Siemens SINUMERIK 840DE sl Function Manual page 263

Coordinate systems for end face transformations
The workpiece coordinate system and the basic coordinate system are independent of the
world coordinate system in which the kinematic chains are defined.
● The Z axis is parallel to the polar axis (axis CM - see above) and parallel to the longitudinal
axis, if it is defined.
● The geometry axes X, Y and Z are vertical to one another and form a perpendicular
coordinate system in the order 1st, 2nd and 3rd geometry axis.
● If the longitudinal axis ($NT_GEO_AX_NAME[n, 2]) exists, it must always be parallel to the
rotary axis ($NT_ROT_AX_NAME[n, 1]).
● If there are two linear axes, they do not have to be orthogonal to one another.
● If there are three linear axes, two axes must be orthogonal to one another. A third axis can
be at an oblique angle to one of the other two axes. There can only be one axis pair in which
the angle of the two axes is not equal to 90°. An oblique axis cannot be positioned
perpendicularly on another axis.
Kinematic chains for end face transformations
The transmit transformation is activated via the system variable $NT_TRAFO_TYPE =
"TRANSMIT_K".
Definition of the linear axes
● The X-axis is defined via the system variable $NT_GEO_AX_NAME[n,0]. This is the linear
axis of the actual TRANSMIT transformation. In the standard scenario, this axis is vertical
on the polar axis (see above).
● An entry in $NT_GEO_AX_NAME[n, 2] is optional. This axis (typically the Z-axis) is the
longitudinal axis. It must be defined parallel to the rotary axis ($NT_ROT_AX_NAME[n, 1]).
● An entry in $NT_GEO_AX_NAME[n, 1] is optional. This axis (typically the Y-axis) stands
vertically on the radial axis ($NT_GEO_AX_NAME[n, 0]) and the polar axis
($NT_ROT_AX_NAME[n, 1]) in the standard scenario.
This axis (the center offset axis) is generally used to compensate a tool offset in the Y
direction so that machining is possible up to the turning center.
Definition of a rotary axis
● The rotary axis is defined via the system variable $NT_ROT_AX_NAME[n,1]. This axis must
always be available. The direction of rotation of the rotary axis is defined via $NT_CNTRL
Bit 11.
● An offset can be defined via system variable $NT_ROT_AX_OFFSET[n, 0] for the active
TRANSMIT transformation.
Defining the order of the axes
Various settings for the transformation are defined using system variable $NT_CNTRL[n]
(Page 298). With the bits 16-18, it is binary coded how the channel axes that are entered in
$NT_ROT_AX_NAME[n, 1], in $NT_GEO_AX_NAME[n. 0] and in $NT_GEO_AX_NAME[n. 2]
Transformations
Function Manual, 06/2019, A5E47435470B AA
K12 transformation definitions with kinematic chains
4.1 Function description
263