Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 399)

Axis Motion
Chapter 14
14-23
If programming in absolute mode (G90):
The radius is measured from the zero point of the currently active work
coordinate system at the specified angle and defines a vector. This
vector is independent of the current tool position.
The angle is referenced from the first axis that is used to define the
currently active plane and is independent of the previous move.
Example 14.8
Incremental Versus Absolute Polar Blocks
Incremental Absolute
N10 G00 X0 Y0 F150; N10 G00 X0 Y0 F150;
N20 G91 G01 X10 Y10; N20 G90;
N30 G16; N30 G01 X10 Y10;
N40 X22 Y10; N40 G16;
N50 X15 Y260; N50 X22 Y10;
N60 G15; N60 X15 Y80;
N70 M30; N70 G15;
N80 M30;
Figure 14.12
Results of Incremental Versus Absolute Polar Programming Example
Incremental polar
positioning
Absolute polar
positioning
10
•
relative to first axis
defining current plane (previous
move was not polar)
25
20
15
10
5
25
20
15
10
5
30 25 20 15 10 5
20 15 10 5
N20
N40
N50
X X
Y
Y
N50
N20
N40
10
•
80
•
260
•
from
previous
polar move