Rockwell Automation 1398-DDM-xxx USE MNL/ULTRA 200 DIG.SERVO.DR - Manual (Page 171)

Publication 1398-5.0 – October 1998
Chapter 9
Tuning
Chapter 9
ULTRA 200 Series drives are tuned quickly and easily for a wide
variety of applications. Two tuning modes are available through the
software:
●
Auto Tune
●
Manual Tune
Tuning Guidelines
The following tuning guidelines briefly describe the tuning
adjustments. These guidelines provide you with a basic reference
point should the application require additional adjustments.
General Tuning Rules
1. Tune the velocity loop first and then, if the drive uses following or
step/direction commands, tune the position loop.
2. To widen the velocity loop bandwidth, increase the P-gain setting,
decrease the I-gain setting or increase the low-pass filter band-
width. This provides a faster rise time and increases drive
response.
3. To increase stiffness, increase the I-gain setting. It rejects load dis-
turbance and compensates for system friction.
4. To reduce velocity loop overshoot, increase P-gain or D-gain, or
decrease I-gain.
5. To reduce mechanical resonance, use a stiffer mechanical cou-
pling or select a nega-tive (-) D-gain value. Alternatively,
decrease the low-pass filter value and the velocity loop update
rate.
6. If the motor oscillates, decrease either individually or together
the:
• P-gain
• I-gain
• low-pass filter bandwidth.
High Inertia Loads
Proper compensation of load inertia may not be simply a matter of
increasing the P-gain and I-gain settings. Problems are often
encountered when tuning systems with a high load to motor inertia
ratio.