Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 742)

Integrating a Linear Feedback Device
Appendix B
B-4
To properly configure the velocity loop you must identify to the control the
type of feedback device expected, and the number of feedback counts that
should be expected per unit of axis travel. We strongly recommend you
use motor mounted feedback to close the velocity loop and do not attempt
to use a linear feedback device for this loop. Closing the velocity loop
with something other than motor mounted feedback can cause undesirable
results from any unmonitored backlash that may exist in the axis drive
gearing.
Velocity feedback is used relative to the rotation of the lead screw. Any
gearing or belts that exists between lead screw rotation and the velocity
feedback device must be entered as “Teeth on Lead Screw” and “Teeth on
Gear for Velocity Feedback”.
Important: If you choose to use the same linear feedback device to close
the velocity loop that you used to close the position loop (not
recommended as discussed above) the parameters for the velocity loop
must match the position loop parameters.
END OF APPENDIX
B.3
Configuring the Velocity
Loop with Linear Feedback