Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 317)

Chapter
11
11-1
Coordinate Systems Offsets
This chapter covers the control of the coordinate systems. G-words in this
chapter will be among the first programmed because they define the
coordinate systems of the machine in which axis motion is programmed in.
This chapter describes:
Information about: On page:
Machine (absolute) coordinate system 11-1
Preset work coordinate systems; G54 - G59.3 11-4
External offsets 11-9
Offsetting the work coordinate systems 11-13
PAL Offsets 11-22
The control has two types of coordinate systems. One is the work
coordinate system, which is based on the coordinate system in the part
drawing for a part to be cut by the machine. The other is the machine
coordinate system (often referred to as the Absolute Coordinator System),
which is unique to the individual machine tool. Programs are usually
written in the work coordinate system.
The machine coordinate system is the basic coordinate system set for every
machine. It is established after completion of the machine homing
operation. It can not be offset or shifted in any way. Its position is
determined in AMP by the system installer.
Important: Before any coordinate system can be activated, the machine
must be homed. The homing operation refers to the positioning of the axes
to a machine-dependent fixed position, which is called the machine home.
For more on machine homing refer to section 4.3.
The zero point of the machine coordinate system is referenced from the
machine home point. This is done by assigning a coordinate location to
the machine home point. Though frequently defined as X0Y0Z0, the home
position for each axis can be given any legal coordinates such as 15.00,
-20.0000, or -2.256.
Once established, the machine coordinate system is not affected by a
control reset operation or any other programming or operator operation.
11.0
Chapter Overview
11.1
Machine Coordinate System
(Absolute)