Siemens SINUMERIK 840D sl Programming Manual page 229

Selecting the measuring variant
With variant "Measure at angle" (_MVAR=0x1109) fast calculation of the sphere position is
possible if the sphere diameter is known (low number of measuring points and few
intermediate positioning actions)
"Paraxial measurement" (_MVAR=0x0109) always requires 5 measuring points with more
intermediate positioning actions.
In both types of measurement it is possible to repeat measurement with the located sphere
center point (_MVAR=xxx119). Repeating measurement improves the measuring result.
It is also possible to calculate the sphere diameter (_MVAR=10xx1x9). In this case an
additional measurement is taken parallel to the axis in the plus direction of the abscissa at
the height of the sphere center calculated in the first measurement. Calculation of the sphere
diameter and measurement repetition can be combined (_MVAR=10xx119). Here the
diameter is calculated after each position measurement.
Safe area
All setpoint/actual differences are checked for compliance with the safe area (parameter
_TSA). If this value is exceeded, alarm message "61303 safe area exceeded" appears and
an NC-RESET is needed.
Measurement is then canceled.
If _CBIT[0]=1 the measurement is first repeated.
ZO compensation during measurement of one sphere only (_MVAR=x0x1x9):
The actual value/setpoint differences of the center point coordinates are included the
calculation of the translatory component of the ZO. The offset acts such that the calculated
sphere center point in the offset ZO includes the specified setpoint position (workpiece
coordinates, three axes).
The offset is applied to the ZO number as defined in _KNUM. When KNUM=0, there is no
offset. No scaling factors must be active in the ZOs / frames.
Measuring cycles
Programming Manual, 03/2009 Edition, 6FC5398-4BP10-2BA0
Measuring Cycles for Milling and Machining Centers
5.9 CYCLE997 workpiece: Measuring a sphere and ZO determination
229