Siemens sinumerik 840D sl Function Manual page 75

Activate orientation relative to the path
The extended function "Orientation relative to the path" is activated with the following
machine data:
MD21094 $MC_ORIPATH_MODE > 0 (setting for path relative orientation ORIPATH)
The tool orientation relative to the path is activated in the part program by programming
ORIPATH. A kink in the orientation path, e.g. as can occur at a corner in the contour, can be
smoothed with ORIPATH.
Orientation at block transition
In case of the following machine data, tool orientation is always continuous at a block
transition:
MD21094 $MC_ORIPATH_MODE = 0
With the following machine data a jump in tool orientation can occur at a block transition:
MD21094 $MC_ORIPATH_MODE > 0
A jump in orientation always occurs when either the path tangent or the surface normal
vector does not change smoothly at a block transition.
Deviation from the desired orientation
During the interpolation of the block, the orientation may deviate more or less from the
desired relative orientation. The orientation achieved in the previous block is transferred to
the programmed end orientation using large circule interpolation. The resulting deviation
from the desired relative orientation has two main causes:
1. The end orientation of the previous block refers to the tangent and the normal vector at
2. Not only the tangent, but also the normal vector can change throughout the entire block.
Special functions: 3-Axis to 5-Axis Transformation (F2)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0
the end of the previous block. Both can differ from this at the start of the current block.
Therefore, the start orientation in the current block does not have the same alignment
with respect to the tangent and the normal vector as at the end of the previous block.
This is the case, when circles, splines or polynomials are programmed for the geometry
axes, or when not only a start, but also an end value is programmed for the normal
vector. In this case, the tool orientation must change accordingly during the interpolation
of the block, in order to have the same reference to the path tangent and to the surface
normal vector in each path point.
Detailed description
2.8 Orientation
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