Siemens Sinumerik 840D sl Programming Manual page 291

● In circle blocks and in motion blocks containing rational polynomials with a denominator
degree > 4, it is not permitted to change a tool with active tool radius compensation in cases
where the distance between the tool edge center point and the tool edge reference point
changes. With other types of interpolation, it is now possible to change when a
transformation is active (e.g., TRANSMIT).
● For tool radius compensation with variable tool orientation, the transformation from the tool
edge reference point to the tool edge center point can no longer be performed by means
of a simple zero offset. Tools with a relevant tool point direction are therefore not permitted
for 3D peripheral milling (an alarm is output).
Note
The subject is irrelevant with respect to face milling as only defined tool types without
relevant tool point direction are permitted for this operation anyway. (A tool with a type,
which has not been explicitly approved, is treated as a ball end mill with the specified radius.
A tool point direction parameter is ignored).
Fundamentals
Programming Manual, 01/2015, 6FC5398-1BP40-5BA2
Tool radius compensation
11.8 Tools with a relevant cutting edge position
291