HEIDENHAIN TNC 320 User Manual page 285

Executing touch probe cycles
All touch probe cycles are DEF active. This means that the TNC runs
the cycle automatically as soon as the TNC executes the cycle
definition in the program run.
Danger of collision!
When running touch probe cycles, Cycle 8 MIRROR
IMAGE, Cycle 11 SCALING and Cycle 26 AXIS-SPECIFIC
SCALING must not be active.
You can also run the Touch Probe Cycles 408 to 419 during
an active basic rotation. Make sure, however, that the
basic rotation angle does not change when you use Cycle
7 DATUM SHIFT with datum tables after the measuring
cycle.
Touch probe cycles with a number greater than 400 position the touch
probe according to a positioning logic:
If the current coordinate of the south pole of the stylus is less than
the coordinate of the clearance height (defined in the cycle), the TNC
retracts the touch probe in the probe axis to the clearance height
and then positions it in the working plane to the first starting
position.
If the current coordinate of the south pole of the stylus is greater
than the coordinate of the clearance height, the TNC first positions
the probe in the working plane to the first starting position and then
moves it immediately to the measuring height in the touch probe
axis.
HEIDENHAIN TNC 320 285