40%AT or 100%AT can be selected by the limit cycle of MV change width.
Specify [
rameter (level 1 mode).
• During heating and cooling control, only 100%AT can be executed. (So,
[ ] (40%AT) will not be displayed.)
• To cancel AT execution, specify [
In order to set the limit cycle of MV change width to 40%, select 40%AT
to execute auto-tuning with fluctuations in the process value kept to a
minimum. However, note that auto-tuning takes longer to execute
compared with 100%AT.
The timing by which limit cycles are generated varies according to wheth-
er or not the deviation (DV) at the start of AT execution is 10% full-scale
or less.
Limit cycle of MV change
width 40%
Deviation 10%
full-scale
End of AT
Balance-less, bump-less points
OFF ON
Power inter-
ruption
] or [ ], respectively, in the "AT execute/cancel" pa-
Deviation at start of AT
execution < 10% full-scale
Set point
Time
Start of AT
execution
3.7 Adjusting Control Operation
] ("AT cancel").
Limit cycle of MV change
width 40%
Deviation 10%
full-scale
Time
End of AT
Time
3--13