Siemens SINUMERIK 840D sl Programming Manual page 594

Work preparation
3.7 Special motion commands
BSPLINE:
CSPLINE:
Points along a curve and check points:
X... Y... Z...
A... B... C...
Point weight (only B spline):
PW:
<n>:
Spline degree (only B spline):
SD:
Distance between nodes (only B spline):
PL :
<value>:
Transitional behavior at the start of the spline curve (only A or C spline):
BAUTO:
BNAT:
BTAN:
Transitional behavior at the end of the spline curve (only A or C spline):
EAUTO:
ENAT:
594
Command to activate B spline interpolation
Command to activate C spline interpolation
The ASPLINE, BSPLINE and CSPLINE commands are modally effective
and belong to the group of motion commands.
Positions in Cartesian coordinates
Using the PW command, a so-called "point weight" can be programmed for
every point along the curve.
"Point weight"
Range of values: 0 ≤ n ≤ 3
Increment: 0.0001
Effect: n > 1
n < 1
A third degree polygon is used as standard, However, a second degree
polygon can also be used by programming SD=2.
The distances between nodes are suitably calculated internally. The control
can also machine pre-defined node clearances that are specified in the so-
called parameter-interval-length using the PL command.
Parameter interval length
Range of values: As for path dimension
No specifications for the transitional behavior. The start is determined by
the position of the first point.
Zero curvature
Tangential transition to the previous block (delete position)
No specifications for the transitional behavior. The end is determined by the
position of the last point.
Zero curvature
The checkpoint attracts the curve more
significantly.
The checkpoint attracts the curve less sig‐
nificantly.
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
NC programming