Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 400)

Axis Motion
Chapter 14
14-24
Angles may be entered in a polar block with positive or negative values.
Angles are referenced counter-clockwise if specified as positive and
clockwise if negative. Clockwise and counterclockwise orientation for the
X, Y, and Z axes is shown in Figure 14.3.
Angle values greater than 360 degrees are permitted. Programming 365
degrees or 725 degrees will have the same result as if 5 degrees were
programmed.
Radius values may be programmed as positive or negative values. When
specifying a radius value as a negative amount it is referenced in a
direction 180 degrees from the currently specified angle.
The axis position displays will not show the polar coordinate values during
polar programming. These displays will always show the current cartesian
coordinate position as described in section 8.1
Important: Polar programming mode has no effect on axis words that are
programmed with any of the following G--codes. Any axis words in any of
these blocks are executed as if polar programming was not active. Axis
words specified in these blocks have no effect on the current angle or
radius active in polar programming.
Coordinate system offset G52
Coordinate system offset G92
Work coordinate system rotation G68
Dwell G04
G10 blocks that modify tables
Programmable zone blocks G22
Programmable mirror image G50.1
Motion in the machine coordinate system G53
Though polar programming has no effect on programming these G--codes,
many of these G--codes have a significant impact on the execution of polar
programming.
For example a G68 work coordinate system rotation will have a major
impact on angles specified in a polar programming block. When the
coordinate system is rotated the polar angle is referenced from the rotated
axis. Work coordinate system offsets will have a similar effect on the work
coordinate system zero point thus moving the location of the radius vector
start point.
Axis words that are programmed with any of the return to/from home
G--codes (G27 - G30) to specify an intermediate point, are interpreted as
polar coordinate values when in polar programming mode.