Siemens SINUMERIK 840D sl Function Manual page 120

W1: Tool offset
2.8 Tool carriers with orientation capability
The CORRTC function writes lever arm lengths and axis directions on machines with an
orientation transformation in special correction elements. A kinematic chain is described, for
example, with elements of the type OFFSET, which are defined via $ NK_TYPE.
CORRTC works with sections
The two subchains can each be divided into a maximum of four sections:
● Section 1 begins at the starting point of the chain and ends at the first orientation axis.
● Section 2 is the section between orientation axis 1 and orientation axis 2.
● Section 3 is the section between orientation axis 2 and the end of the chain.
The following figure shows an orientable tool carrier with 2 rotary axes.
Figure 2-38
The sections are clearly defined: If the kinematic subchain is executed from its starting point to
its end point, then the first section has the index 1, next has index 2, and so on.
Correction elements
A reference can be made to a constant kinematic chain element (chain element of the type
$NK_TYPE[<n>] = "OFFSET") in each of these sections with the $TC_CARR_CORR_ELEM [,
0 ... 3] system variables. The correction values determined during the machine measurement
are written to the so designated elements with the CORRTC function.
The sequence of references in $TC_CARR_CORR_ELEM[m, 0 ... 3] must correspond to the
sections described above, that is there can only be one chain element in
$TC_CARR_CORR_ELEM[m, 0] which belongs to the offset vector l1, etc.
The reference value is always the corresponding value effective in the tool carrier active when
CORRTC is called. After selection of the tool carrier, changed contents of the stored kinematic
data have no effect on the method of operation of the CORRTC function.
120
CORRTC example
Function Manual, 06/2019, A5E47435126B AA
Tools