Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 544)

Dresser/Wheel Radius Compensation
Chapter 15
15-56
Figure 15.49 is an example of the possible path taken when interrupting
automatic operation during radius compensation to execute MDI motion
blocks. The same path would apply if interrupting radius compensation to
perform a manual jog move.
Figure 15.49
Dresser/Wheel Radius Compensation Interrupted with MDI Blocks
3 MDI blocks
(no compensation
applied)
End-point
of MDI
r
r
Compensation
re-initializes
here
G42
Programmed path
12140-I
Important: If during cutter compensation, you switch out of automatic
mode and either:
generate axis motion in manual mode on an axis in the compensation
plane, or
execute any block in MDI mode,
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 dresser/wheel radius.
Figure 15.50 illustrates these conditions.