Parameters For Checking The Measurement Result And Offset - Siemens SINUMERIK 840D sl Programming Manual

2.10

Parameters for checking the measurement result and offset

For constant deviations not subject to a trend, the dimensional deviation measured can be
compensated by an empirical value in certain measuring variants.
For other compensations resulting from dimensional deviations, symmetrical tolerance bands
are assigned to the set dimension which result in different responses.
Empirical value / mean value EVN (S_EVNUM)
The empirical values are used to suppress dimensional deviations that are not subject to a
trend.
Note
If empirical values are not to be applied, then S_EVNUM = 0 must be set.
The empirical values themselves are saved in channel-specific SD 55623
$SCS_MEA_EMPIRIC_VALUE .
EVN specifies the number of the empirical value memory. The actual/set difference determined
by the measuring cycle is corrected by this value before any further correction measures are
taken.
This is the case:
● For workpiece measurement with automatic tool offset.
● For single-point measurement with automatic work offset.
● For tool measurement.
The mean value only refers to the workpiece measurement with automatic tool offset.
For an automatic tool offset, the mean value is generated from the measured difference of the
previous and the actual measurement. This functionality has special significance within a
machining series with measurements performed at the same measuring location.
The function does not have to be activated.
The mean values are stored in the channel-specific SD 55625
$SCS_MEA_AVERAGE_VALUE . The number of the mean value memory is transferred in the
measuring cycle using variable S_EVNUM.
Safe area TSA (S_TSA)
The safe area is effective for almost all measuring variants and does not affect the offset value;
it is used for diagnostics.
Measuring cycles
Programming Manual, 12/2017, 6FC5398-4BP40-6BA1
2.10 Parameters for checking the measurement result and offset
Description
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