HEIDENHAIN TNC 410 ISO Programming - Manual (Page 180)

154 7 Programming: Miscellaneous Functions
7.
4 M
isc
ellan
e
ou
s F
u
n
c
tio
n
s
f
o
r Cont
our
ing
Beha
vior
Insert rounding arc between straight lines: M112
(TNC 426, TNC 430)
Compatibility
For reasons of compatibility, the M112 function is still available on the
TNC 426 and T30 controls. However, to define the tolerance for fast
contour milling, HEIDENHAIN recommends the use of the
TOLERANCE cycle for these TNCs, see “TOLERANCE (Cycle G62, not
TNC 410),” page 313.
Entering contour transitions between contour
elements: M112 (TNC 410)
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 (G41/G42), the TNC
automatically inserts a transition arc at outside corners.
Behavior with M112
The TNC inserts a selectable contour transition between any contour
elements (compensated and uncompensated), in the plane or in three
dimensions:
n Tangential circle: MP7415.0 = 0
An acceleration jump results from the change in the curvature at the
connection points.
n Third-degree polynomial (cubic spline): MP7415.0 = 1
There is no velocity jump at the connection points.
n Fifth-degree polynomial: MP7415.0 = 2
There is no acceleration jump at the connection points.
n
Seventh-degree polynomial: MP7415.0 = 3 (standard setting)
There is no jump in the rate of acceleration change
Permissible contour deviation E
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.
Limit angle H
If you enter a limit angle A, the TNC smoothens only those contour
transitions whose angle of directional change is greater than the
programmed limit angle. If you enter a limit angle = 0, the TNC moves
the tool at a constant acceleration also over tangential transitions.
Input range: 0° to 90°.
X
Y
T
A
R
You can adjust the effect of M112 by redefining machine
parameters.