Siemens SINUMERIK 840D sl Function Manual page 904

Detailed description
2.4 Frames
the plane surrounded by the other and the third axis. This definition ensures that, in the case
that one of the two programmed angles is towards zero, the defined plane enters the plane,
which is created if only one axis is programmed (e.g., with ROT or AROT).
The diagram shows an example where X and Y are programmed. Y here gives the angle, by
which the X axis must rotate around the Y axis to bring the X axis to the line of intersection
formed by the oblique plane and the XZ plane. The same principle applies for the
programmed value of X.
Note
In the shown position of the oblique plane the value of Y is positive, that of X on the other
hand negative.
The specification of the solid angle does not define the orientation of the twodimensional
coordinate system within the plane (i.e., the angle of rotation around the surface normal
vector). The position of the coordinate system is thus determined so that the rotated first axis
lies in the plane, which is surrounded by the first and third axes of the nonrotated coordinate
system.
This means that
• When programming X and Y the new X-axis lies in the old ZX plane.
• When programming Z and X the new Z-axis lies in the old YZ plane.
• When programming Y and Z the new Y-axis lies in the old XY plane.
If the required coordinate system does not correspond to this basic setting, then an
additional rotation must be performed with AROT....
On programming the solid angles, they are converted into the equivalent RPY or Euler
angles, depending on machine data
MD10600 $MN_FRAME_ANGLE_INPUT_MODE
.
These then appear also in the display.
Frame rotation in tool direction
With the language command TOFRAME, which also existed in older software versions, it is
possible to define a frame whose Z axis points in the tool direction.
An already programmed frame is then overwritten by a frame, which describes a pure
rotation. Any zero offsets, mirrorings or scalings existing in the previously active frame are
deleted.
This response is sometimes interfering. It is often particularly practical to retain a zero offset,
with which the reference point in the workpiece is defined.
The language command TOROT is then also used. This command overwrites only the
rotation component in the programmed frame and leaves the remaining components
unchanged. The rotation defined with TOROT is the same as that defined with TOFRAME.
TOROT is, like TOFRAME, independent of the availability of an orientational toolholder. This
language command is also especially useful for 5-axis transformations.
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Basic logic functions: Axes, coordinate systems, frames (K2)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0