Continuous adaptive tune is
particularly suitable for con-
trolling process whose control
characteristics change with
time or are not linear in rela-
tion to the Setpoint values.
It doesn’t require any operation
by the user. It is simple and
works fine: it samples continu-
ously the process response to
the various perturbations, deter-
mining the frequency and the
46
4 - Operation
Natural frequency is selected
when the PV is close to the SP
Setpoint.
This method has the advantage
of a better accuracy in the term
calculation with a reasonable
speed calculation.
The Fuzzy Tuning determines
automatically the best method
to use to calculate the PID
term, according the process
conditions.
Natural frequency
PV variable
Control output
tuning start
End of the tuning
operating and setting
of the new calculated
terms.
Perturbation
New
parameters
Continuous adaptive tune
4.5.4 TUNING MENU (Cont.)
The self-learning adaptive auto-
tune is not intrusive. It doesn’t
affect the process, at all, during
the phase of calculation of the
optimal terms parameters.
Fuzzy-Tuning is selected when,
at the start of the autotune oper-
ation, the PV is far from the
Setpoint of more than 5% of the
span. This method has the big
advantage of fast calculation,
with a reasonable accuracy in
the term calculation.
amplitude of the signals. On the
basis of this data and their sta-
tistical values, stored in the
instrument, it modifies auto-
matically the PID term parame-
ters.
It is the ideal for all applications
where it is required to change
continuously the PID terms para-
meters, in order to adjust the PID
to the changes of the process
dynamic conditions.
In case of power off with the
Adaptive Tune enabled, the
values of the PID terms para-
meters are stored, in order to
be reused at the next power
on.
At power on the Adaptive Tune
starts automatically.
x5-uk-ed5 17-09-2009 14:53 Pagina 46
To Next Page
Loading...
Need help?
General
