Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 347)

Chapter 13
Coordinate Control
13-5
Usually, workpieces on CNC lathes are cylindrical. The control allows
workpiece dimensions programming as either radius or diameter values.
G08 places the control in diameter programming mode. This mode
remains active until cancelled by a G07.
G07 places the control in radius programming mode. This mode remains
active until cancelled by a G08.
Either G08 or G07 can be selected by your system installer in AMP to be
the active mode at power-up. The currently active G-code can be
displayed by selecting the status screen. See section 8.1.
If program execution branches to a subprogram that changes to radius or
diameter mode, the control always reverts to the mode of the calling
program when subprogram execution is completed.
Example 13.3
Diameter/Radius Programming
Assume X is the diameter axis
Diameter Programming Mode (G08) Radius Programming Mode (G07)
Incremental Incremental
G90G00X0Z35;
G91G01F.1X12;
Z-10
G02Z-4X8I4;
G01Z-15; G90G00X0Z35;
G91G01F.1X6;
Z-10
G02Z-4X4I4;
G01Z-15;
Absolute Absolute
G90G00X0Z35;
G01F.1X12;
Z25;
G02Z21X20I4;
G01Z6; G90G00X0Z35;
G01F.1X6;
Z25;
G02Z21X10I4;
G01Z6;
13.4
Radius/Diameter Modes
(G07, G08)