HEIDENHAIN TNC 410 - Manual (Page 121)

7 Programming: Miscellaneous Functions 108
Entering contour transitions between contour
elements: M112
Standard behavior
The TNC stops briefly for all changes in direction that are greater
than the limit angle defined in MP7460(exact stop).
In program blocks with radius compensation (RR/RL), the TNC
automatically inserts a transition arc at outside corners.
Behavior with M112
You can adjust the effect of M112 by redefining machine
parameters.
M112 is effective in operation with servo lag as well as
operation with feedforward control.
The TNC inserts a selectable contour transition between any
contour elements (compensated and uncompensated), in the
plane or in three dimensions :
■ Tangential circle: MP7415.0 = 0
an acceleration jump results from the change in the curvature at
the connection points.
■ Third-degree polynomial (cubic spline): MP7415.0 = 1
There is no velocity jump at the connection points.
■ Fifth-degree polynomial: MP7415.0 = 2
There is no acceleration jump at the connection points.
■ Seventh-degree polynomial: MP7415.0 = 3 (standard setting)
There is no jump in the rate of acceleration change.
Permissible contour deviation T
With the tolerance value T you define the distance by which the
milled contour can deviate from the programmed contour. If you do
not enter a tolerance value, the TNC calculates the most exact
contour transition possible at the programmed feed rate.
Tolerance angle A
If you enter a tolerance angle A, the TNC smoothens only those
contour transitions whose angle of directional change is greater
than the programmed tolerance angle. If you enter a limit angle = 0,
the TNC moves the tool at a constant acceleration also over tangen-
tial transitions. Input range: 0° to 90°
X
Y
T
A
R
7.
4 Miscellaneous F
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or Cont
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