Siemens SINUMERIK 840D sl Programming Manual page 289

Figure 3-36
Length measurement
When measuring the tool length, the probe is applied in the direction of the tool.
The measurement can be performed with and without tool offset. Tool offset means a lateral
shift of the tool from the center of the probe in an offset axis around the tool radius and corrected
by an offset vector.
Measuring cycles
Programming Manual, 12/2017, 6FC5398-4BP40-6BA1
Parallel alignment of tool axis, probe axis and axis of the coordinate system
Measuring variants
3.6 Measure tool (milling)
289