Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 514)

Dresser/Wheel Radius Compensation
Chapter 15
15-26
If the vector defined by I and/or K is parallel to the programmed
dresser/wheel path, the resulting exit move is offset in the opposite
direction of the I and/or K vector by one radius of the dresser/wheel.
See Figure 15.21.
Figure 15.21
Exit Move When I, K Vector Is Parallel to Programmed Dresser/Wheel Path
Intercept line
Compensated path
Programmed path
I, K
r
r
r
Compensated path using I, K vector
Compensated path if no I, K in G40 block
12113-I
Important: If you do not program I and/or K, their value defaults to 0.