Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 342)

Coordinate Control
Chapter 11
11-26
In Figure 11.15, the center of rotation programmed in the G68 block is
ignored when the block immediately following the G68 is an incremental
motion block.
Angles and centers of rotation for G68 blocks are modal and remain in
effect for following G68 blocks until a new center of rotation or angle is
specified with a G68 command.
Important: You can rotate all of the work coordinate systems at once by
using the external part rotation, see page 11-28.
If rotating the coordinate system again in the same plane using another
G68 command, the angle of rotation is taken from the current rotated
coordinate position, not the original position (see Figure 11.16).
Rotating the coordinate system again in a different plane using another
G68 is allowed. The resulting work coordinate system is rotated in both
planes.
Executing a G69 cancels all G68 rotations and returns the coordinate
system back to its original orientation. Local rotation of a work coordinate
system using the G68 command is also canceled when the control executes
an M30 or M02 code in a program.