
B–61404E/08
14. COMPENSATION FUNCTIONPROGRAMMING
277
Programmed path
S : Single block stop point
S
N1
N2
S
N3
S
Direction of the fourth axis
Fig. 14.11 (e) Point at which a single–block stop occurs
in the normal direction control mode
Before circular interpolation is started, the fourth–axis is rotated so that
the fourth–axis becomes normal to the arc at the start point. During
circular interpolation, the tool is controlled so that the fourth–axis is
always perpendicular to the tool path determined by circular
interpolation.
Center of the arc
Programmed path
The tool is controlled so that the fourth–axis
is always normal to the tool path determined
by circular interpolation.
A rotation command is inserted so
that the fourth–axis becomes
normal to the arc at the start point.
Fig. 14.11 (f) Normal direction control of the circular interpolation
CAUTION
During normal direction control, the fourth axis always
rotates through an angle less than 180 deg. I.e., it rotates
in whichever direction provides the shorter route.