4. INTERPOLATION FUNCTIONS
“Clockwise”(G02) and “counterclockwise”(G03) on the X
plane or Y
plane) are defined when the X
plane is viewed
in the positive–to–negative direction of the Z
axis or X
respectively) in the Cartesian coordinate system. See the figure below.
Yp Xp Zp
The end point of an arc is specified by address Xp, Yp or Zp, and is
expressed as an absolute or incremental value according to G90 or G91.
For the incremental value, the distance of the end point which is viewed
from the start point of the arc is specified.
The arc center is specified by addresses I, J, and K for the Xp, Yp, and Zp
axes, respectively. The numerical value following I, J, or K, however, is
a vector component in which the arc center is seen from the start point,
and is always specified as an incremental value irrespective of G90 and
G91, as shown below.
I, J, and K must be signed according to the direction.
End point (x,y)
End point (z,x)
End point (y,z)
I0,J0, and K0 can be omitted. When X
, and Z
are omitted (the end
point is the same as the start point) and the center is specified with I, J,
and K, a 360° arc (circle) is specified.
G021; Command for a circle
If the difference between the radius at the start point and that at the
end point exceeds the permitted value in a parameter (No.3410), an P/S
alarm (No.020) occurs.
D Direction of the circular
D Distance moved on an
D Distance from the start
point to the center of arc