Siemens SINUMERIK 840D sl Programming Manual page 523

All main run variables ($AC_CUTMOD_ANG, $AC_CUTMOD and $AC_CUT_INV) can be
read in synchronized actions. A read access operation from the preprocessing generates a
preprocessing stop.
Modified cutting data:
If a tool rotation is active, the modified data are made available in the following system
variables:
System variable
$P_AD[2]
$P_AD[10]
$P_AD[11]
$P_AD[24]
Note
The data are always modified with respect to the corresponding tool parameters
($TC_DP2[..., ...] etc.) if the function "cutting data modification for rotatable tools" was
activated using the command CUTMOD and a toolholder that can be orientated, which causes
a rotation, is activated.
References
For additional information on the function "cutting data modification for rotatable tools", refer to:
Function Manual Basic Functions; Tool Offset (W1)
Job Planning
Programming Manual, 06/2009, 6FC5398-2BP20-0BA0
7.11 Cutting data modification for tools that can be rotated (CUTMOD)
Significance
Tool nose position
Holder angle
Cut direction
Clearance angle
Tool offsets
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