Siemens SINUMERIK 840D sl Function Manual page 903

Definition of frame rotations with solid angles
Where a frame is to be defined to describe a rotation around more than one axis, this is
achieved through chaining individual rotations. A new rotation is hereby always performed in
the already rotated coordinate system.
This applies both to programing in a block, e.g. with ROT X... Y... Z...,
(the sequence of rotations is defined by machine data:
MD10600 $MN_FRAME_ANGLE_INPUT_MODE
and is independent of the sequence of the axis letters in the block)
, and when constructing a frame in multiple blocks, e.g. in the format:
N10 ROT Y...
N20 AROT X...
N30 AROT Z...
In workpiece drawings, oblique surfaces are frequently described by way of solid angles, i.e.,
the angles, which the intersection lines of the oblique plane form with the main planes (X-Y,
Y-Z, Z-X planes) (see figure). The machine operator is not expected to convert these solid
angles into the angles of rotation of a chaining of individual rotations.
For this reason, the language commands ROTS, AROTS and CROTS are used, with which the
rotations can be immediately described as solid angles.
The orientation of a plane in space is defined unambiguously by specifying two solid angles.
The third solid angle is derived from the first two. Therefore, a maximum of 2 solid angles
may be programmed, e.g., in the form ROTS X10 Y15. If a third solid angle is specified, an
alarm will be triggered.
It is permissible to specify a single solid angle. The rotations which are performed with ROTS
or AROTS in this case are identical to those for ROT and AROT.
An expansion of the existing functionality arises only in cases where exactly two solid angles
are programmed.
The two programmed axes define a plane, the non-programmed axis defines the related
third axis of a right-hand coordinate system. Which axis is first and which second is then
unambiguously defined for both programmed axes (the definition corresponds to those found
in the plane definition of G17/G18/G19). The angle programmed with the axis letter of an
axis of the plane then specifies the axis, around which the other axis of the plane must be
rotated in order to move this into the line of intersection, which the rotated plane forms with
Basic logic functions: Axes, coordinate systems, frames (K2)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Detailed description
2.4 Frames
119