Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 213)

Servo Parameters
Chapter 7
7-67
After installation of a separate velocity feedback device, it is determined
that this velocity feedback is counting up when it should be counting
down, or counting down when it should be counting up, it can be corrected
simply by changing this parameter to “Minus.” When the sign of this
parameter is incorrect the control may enter E--Stop when axis motion
takes place.
ATTENTION: Motor runaway can result if this parameter is
incorrect.
Axis Parameter
Number
Axis Parameter
Number
(1) [1600] (7) [7600]
(2) [2600] (8) [8600]
(3) [3600] (9) [9600]
(4) [4600] (10) [10600]
(5) [5600] (11) [11600]
(6) [6600] (12) [12600]
Range
Selection Result
(a) Plus
(b) Minus
Notes
This parameter must be set independently for each servo.
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.