Siemens SINUMERIK 840D sl Programming Manual page 163

Position after end of measuring cycle
After the end of the measuring cycle, the probe (ball circumference) is at a distance _FA
from the measuring surface.
NOTICE
Precise measurement is only possible with a probe calibrated under the measurement
conditions, i.e. working plane, orientation of the spindle in the plane and measuring velocity
are the same for both measurement and calibration. Deviations can cause additional
measuring errors.
Prerequisite
The probe must be called as a tool with a tool length offset.
Tool type, preferably: 710
When using the cycle on a turning machine: set type 5xy and _CBIT[14]=0.
Special procedure for differential measurement
The measuring point is measured twice during differential measurement.
1. With spindle rotated through 180 degrees compared with the position at the beginning of
2. With the spindle position that applied at the beginning of the cycle.
The tool radius of the probe + R or - R is defined as the trigger point defined for the axis
direction.
A multidirectional probe does not have to be calibrated at the beginning of the cycle for
measuring variants.
_MVAR= 1000 or _MVAR=1100
However, with these measuring variants, only the measuring axes _MA=1 or _MA=2 are of
any use.
NOTICE
In the case of great measurement accuracy demands, differential measurement is not
recommended!
Measuring cycles
Programming Manual, 03/2009 Edition, 6FC5398-4BP10-2BA0
the cycle
(rotation of the probe by 180 degrees).
Measuring Cycles for Milling and Machining Centers
5.5 CYCLE978 workpiece: Measuring a surface parallel to the axis
163