47
AT
Autotuning:
Autotuning is the automatic calculation and
entering of the control parameters (P, I and D) into memo-
ry. Autotuning will also automatically set anti-reset wind-
up (Ar). There are two types of Autotuning that can be
performed by the controller, Autotuning at main setpoint
or Autotuning at 10% of full scale below main setpoint.
The latter may yield slightly different values, not as pre-
cise, but the process overshoot encountered during the
autotuning procedure would not be as much. Enter the
value for the type of autotuning you would like to run on
your particular application based on overshoot toler-
ances and the precision of the PID parameters needed.
For more information on principles of Autotuning, refer to
Appendix A. See also page 28.
Setting: 0 - Autotuning off
1 - Autotuning performed at setpoint
2 - Autotuning performed at 10% of full scale
below setpoint
Start of AT
End of AT
AT in operation
Set value (SV)
100%
0%
ON-OFF action
PV
ON
OFF
ON
OFF
(Measured value)
PID control
Start of AT
End of AT
AT in operation
Set value (SV)
100%
0%
ON-OFF action
PV
ON
OFF
ON
OFF
PID control
SV-10%FS
(Control output)
(Control output)
(Measured value)
Standard type (AT=1)
Low PV type (AT=2)
