
13. Program Support Functions
13.18 Spline; G05.1
437
When the above conditions are satisfied, the spline curve will be revised so that the error
between P3-P4 in Fig. 2 is within the designated value.
P0
P1
P2
P3
P4
P5
P6
P7
Spline curve
Tolerance (chord error)
Inflection point
Fine segment
Fig. 1 Spline curve before error revision
P4
P3
Spline curve after revision
Spline curve before revision
Chord error designated in the
parameter "Toler-1"
Fig. 2 Spline curve after error revision
In parameter "Toler-1", set the tolerance for developing into fine segments with the CAM.
Set a smaller value if the expansion (indentation) is apparent due to the relation with the
adjacent cutting paths.
(b) Chord error of block not containing inflection point
Even in blocks that do not contain an inflection point, if the block lengths are not matched,
the tolerance of the spline curve may increase. The curve may also expand due to the
effect of relatively short blocks.
At sections where the tolerance (chord error) of the fine segment block and spline curve in
a block not containing an inflection point, if the chord error in the corresponding section is
larger than the value set in parameter (#8028 Toler-2), the spline curve shape is
automatically revised so that the error is within the designated value. However, if the
maximum chord error of the corresponding section is more than five times larger than the
parameter "Toler-2" setting value, the spline function will be temporarily canceled.
The curve is revised only in the corresponding block.
The revisions are carried out with the following conditions for each block in the spline
interpolation mode.
There is no inflection point in the spline curve, and the maximum error of the spline
curve and linear block is larger than parameter "Toler-2". (Distance between P2-P3
in Fig. 3)