Siemens SINUMERIK 840Di sl Programming Manual page 403

Description
The most important distinguishing features are shown in the following table:
G code
TOWSTD
TOWMCS
TOWWCS
TOWBCS
TOWTCS
TOWWCS, TOWBCS, TOWTCS: The wear vector is added to the tool vector.
Linear transformation
The tool length can be defined meaningfully in the MCS only if the MCS is generated by
linear transformation from the BCS.
Non-linear transformation
If, for example, a non-linear transformation is active with TRANSMIT, the BCS is
automatically applied when the MCS is specified as the chosen coordinate system.
No kinematic transformation and no orientable toolholder
If neither a kinematic transformation nor an orientable toolholder is active, then all the other
four coordinate systems (except for the WCS) are combined. It is then only the WCS, which
is different to the other systems. Since only tool lengths need to be evaluated, translations
between the coordinate systems are irrelevant.
References
For further information about tool offsets, please see:
/FB1/Function Manual Basic Functions; Tool Offset (W1)
Fundamentals
Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
Wear value
Initial value, tool length
Wear value in MCS. TOWMCS is
identical to TOWSTD if no orientable
toolholder is active.
The wear value is converted to the
MCS in the WCS
The wear value is converted to the
MCS in the BCS
The wear value is converted to the
MCS in the tool coordinate system
8.17 Special handling of tool offsets
Active orientable toolholder
Wear values are subject to rotation
Only the vector of the resultant tool
length rotates. Wear is ignored
The tool vector is calculated as with
TOWMCS, i.e., the wear value is
ignored
The tool vector is calculated as with
TOWMCS, i.e., the wear value is
ignored
The tool vector is calculated as with
TOWMCS, i.e., the wear value is
ignored
Tool offsets
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