HEIDENHAIN MANUALPLUS 620 User Manual page 420

For the cutting direction, machining direction and direction of tool
rotation, please refer to table G845 in the User's Manual.
For the machining direction Q=1 (from the outside toward
the inside), please note:
The contour must start with a linear element.
If the starting element is < WB, WB is reduced to the
length of the starting element.
The length of the starting element must not be less than
1.5 times the diameter of the milling cutter.
Cycle run
1 Starting position (X, Y, Z, C) is the position before the cycle
begins.
2 Calculates the number of cuts (infeeds to the milling planes,
infeeds in the milling depths) and the plunging positions and
paths for reciprocating or helical plunges.
3 Approaches to safety clearance and, depending on O, feeds to
the first milling depth or approaches helically or on a
reciprocating path, .
4 Mills a plane.
5 Retracts by the safety clearance, returns and cuts to the next
milling depth.
6 Repeat steps 4 and 5 until the complete surface is milled.
7 Returns to retraction plane RB.
420 DIN Programming for the Y Axis