Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 557)

Cutter Diameter Compensation
(G40, G41, G42)
Chapter 21
21-39
Figure 21.35
Change in Compensation with No Possible Tool Path Intersections
Compensated path G41
Programmed path G41
G42
G42
Programmed path
Compensated path G42
Compensated path G41
Programmed path
r
1
r
2 r
1
r
1
r
1
r
2
r
r
G41
The control is always looking ahead to the next motion block to determine
the actual tool path taken for a motion block in cutter compensation. If the
next block is not a motion block, the control continues to scan ahead for a
motion block until it either detects one or the allowable number of
non-motion blocks, as set in AMP, has been exceeded. Refer to
documentation prepared by the system installer for the allowable number
of non-motion blocks allowed in a specific system.
Important: The definition of a non-motion block is any block within a
program that does not actually generate the movement of one of the axes in
the current compensated plane. Blocks that are skipped by the control
because of the block-delete feature (/) discussed in section 7.1.1 are also
counted as a non-motion block in cutter compensation regardless of the
content of the skipped block.
21.6.2
Too Many Non-Motion
Blocks