HEIDENHAIN TNC 320 User Manual page 316

Please note while programming:
Danger of collision!
To prevent a collision between touch probe and
workpiece, enter a low estimate for the slot width.
If the slot width and the safety clearance do not permit
pre-positioning in the proximity of the touch points, the
TNC always starts probing from the center of the slot. In
this case the touch probe does not return to the clearance
height between the two measuring points.
Before a cycle definition you must have programmed a
tool call to define the touch probe axis.
Cycle parameters
U Center in 1st axis Q321 (absolute): Center of the slot
in the reference axis of the working plane. Input range
-99999.9999 to 99999.9999
U Center in 2nd axis Q322 (absolute): Center of the slot
in the minor axis of the working plane. Input range
-99999.9999 to 99999.9999
U
Width of slot Q311 (incremental): Width of the slot,
regardless of its position in the working plane. Input
range 0 to 99999.9999
U Measuring axis (1=1st axis / 2=2nd axis) Q272: Axis
in which the measurement is to be made:
1: Reference axis = measuring axis
2: Minor axis = measuring axis
U
Measuring height in the touch probe axis Q261
(absolute): Coordinate of the ball tip center (= touch
point) in the touch probe axis in which the
measurement is to be made. Input range
-99999.9999 to 99999.9999
U Set-up clearance Q320 (incremental): Additional
distance between measuring point and ball tip. Q320
is added to SET_UP (touch probe table). Input range
0 to 99999.9999
U Clearance height Q260 (absolute): Coordinate in the
touch probe axis at which no collision between touch
probe and workpiece (fixtures) can occur. Input range
-99999.9999 to 99999.9999
316 Touch Probe Cycles: Automatic Datum Setting