Siemens SINUMERIK 840D sl Programming Manual page 46

Description
2.10 Parameters for checking the measurement result and offset
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.
Note
AUTOMATIC mode
AUTOMATIC operation is interrupted and the program cannot continue. An alarm text
appears to warn the user.
Dimension difference check DIF (S_TDIF)
DIF is active only for workpiece measurement with automatic tool offset and for tool
measurement.
This limit has no effect on generation of the compensation value either. When it is reached,
the tool is probably worn and needs to be replaced.
Note
An alarm text is displayed to warn the operator and the program can be continued by means
of an NC start.
This tolerance limit is generally used by the PLC for tool management purposes (twin tools,
wear monitoring).
Tolerance of workpiece: Lower limit TLL (S_TLL), upper limit TUL (S_TUL)
When measuring workpieces, both parameters are only effective regarding tool offsets.
If, for tolerance parameters TLL, TUL, asymmetrical values are selected, then in the cycles,
setpoint ∅S is adapted so that it lies at the center of a new internally generated symmetrical
tolerance bandwidth. These modified values are saved to the following result parameters:
●
● _OVR[8] - upper tolerance limit
● _OVR[12] - lower tolerance limit
Parameters entered by the user TLL,TUL, ∅S remain unchanged.
Example: TUL= 0.0, TLL= -0.004, ∅S= 10
The following is obtained in the result: _OVR[8] = 0.002, _OVR[12] = -0.002, _OVR[0] = 9.998
If, mean value generation is used for the tool offset, and the measurement difference lies in
the range between "2/3 tolerance of the workpiece" (S_TMV) and the "dimensional difference
monitoring" (S_TDIF), then 100 % of the measurement difference is incorporated as tool offset
46
_OVR[0] - setpoint
Programming Manual, 12/2017, 6FC5398-4BP40-6BA1
Measuring cycles