Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 229)

Servo Parameters
Chapter 7
7-83
Function
Feed to hard stop is only available on mill control types.
Use this parameter to have the servo for an axis that has reached a hard
stop maintain a holding torque to keep constant pressure against the hard
stop. If all motor torque was removed from an axis that has reached a hard
stop some bounce could occur allowing the axis to move away from the
mechanical stop. Also once a motor reaches the hard stop it would be
impossible for the servo to respond quick enough, without a holding
torque, to prevent any instantaneous forces from momentarily forcing the
axis away from the hard stop.
This parameter specifies the torque that the servo generates to maintain
force against a hard stop once it has been reached. Enter this torque value
as a percentage of the servo’s maximum rated torque.
Axis Number Axis Number
(1) [1150] (7) [7150]
(2) [2150] (8) [8150]
(3) [3150] (9) [9150]
(4) [4150] (10) [4150]
(5) [5150] (11) [5150]
(6) [6150] (12) [6150]
Range
1 to 100% of motor rated current (continuous duty)
Notes
In order to perform feed to hard stop you must set the Servo Loop Type
parameter as either position/velocity or digital.
This parameter must be set independently for each axis that uses the feed to
hard stop feature.
7.3.16
Hard Stop Holding Torque