Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 565)

Cutter Diameter Compensation
(G40, G41, G42)
Chapter 21
21-47
Figure 21.44 is an example of the possible tool path that is taken when you
interrupt an automatic operation during cutter compensation to execute
MDI motion blocks. This same tool path applies also, if you interrupt
cutter compensation to perform a manual jog move.
Figure 21.44
Cutter Compensation Interrupted with MDI Blocks
3 MDI blocks
(no compensation
applied)
End
point
of MDI
r
r
Compensation
re-initializes
here
G42
Programmed path
Important: If during cutter compensation, you switch out of automatic
mode and either:
generate axis motion in manual mode on an axis in the cutter
compensation plane, or
execute any block in MDI mode,
cutter compensation is re-initialize when you return to automatic mode.
This produces a path that is different from the path that would have been
produced had the manual or MDI operation not been done, even if you
returned the tool to the point of interrupt. In absolute mode the control
returns to the originally compensated path after it executes a block that
contains both axes in the compensation plane. In incremental mode, the
compensated path remains offset by the additional tool radius.
Figure 21.45 illustrates these conditions.