Siemens SINUMERIK 840D Function Manual page 686

H1: Manual traversing
17.11 Circular travel in JOG
Figure 17-5
Circle segment machining
By specifying a start and end angle, the working area for the 1st and 2nd geometry axis can be
limited to a circle segment:
SD42693 $SC_JOG_CIRCLE_START_ANGLE (circle start angle)
SD42694 $SC_JOG_CIRCLE_END_ANGLE (circle end angle)
Furthermore, the direction from the start to the end angle must be specified to permit the unique
definition of the circle segment:
SD42692 $SC_JOG_CIRCLE_MODE, bit 0
This bit also specifies the traversing direction along the circular path.
686
Circular travel in JOG: Internal/external machining
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA