Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 203)

Servo Parameters
Chapter 7
7-57
Important: If configuring a linear position feedback device (excluding
distance--coded marker systems) use the parameters Position Feedback
Counts/Cycle and Lead Screw Thread Pitch to enter the number of
counts returned by the device per revolution of the lead screw. The ratio
between Teeth on Gear for Position FB and the parameter Teeth on
Lead Screw for Position Feedback should be one to one. For example if
the linear device has 5000 lines per 1/2 inch enter 5000 as the Position
Feedback Counts/Cycle and .5 inch as the Lead Screw Thread Pitch.
Both Teeth on Gear for Position Feedback and Teeth on Lead Screw
for Position Feedback can then be set to one.
In some cases there may be a series of gears or gearbelt pulleys that make
up a final gear ratio for a servo. In this case, it is necessary to factor this
gear ratio into this parameter and the parameter Teeth on Gear for
Pos FB.
Important: The system automatically reduces the gear ratio to the lowest
common denominator. For example, a ratio of 44:40 will be reduced to
11:10 on an AMP upload.
Refer to Figure 7.31 for an illustration of typical gearing for position
feedback devices.
Axis Parameter
Number
Axis Parameter
Number
(1) [1027] (7) [7027]
(2) [2027] (8) [8027]
(3) [3027] (9) [9027]
(4) [4027] (10) [10027]
(5) [5027] (11) [11027]
(6) [6027] (12) [12027]
Range
1 to 32767
Notes
When configuring any closed--loop axis you must configure two gear ratios
for feedback; one for velocity feedback, the other for position feedback.
On axes with a single feedback device, the setup and gear ratios should be
identical for position and velocity feedback since the same device is being
used for both feedback types.
This parameter must be set independently for each servo.