Machine With Rotary Work Table - Siemens SINUMERIK 828D Function Manual

W1: Tool offset
18.6 Toolholder with orientation capability
Demarcation to 5-axis transformation
If the required functionality specifies that the TCP (Tool Center Point) does not vary in the event of reorientation
with reference to the workpiece, even during interpolation, the 5­axis software is required.
For more explanations on 5-axis transformations, see:
References:
/FB3/ Function Manual, Special Functions; 3- to 5­Axis Transformation (F2)
Specification of the toolholder with orientation capability
The toolholder with orientation capability is represented by a general 5­axis kinematic sequence described by a
data block in the tool compensation memory with a total of 33 REAL values. For toolholders that have two rotary
axes for setting the orientation (e.g. a millhead), 31 of these values are constant.
In the current SW version, a data block in the tool compensation memory is described with a total of 47 REAL
values. For toolholders that have two rotary axes for setting the orientation, 45 of these values are constant.
The remaining two values are variable and are used to specify the orientation. The constant values describe
offsets and directions and setting options for the rotary axes; the variable values describe the angles of the rotary
axes.
18.6.4

Machine with rotary work table

System variables
To date, the angles stored in $TC_CARR13 and $TC_CARR14 were used for the calculation of the active tool
length with TCOABS. This still applies if $TC_CARR21 and $TC_CARR22 do not refer to rotary axes. If
$TC_CARR21 or $TC_CARR22 contains a reference to a rotary axis in the channel, the axis position of the
relevant axis at the start of the current block is used as the angle, rather than the entry in $TC_CARR13 or
$TC_CARR14.
A mixed operating mode is permissible, i.e. the angles can be determined from the entry in the system variables
$TC_CARR13 or $TC_CARR14 for one axis, and from the position of a channel axis for the other.
This makes it possible for machines, on which the axes used to set the toolholder with orientation capability are
known within the NC, to access their position directly, whereas it was previously necessary, for example, to read
system variable $AA_IM[axis] and write the result of the read operation to $TC_CARR13/14. In particular, this
removes the implicit preprocessing stop when reading the axis positions.
Basic Functions
1512
Function Manual, 09/2011, 6FC5397-0BP40-2BA0