Siemens SINUMERIK 840D sl Programming Manual page 238

Measuring variants
3.3 Measure workpiece (milling)
Measuring the reference
The Reference selection is only displayed when at least to swivel heads are available for
selection. The toggler is not displayed for table kinematics. Generally, this only refers to the Z
dimension relation between the MCS and the WCS! With the setting data
$SCS_MEA_FUNCTION_MASK, the function can be activated via bit 10.
Whereby, the Z dimension of the reference head determines the center point of the measuring
sphere in Z. The zero point of the active settable WO is corrected accordingly when measuring.
In the correction of the vectors, only the two axes of the plane (X, Y for G17) and not the vector
of the tool axis (Z) are corrected. The vector of the tool axis remains unchanged as entered
by the machine manufacturer. The data of the active WO is saved for checking later
measurements.
Adapting to the reference
All the length vectors of the head are adapted (X, Y, Z). The zero point of the active WO is
used as reference, which was adapted accordingly with the "Measure reference head"
measuring method. This enables the use of several heads for machining a workpiece. The
operator is responsible for complying with the measuring sequence (first "Measure reference
head", then all other heads with "Adapt head to reference head"). However, a check is made
as to whether the active WO saved for "Measure reference head" is identical for the "Adapt
head to reference head" measuring method.
All of the length vectors of the kinematics are corrected (e.g. from drawing dimensions to real
values).
With an active orientation transformation based on the kinematic chain, the kinematics are
corrected in the correction elements ($NT_CORR_ELEM_T[n,m], $NT_CORR_ELEM_P[n,m])
specified by the machine manufacturer.
Measuring interpolation points
The "VCS Rotary" compile cycle is required for the "Measure interpolation points" function.
The kinematics should always be measured first and then corrected. For machines with very
high demands on precision, it may be necessary to use the more precise compensation via
the "VCS Rotary" compile cycle. The "Measure interpolation points" selection is only displayed
when the "VCS Rotary" compile cycle has also been installed.
Up to twelve measuring points in a uniform measuring grid are recorded for each rotary axis.
A file with a table (one probe length) is generated by CYCLE9960.
Measuring sequence
The deviation in the three geometry axes is determined and saved for each measuring point
in different orientations. Whereby, the compensation is determined and then automatically
saved to a compensation file and activated.
Compensation file
The compensation file is created automatically and save to the manufacturer cycle or user
cycle directory.
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Programming Manual, 12/2017, 6FC5398-4BP40-6BA1
Measuring cycles