HEIDENHAIN ITNC 530 User Manual page 337

Before programming, note the following:
Program a positioning block for the starting point (hole
center) in the working plane with radius compensation R0.
The algebraic sign of the cycle parameters depth of thread,
countersinking depth or sinking depth at front determines
the working direction. The working direction is defined in
the following sequence:
1. Depth of thread
2. Total hole depth
3. Depth at front
If you program a depth parameter to be 0, the TNC does
not execute that step.
Program the thread depth as a value smaller than the total
hole depth by at least one-third the thread pitch.
Enter in MP7441 bit 2 whether the TNC should output an
error message (bit 2=1) or not (bit 2=0) if a positive depth
is entered.
Danger of collision!
Keep in mind that the TNC reverses the calculation for pre-
positioning when a positive depth is entered. This
means that the tool moves at rapid traverse in the tool axis
at safety clearance below the workpiece surface!
HEIDENHAIN iTNC 530 337