Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 212)

Servo Parameters
Chapter 7
7-66
Range
4 to 4,194,304
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 forces
your system into E--Stop, causing an error message to be displayed.
Notes
This parameter must be set independently for each servo.
Important: If your velocity loop is closed through the resolver of a 1326
motor connected through a 1394 drive or you are configuring a 9/440
resolver based system, you must set this parameter to either 32768 or 8192
counts. Refer to your Integration and Maintenance Manual for details. For
systems with high--resolution feedback, set your HIPERFACE absolute
device to 1,048,576 counts/cycle. If you have a HIPERFACE incremental
device, set it to 2,097,152 counts/cycle. Resolution of this feedback is
controlled by a dip switch on the 1394 system module with a CNC
interface. 9/440 resolver--based systems make this setting through
software (no dip switch is necessary).
Function
Important: The standard servo feedback configuration uses one feedback
device for both positioning and velocity data. If this is the case on your
system, this parameter must be set to the same value as the parameter Sign
of Position Feedback. Refer to this chapter’s overview for an example of
a system that uses two feedback devices for the same axis and may require
a different value be selected here.
This parameter allows the installer to reverse the polarity of the velocity
feedback without rewiring the encoder (usually this is the same sign as
selected with the parameter Sign of Position Feedback as it is typically
the same encoder).
If a separate feedback device (other than the encoder used for positioning
data) is used to derive velocity data, the sign of this parameter may be
different from the Sign of Position Feedback. When the encoder,
tachometer, or other feedback device is installed, the velocity feedback
may count up when it should count down. This is all relative to the desired
motor rotation direction as affected by gearing and encoder wiring.
7.3.4
Sign of Velocity Feedback