Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 320)

Coordinate System Offsets
Chapter 11
11-14
For example specifying values of zero for all axes in a G92 block causes
the current tool position to become the zero point of the current work
coordinate system.
Execution of a G92 block does not produce any axis motion.
Important: Any axis not specified in the G92 block is not offset, and the
current coordinate position for that axis remains unchanged.
Once the work coordinate system is offset, all absolute positioning
commands in the program are executed as coordinate values in the offset
coordinate system.
Example 11.5
Work Coordinate System Offset (G92)
Program Block Comment
G54 G00; G54 work coordinate system
X35. Z25.; rapid move to X35, Z25 in the G54 work
coordinate system
G92X10.Z10.; Redefines current axis position to have
the coordinates X10, Z10
The zero point of the offset G54 work coordinate system is 10 units away
from the current tool location in both the X and Z directions. If the Z
value had not been entered in the G92 block, the Z coordinate location
would have remained unchanged (Z25.)