Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 413)

Spindles
Chapter 17
17-15
Only the primary spindle (selected with G12.1) can be used in coordination
with virtual C. On systems allowing auxiliary spindles, if the auxiliary
spindle is the controlling spindle when virtual C is activated, this error
message appears, “ILLEGAL CODE DURING VIRTUAL C.”
Cylindrical interpolation coordinates the motion of the virtual C axis with
that of the linear machine axes to machine contours on the side of a
cylindrical workpiece as shown in Figure 17.3. Virtual C cylindrical
interpolation mode is turned on using a G16.1 block and turned off with a
G15 block (or a G16.2 block requesting end face milling). A G15 block
can not contain any axis words.
Figure 17.3
Virtual C Axis Cylindrical Interpolation
X
Z
C
Lathe Live Tool
The following are not allowed during cylindrical interpolation:
automatic motion to and from home G27, G28, G29, or G30
work coordinate changes and shifts G53, G54-G59, G59.1, G59.2,
G59.3, G50/G92, G52, G92.1
all turning and threading cycles
all drilling, tapping, and boring cycles
Cylindrical Interpolation Block Format
The format for the G16.1 block (virtual C axis cylindrical interpolation) is:
G16.1 R__ F__; C__ Z__;
17.5.1
Virtual C Axis,
Cylindrical Interpolation