12. GRAPHICS FUNCTION
When the actual tool path is not near the center of the screen, method 1
will cause the tool path to be drawn out of the geaphics range if graphics
magnification is not set properly.
To avoid such cases, the following six graphic parameters are prepared;
Graphic range (Max.) X
Graphic range (Max.) Y
Graphic range (Max.) Z
Graphic range (Min.) X
Graphic range (Min.) Y
Graphic range (Min.) Z
With the above parameters, the center of screen (Gcx, Gcy, Gcz) is
determined by the CNC as follows;
Gcx = (X (MAX.) + X (MIN.) ) /2
Gcy = (Y (MAX.) + Y (MIN.) ) /2
Gcz = (Z (MAX.) + Z (MIN.) ) / 2
The unit of the value will be 0.001 mm or 0.0001 inch depending on the
Graphics magnification is applied automatically. When the graphics
range is specified, the center coordinates and magnification do not need
to be calculated.
The graphic origin and graphic center point will not be changed even if
the workpiece coordinate origin is changed.
In other words, the workpiece coordinate origin is always consistent with
the graphic origin.
G92 X60. Y90. ;
Graphics origin=workpiece coordinate origin
Graphics point (60mm, 90mm)
As shown in the above example, when the command of G92 is specified, the drawing is moved as indicated
by . The position of the graphics origin or graphics center does not change.
Fig.12.1 (c) Workpiece coordinate origin and graphics origin
2. Setting the maximum
coordinates for the
drawing range in the
D Work coordinate system