HEIDENHAIN TNC 640 (34059x-05) - Manual (Page 306)

Programming: Q Parameters
9.5 Calculation of circles
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TNC 640 | User's Manual
HEIDENHAIN Conversational Programming | 1/2015
9.5 Calculation of circles
Application
The TNC can use the functions for calculating circles to calculate
the circle center and the circle radius from three or four given
points on the circle. The calculation is more accurate if four points
are used.
Application: These functions can be used if you wish to determine
the location and size of a hole or a pitch circle using the
programmable probing function.
Soft key Function
FN 23: Determining the CIRCLE DATA from
three points
e. g.
FN 23: Q20 = CDATA Q30
The coordinate pairs of three points on a circle must be saved in
Q30 and the following five parameters—in this case, up to Q35.
The TNC then saves the circle center in the reference axis (X if
spindle axis is Z) in parameter Q20, the circle center in the minor
axis (Y if spindle axis is Z) in parameter Q21, and the circle radius in
parameter Q22.
Soft key Function
FN 24: Determining the CIRCLE DATA from
four points
e. g.
FN 24: Q20 = CDATA Q30
The coordinate pairs of four points on a circle must be saved in Q30
and the following seven parameters—in this case, up to Q37.
The TNC then saves the circle center in the reference axis (X if
spindle axis is Z) in parameter Q20, the circle center in the minor
axis (Y if spindle axis is Z) in parameter Q21, and the circle radius in
parameter Q22.
Note that
FN 23 and FN 24 automatically overwrite
the resulting parameter and the two following
parameters.