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

1.10

Parameters for checking the measurement result and offset

1.10
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 _EVNUM
The empirical values are used to suppress dimensional deviations that are not subject to a
trend.
Note
If you do not want to apply any empirical values, _EVNUM = 0 must be set.
The empirical values themselves are stored in data block (GUD5) in field _EV[ ] empirical
value.
_EVNUM specifies the number of the empirical value memory. The actual/set difference
determined by the measuring cycle is corrected by this valuebefore any further correction
measures are taken.
This is the case:
• for workpiece measurement with automatic tool offset.
• for single-point measurement with automatic zero offset.
• tool measurement.
Mean value _EVNUM is active only for workpiece measurement with automatic tool offset.
When calculating the mean value in a series of machining operations, the mean value
determined by the measurement at the same measurement location on the previous
workpiece can be taken into account (_CHBIT[4]=1).
The mean values are stored in data block (GUD5) in field _MV[ ] Mean value. _EVNUM
specifies the number of the mean value memory in this field.
Safe area_TSA
The safe area is effective for almost all measuring variants and does not affect the offset
value; it is used for diagnostics.
If this limit is reached then the following can be assumed:
• a probe defect, or
• an incorrect setpoint position, or
• an illegal deviation from the setpoint position can be assumed.
Measuring cycles
Programming Manual, Release 04/2006, 6FC5398-4BP10-0BA0
1.10 Parameters for checking the measurement result and offset
General
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