Programming instructions

NC Programming 17VRS Motion Blocks
4-17
DOK-MTC200-NC**PRO*V17-ANW1-EN-P
1st Axis [X]
2nd Axis[Y]
3rd Axis
[
Z
]
Abscissa
Ordinate
ZX Plane
YZ Plane
G17
G02
G03
XYPlane
G19
G02
G03
G18
G02
G03
Fig. 4-22: Circular programming according to planes
The radius and the starting angle of the arc is calculated from the starting
point and the center point. Any radius which is determined based on the
end point and the center point and is different is ignored. This means that
the end point can only be used to calculate the final angle. Thus, the pro-
grammed end point may not always lie on the arc. The programmed end
point can therefore differ from the traversed end point.
With incremental data input (G91), the center point and the end point are
expressed relative to the starting point; with absolute input (G90), they are
expressed relative to the current zero point.
When programming uses absolute data input, the value of the starting
point is assigned to the coordinate value of a not programmed address
letter (X, Y, Z, I, J, K); with incremental input, the value 0 is assigned.
If a full circle is programmed, only the center point needs to be entered
since the starting points and end points are identical with a full circle.
The circle or arc is defined by the programmed axis commands and the
interpolation parameters. The starting point of the circle is defined by the
previous NC-block. The end point of the circle is defined by the axis value
data X, Y and Z in the G02/G03 NC-block. The center point of the circle is
defined by entered the interpolation parameters I, J and K or directly via
radius R.
Interpolation parameters I, J, K
Interpolation parameters are assigned to the axes which are used in a
circular interpolation. These parameters are parallel to the axes, and their
signs depend on the direction in which they are oriented relative to the
center point of the circle. Based on DIN 66 025, the interpolation pa-
rameters I, J and K are assigned to axes X, Y and Z.
If coordinate values are not programmed using addresses I, J and K, the
corresponding starting point is assigned with absolute dimension pro-
gramming. With incremental dimension programming, the default value is 0.
With G91 programming, the interpolation parameters define the distance
from the starting point of the circle to the center point; with G90 program-
ming they define the distance from the current zero point to the center
point.