Programming instructions

NC Programming 17VRS Motion Commands, Dimension Inputs
3-15
DOK-MTC200-NC**PRO*V17-ANW1-EN-P
3.6 Plane Selection
Plane selection is an important requirement for correctly performing all
motion commands in an NC-program. It informs the controller of the plane
on which machining is performed in order to permit a correct calculation
of the tool correction values. It also plays a role in circle programming.
Plane Selection 'G17’, 'G18’, 'G19’
The three planes XY, ZX and YZ are formed by the coordinate axes X, Y
and Z of the three-axis coordinate system.
G17 Plane selection XY
G18 Plane selection ZX
G19 Plane selection YZ
The three main axes X, Y and Z form a Cartesian coordinate system
which spans the three planes XY, ZX and YZ; the third of these axes is
always normal to the corresponding plane.
Note:
The meaning of the axes in the coordinate system is specified
by the machine builder in the axis parameters.
The preparatory commands G17, G18 or G19 are used to communicate
the desired machining plane to the NC controller, whereby the tool axis is
always normal to the machining plane. If the position of the tool axis can
be changed for design-related reasons, this also defines the machining
plane.
G17
G18
G19
1st Axis [X]
2nd Axis [Y]
3rd Axis [Z]
Abscissa
Ordinate
XY Plane
ZX Plane
YZ Plane
Fig. 3-14: Machining planes
The tool length correction is always performed in the direction of the tool
axis, which means that the override is normal to the selected machining
plane.
The tool path correction is always generated for the active machining
plane. Canceling the tool path correction causes the machining plane to
be changed. The tool path correction is generated for the new plane fol-
lowing the change.
Circular interpolation is only possible in the active machining plane. Heli-
cal interpolations superimpose linear movement in the direction of the tool
axis onto the circular interpolation taking place in the machining plane.
Tool length correction
Tool path correction
Circular interpolations