HEIDENHAIN TNC 640, User Manual, Page: 385 / 948

Programming Q Parameters | Calculation of circles
10
HEIDENHAIN | TNC 640 | Conversational Programming User's Manual | 10/2017
385
10.5 Calculation of circles
Application
The control 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, for example, 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 control 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 control 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.