Siemens SINUMERIK 840D sl Function Manual page 773

Programming with MOVT is independent of the existence of a toolholder that can be oriented.
The direction of the motion is dependent on the active plane.
It runs in the directions of the vertical axes, i.e. with G17 in Z direction, with G18 in Y direction
and with G19 in X direction. This applies when no orientable toolholder is active and for the
case of an orientable toolholder without rotary tool or with a rotary tool in its basic setting.
MOVT acts similarly for active orientation transformation (3-, 4-, 5-axis transformation).
If in a block with MOVT the tool orientation is changed simultaneously (e.g. active 5-axis
transformation by means of simultaneous interpolation of the rotary axes), the orientation at
the start of the block is decisive for the direction of motion of MOVT.
With an active 5-axis transformation, the path of the tool center point (TCP) is not affected by
the change of orientation, i.e. the path remains a straight line and its direction is determined
by the tool orientation at the start of the block.
If MOVT is programmed, linear or spline interpolation must be active (G0,G1, ASPLINE,
BSPLINE, CSPLINE). Otherwise, an alarm is produced.
If a spline interpolation is active, the resultant path is generally not a straight line, since the
end point calculated by MOVT is treated as if it had been programmed explicitly with X, Y, Z.
A block with MOVT must not contain any programming of geometry axes (alarm 14157).
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. The next rotation is always performed in the
currently rotated coordinate system. This applies both to programing in one block, e.g. with
ROT X... Y... Z..., and when constructing a frame in several blocks, e.g. in the form:
N10 ROT
N20 AROT X...
N30 AROT Z...
In workpiece drawings, inclined surfaces are frequently described by way of solid angles, i.e.
the angles which the intersection lines of the inclined plane form with the main planes (X-Y, Y-
Basic Functions
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Y...
K2: Axis Types, Coordinate Systems, Frames
10.5 Frames
773