HEIDENHAIN ITNC 530 - 6-2010 DIN-ISO PROGRAMMING User Manual page 191

Direction of rotation DR for circular movements
When a circular path has no tangential transition to another contour
element, enter the direction of rotation as follows:
Clockwise direction of rotation: G02/G12
Counterclockwise direction of rotation: G03/G13
Radius compensation
The radius compensation must be in the block in which you move to
the first contour element. You cannot activate radius compensation in
a circle block. Activate it beforehand in a straight-line block (see "Path
Contours—Cartesian Coordinates", page 196).
Pre-positioning
Before running a part program, always pre-position the tool to prevent
the possibility of damaging it or the workpiece.
HEIDENHAIN iTNC 530 191