ABB C1900 Series User Manual

20
Self-tune High Limit
Self-tune Low Limit
Hysteresis
Band
Hysteresis
Value
Output Step
Values at
Start of
Execution
Controller
Output
Time
Signal Noise
Set Point
PV
Output
Time
Output Step
Size
Time
Calculated Trip
Point
…5 CONTROL OPERATION
5.7 Auto-tuning Introduction
Information.
• On demand user-activated tuning.
• Two types of auto-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 can be selected.
• Automatic entry of calculated control terms – unless an auto-tune error occurs.
• Error and Caution messages – indicate reason for tuning problems.
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.
Information. 'At Set Point' auto-tuning automatically
calculates the PID terms based on the process reaction
during an auto-tuning cycle. The controller output is
manipulated to give six process oscillations which are
used to determine the tuning parameters.
Fig. 5.6 ‘Start-up’ Auto-tuning
Fig. 5.7 ‘At Set Point’ Auto-tuning

ABB C1900 Series Specifications

General

Brand	ABB
Model	C1900 Series
Category	Measuring Instruments
Language	English