Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 542)

Dresser/Wheel Radius Compensation
Chapter 15
15-54
Regardless of how you activate the new offset, radius compensation can
compensate for this new diameter by modifying the saved jogged path.
This path is modified so that the new dresser/wheel cuts the same part as
the old dresser/wheel. The absolute position of the machine is therefore
different on the return path from what it was when jogging away from the
part.
The control adjusts this jogged path when you press the
button to return from the jog retract. Once you press the
button, the control generates a move that offsets the current position by the
necessary distance. This distance is determined as being the necessary
distance the dresser/wheel would have to be positioned at so that the exact
same jog return paths can be used to return to the part and yet have the
end-point be offset from the original position by the difference in the
dresser/wheel radius.
ATTENTION: Make sure that this offset path does not cause
any collisions with the part or the machine fixtures. The
position of the dresser/wheel when the change in jog retract is
made should be a safe distance from the part and machine
fixtures.