6. Interpolation Functions
6.4 Circular Interpolation
48
Precautions for circular interpolation
(1) The terms "clockwise" (G02) and "counterclockwise" (G03) used for arc operations are
defined as a case where in a right-hand coordinate system, the negative direction is viewed
from the position direction of the coordinate axis which is at right angles to the plane in
question.
(2) When all the end point coordinates are omitted or when the end point is the same position as
the start point, a 360
°
arc (full circle) is commanded when the center is commanded using I, J
and K.
(3) The following occurs when the start and end point radius do not match in an arc command :
(a) Program error (P70) results at the arc start point when error
Δ
R is greater than parameter
"#1084 RadErr".
Start point
Alarm stop
Start point radius
End point radius
End point
#1084 RadErr parameter value 0.100
Start point radius = 5.000
End point radius = 4.899
Error
Δ
R = 0.101
Center
(G91) G02X9.899I 5. ;
Δ
R
(b) Spiral interpolation in the direction of the commanded end point results when error
Δ
R is
less than the parameter value.
Start point
Start point radius
End point radius
End point
#1084 RadErr parameter value 0.100
Start point radius = 5.000
End point radius = 4.900
Error
Δ
R = 0.100
Spiral interpolation
Center
(G91) G02X9.9I 5. ;
Δ
R
The parameter setting range is from 0.001mm to 1.000mm.
