HEIDENHAIN ITNC 530 - CYCLE PROGRAMMING User Manual page 250

Characteristics of the fixed cycles
The TNC automatically positions the tool to the setup clearance
before a cycle.
Each level of infeed depth is milled without interruptions since the
cutter traverses around islands instead of over them.
The radius of "inside corners" can be programmed—the tool keeps
moving to prevent surface blemishes at inside corners (this applies
for the outermost pass in the Rough-out and Side Finishing cycles).
The contour is approached on a tangential arc for side finishing.
For floor finishing, the tool again approaches the workpiece on a
tangential arc (for tool axis Z, for example, the arc may be in the Z/X
plane).
The contour is machined throughout in either climb or up-cut milling.
With Machine Parameter 7420 you can determine where
the tool is positioned at the end of Cycles 21 to 24.
The machining data (such as milling depth, finishing allowance and
setup clearance) are entered as CONTOUR DATA in Cycle 20.
250 Fixed Cycles: Contour Pocket with Contour Formula