Siemens SINUMERIK 840D sl Programming Manual page 237

_STA1 set angle
The setting in _MA makes all 3 measurement planes possible. The set angle _STA1
therefore refers to the positive direction of the offset axis and is negative in the clockwise
direction, positive in the counterclockwise direction.
The set angle _STA1 specifies the required angle between the edge and the positive
direction of the offset axis. In the case of _STA1=0, the edge is aligned paraxially with
regards to the offset axis after correction.
With measuring variants "Positioning at an angle" (_MVAR=00x105) _STA1 is also used for
positioning. The positioning angle is formed together with _TSA. _STA1 should therefore
deviate only a little from the measured angle.
Prerequisite
The probe must be called as a tool with a tool length offset.
Tool type, preferably: 710
When using the cycle on a turning machine: set type 5xy and _CBIT[14]=0.
Measuring cycles
Programming Manual, Release 04/2006, 6FC5398-4BP10-0BA0
Measuring Cycles for Milling and Machining Centers
5.7 CYCLE998 workpiece: Angle measurement and ZO determination
5-103