Siemens SINUMERIK 840D Function Manual page 685

● Only one movement at a time can be carried out in the active plane: either on the arc or
perpendicular to it.
● Regardless of the movements in the active plane, the 3rd geometry axis can be traversed
perpendicular to the active plane.
Note
The radius can only be reduced to zero, i.e. to the center point of the circle. If the radius is then
enlarged again, traversing occurs back in the direction from where the reducing started.
Note
If the current position is the center point of the circle when the function is activated or after a
change to the center point of the circle, then the following applies:
● For a full circle, traversing takes place in the direction of the 2nd geometry axes.
● For a segment of a circle, travel is in the direction of the angle bisector.
Internal or external machining
Depending on the specification in the setting data SD42692 $SC_JOG_CIRCLE_MODE,
internal or external machining takes place:
● Internal machining
– Traversing is only possible within the defined circle.
– The circle radius in SD42691 $SA_CIRCLE_RADIUS is the maximum radius.
● External machining
– Traversing is only possible outside of the defined circle.
– The circle radius in SD42691 $SA_CIRCLE_RADIUS is the minimum radius.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
H1: Manual traversing
17.11 Circular travel in JOG
685