Siemens SINUMERIK 840D sl Programming Manual page 101

Figure 3-6
Measuring with reversal of the workpiece (CYCLE974)
With this measuring variant, the actual value of a workpiece with reference to the workpiece
zero in the measuring axis is determined by acquiring two opposite points on the diameter.
The workpiece is positioned by the cycle before the first measurement at the angular position
programmed in parameter α0. After the first measurement, the cycle also automatically
generates the 180 degrees reversal before the second measurement. The mean value is
calculated from both measured values.
A correction of the work offset (WO) is only possible when measuring without reversal (1-point
measurement).
Requirements
● The probe must be calibrated in the measuring directions.
● The probe of type 710 or 580 must be active.
● The cutting edge position can be 5 to 8 and must be suitable for the measurement task.
Note
For the measuring variant "Travel below the center of rotation", measurements can also be
performed without previous calibration if, in the user program, before calling CYCLE 994, the
_CHBIT[7] is set (compatibility to previous releases).
Starting position before the measurement
The probe should be positioned opposite the surface to be measured, above the turning center.
Measuring cycles
Programming Manual, 12/2017, 6FC5398-4BP40-6BA1
Positions of the probe when measuring the outer diameter (CYCLE994) with retraction
path in X and Z
Measuring variants
3.2 Measure workpiece (turning)
101