Siemens SINUMERIK 840D sl Programming Manual page 105

The axis in which the offset is applied (offset axis) is also specified in _MA (_MA=103 or
MA=203).
If no offset axis is specified (_MA=3), the offset is applied in the abscissa, if necessary, (for
G17: X axis).
Sequence on additional offset axis specification
Additionally specifying the offset axis in _MA (_MA= 102 or _MA= 201) first causes the exact
center of the tool probe to be detected in the offset axis before calibration takes place in the
measuring axis.
An entry in the array is only made for the measuring axis in the selected direction of
measurement.
Position after end of measuring cycle
On completion of calibration, the calibration tool (radius) is _FA from the measuring surface.
Measuring cycles
Programming Manual, 03/2009 Edition, 6FC5398-4BP10-2BA0
Measuring Cycles for Milling and Machining Centers
5.2 CYCLE971 tool: Measuring milling tools, drills
105