15
6
TUNING LEVEL
6.1
Introduction to Self-tuning
Information.
•
On demand user-activated tuning.
•
Two types of self-tuning – initial
'Start-up'
and when close to
'Set Point'
.
•
Tuning for P, PI or PID control can be selected.
•
Tuning for
1
/
4
wave damped or minimum overshoot (start-up tuning only) can be
selected.
•
Error and Caution messages – indicate reason for tuning problems.
•
Self-tune facility – not available on Heat/Cool Control and Boundless.
Fig. 6.1 'Start Up' Self-tuning
Information. The noise level of the process is monitored and then a step is applied to
the control output value. The response of the process is recorded and these results
are used to calculate the control terms.
Set Point
PV
Output
Time
Output Step
Size
Time
Calculated Trip
Point
