Rockwell Automation 1398-DDM-xxx USE MNL/ULTRA 200 DIG.SERVO.DR - Manual (Page 178)

Publication 1398-5.0 – October 1998
9-8 Tuning
Manual Tuning
Manual tuning may be used to adjust the gain control parameters P, I,
D and the filters. A square wave is generated by the drive to assist in
the adjustment. Manual velocity tuning requires the following:
●
Step Period value to be specified
●
Step Velocity value to be specified.
Tuning the Velocity Loop
The Auto Tune procedure provides a starting point for velocity loop
tuning. Manual tuning is desirable when very precise adjustments are
required.
The following steps describe how to manually tune the velocity loop.
These steps precede the manual position loop tuning procedure, which
should follow velocity loop tuning.
1. Disable the drive.
2. Choose Manual T une (Velocity Step) from the Tuning window.
3. Enter the desired step Velo c ity (rpm) of the internal square wave
generator.
4. Enter the desired T ime to complete one cycle of the square wave
of the internal step velocity.
5. Select the desired Motor Direction ( For w ard Only , Re v erse
Only , or B i-Directional ).
6. Select the Osc i lloscope .
7. Enable the drive.
8. Choose S tart . The motor should start moving and the oscilloscope
will display the commanded velocity and the motor velocity.
9. While monitoring the motor velocity waveform, increase P-gain
until the desired rise time is achieved.
10. While monitoring the motor velocity waveform, increase I-gain
until an acceptable amount of overshoot is reached.
11. Apply filtering by selecting F ilters , and then select Filter E nable .
12. While monitoring the motor velocity waveform, decrease the fil-
ter B andwidth until the overshoot begins to increase (in many
applications the filter is not necessary).
13. Choose S top .
Note: Always tune the velocity loop before the position loop, as Veloc-
ity loop tuning affects the position loop response.