Siemens SINUMERIK 840D sl Function Manual page 123

TCOFR/TCOABS frame rotation
A frame rotation does not take place on activation and a rotation which is already active is not
changed. As in case T (only the tool can be rotated), the position of the rotary axes used for the
calculation is dependent on the G command TCOFR/TCOABS and determined from the rotation
component of an active frame or from the entries $TC_CARRn.
Activation of a frame changes the position in the workpiece coordinate system accordingly,
without compensating motion by the machine itself. The ratios are shown in the figure below:
Figure 2-39
Example
On the machine in the figure, the rotary axis of the table is pointing in the positive Y direction.
The table is rotated by +45 degrees. PAROT defines a frame, which similarly describes a
rotation of 45 degrees about the Y axis. The coordinate system is not rotated relative to the
actual environment (marked in the figure with "Position of the coordinate system after TCARR"),
but is rotated by -45 degrees relative to the defined coordinate system (position after PAROT).
If this coordinate system is defined with ROT Y-45, for example, and if the toolholder is then
selected with active TCOFR, an angle of +45 degrees will be determined for the rotary axis of the
toolholder.
Rotary table
With rotary tables (kinematic types P and M), activation with TCARR similarly does not lead to
an immediate rotation of the coordinate system (see figure), i.e. even though the zero point of
the coordinate system is offset relative to the machine, while remaining fixed relative to the zero
point of the workpiece, the orientation remains unchanged in space.
Tools
Function Manual, 06/2019, A5E47435126B AA
Zero offset on activation of a rotary table with TCARR
2.8 Tool carriers with orientation capability
W1: Tool offset
123