Omron E5AK PROGRAMMABLE TYPE User Manual page 61

J Auto-tuning
(A.T.)
F 40%AT
Deviation at start of AT
execution ≧ 10% FS
Set point
Start of AT
execution
F 100%AT
• AT (auto-tuning) cannot be executed while operation is reset or dur-
ing ON/OFF control.
• When you execute auto-tuning, the optimum PID parameters are au-
tomatically set by forcibly changing the manipulated variable to cal-
culate the characteristics (called the "limit cycle method") of the con-
trol target. During auto-tuning, time counting is stopped and the
"AT" LED flashes.
• 40%AT or 100%AT can be selected by the limit cycle of MV change
width. Specify [
cancel" parameter (level 1 mode).
• During heating and cooling control on a standard type controller, and
on a position-proportional type controller, only 100%AT can be
executed. (So, "
• 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
Time
End of AT
execution
In order to set the limit cycle of MV change width to 100%, select
100%AT to shorten the AT execution time without worrying about fluc-
tuations in the process value.
Set point
Start of AT
execution
3.8 Adjusting Control Operation
] or [ ], respectively, in the "AT execute/
: 40%AT" is not displayed.)
: AT cancel".
Deviation at start of AT
execution < 10% full-scale
Set point
Deviation 10%
full-scale
Start of AT
execution
Limit cycle of MV
change width 100%
End of AT
execution
Limit cycle of MV change
width 40%
Time
End of AT
execution
Time
3--25