Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 199)

Servo Parameters
Chapter 7
7-53
Important: The 9/440HR incremental feedback device is capable of
achieving 2,097,152 cnts/mm (53,267,660.8 cnts/in.). Exceeding this
number of feedback counts for any feedback/axis pitch combination holds
your system in E--Stop, causing an error message to be displayed.
Notes
This parameter must be set independently for each servo.
Note higher resolution feedback devices can exceed the controls maximum
feedback frequency at higher speeds. Refer to your integration and
maintenance manual for more information.
Function
This parameter allows the installer to reverse the polarity of the feedback
without rewiring the encoder.
When the encoder is installed, feedback should count up as the axis is
moved in the positive direction, and count down when the axis is moved in
the negative direction. This is all relative to axis direction assignment,
rotation direction changes through gearing and encoder phasing.
After encoder installation, if it is determined that the 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.”
ATTENTION: Axis runaway can result if this parameter is
incorrect. Refer to the notes in this section for integration
suggestions.
Axis Parameter
Number
Axis Parameter
Number
(1) [1595] (9) [9595]
(2) [2595] (10) [10595]
(3) [3595] (11) [11595]
(4) [4595] (12) [12595]
(5) [5595] (13) [13595]
(6) [6595] (14) [14595]
(7) [7595] (15) [15595]
(8) [8595]
7.2.14
Sign of Position Feedback