HEIDENHAIN TNC 320 User Manual page 382

16.6 MEAS. CIRCLE OUTSIDE
(Cycle 422, DIN/ISO: G422)
Cycle run
Touch Probe Cycle 422 measures the center and diameter of a circular
stud. If you define the corresponding tolerance values in the cycle, the
TNC makes a nominal-to-actual value comparison and saves the
deviation value in system parameters.
1 The TNC positions the touch probe at rapid traverse (value from
FMAX column) following the positioning logic (see "Executing
touch probe cycles" on page 285) to the starting point 1. The TNC
calculates the touch points from the data in the cycle and the
safety clearance from the SET_UP column of the touch probe
table.
2 Then the touch probe moves to the entered measuring height and
probes the first touch point at the probing feed rate (column F). The
TNC derives the probing direction automatically from the
programmed starting angle.
3 Then the touch probe moves in a circular arc either at measuring
height or at clearance height to the next starting point
the second touch point.
4 The TNC positions the probe to starting point
point 4 to probe the third and fourth touch points.
5 Finally the TNC returns the touch probe to the clearance height and
saves the actual values and the deviations in the following
Q parameters:
Parameter number Meaning
Q151 Actual value of center in reference axis
Q152 Actual value of center in minor axis
Q153 Actual value of diameter
Q161 Deviation at center of reference axis
Q162 Deviation at center of minor axis
Q163 Deviation from diameter
Please note while programming:
Before a cycle definition you must have programmed a
tool call to define the touch probe axis.
The smaller the angle, the less accurately the TNC can
calculate the dimensions of the stud. Minimum input
value: 5°
382
2 and probes
3 and then to starting
Touch Probe Cycles: Automatic Workpiece Inspection