HEIDENHAIN ITNC 530 User Manual page 207

Radius compensation
The tool radius compensation is programmed together with the first
contour point P in the APPR block. The DEP blocks automatically
A
discard the tool radius compensation.
Contour approach without radius compensation: If you program the
APPR block with R0, the TNC will calculate the tool path for a tool
radius of 0 mm and a radius compensation RR! The radius
compensation is necessary to set the direction of contour approach
and departure in the APPR/DEP LN and APPR/DEP CT functions. In
addition, you must program both coordinates in the working plane in
the first traverse block after APPR.
HEIDENHAIN iTNC 530 207