Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 321)

Coordinate System Offsets
Chapter 11
11-5
The machine coordinate system is established by the control immediately
after the machine home operation is completed. The default work
coordinate system, determined in AMP by the system installer, is activated
simultaneously. The default work coordinate system is established upon
execution of a control reset operation, E-STOP, G92.1, or power up. The
default work coordinate system is the sum of the external offset value (if
any), and the offsets of the default coordinate system selected in AMP
(G54-G59.3 or none). If the default coordinate system is selected as none,
the default work coordinate system will be simply the external offset (if
any). This manual assumes G54 to be the default coordinate system and no
external offset has been centered.
Figure 11.4
Work Coordinate System Definition
G54 Work coordinate system
X
X
Machine coordinate system
Machine home
-2
-3
2
3
Y Y
In the above figure the machine coordinate system was defined by
declaring the fixed position machine home as the point X=-3., Y=-2. Then
the G54 work coordinate system zero point is defined by the coordinates
X=3., Y=2. in the machine coordinate system.
Coordinate positions in a part program are manipulated as coordinate
values in the G54 default work coordinate system unless another
coordinate system is selected by programming G54-G59.3.