Siemens SINUMERIK 840D sl Function Manual page 483

Figure 11-11 Interpolation of the compensation vector
The compensation vector must be oriented by programming the direction axes at [1, 0, 0]
before part program block N100. In part program block N100, the end position of the
compensation vector is oriented by programming the direction axes at [0, 0, -1].
The intermediate values are generated by path interpolation of all axes programmed in the
part program block:
• Geometry axes for the movement of the machining head
• Direction axes of the compensation vector
It is necessary to break the movement down into part program blocks N100 and N200,
because an antiparallel orientation of the compensation vector of [1, 0, 0] at the start of the
movement and [-1, 0, 0] at the end of the movement (semi-circle) would otherwise result. In
this case, the interpolator would interpolate only the X coordinate of the compensation vector,
and the orientation of the compensation vector would remain unchanged.
Antiparallel orientation of the compensation vector
When an antiparallel orientation of the compensation vector is programmed in a part program
block, the following alarm is displayed:
• Alarm "75018 Channel
Note
Interpolation of the compensation vector
The interpolation of the compensation vector is not a genuine vector interpolation, as
described above, but results from the interpolation of the actual positions of the direction
axes.
Consequently, if the compensation vector changes due to the workpiece contour, the
interpolation of the direction axes is included in the path interpolation of the geometry axes. In
order to minimize the impact of the direction axes on the path interpolation, it is recommended
to configure the dynamic response of the direction axes at least equal to or greater (by a
factor of approx. 10) than the dynamic response of the geometry axes.
Special Functions
Function Manual, 09/2011, 6FC5397-2BP40-2BA0
number number
Block CLC in programmable direction, error ID: 1"
TE1: Clearance control
11.6 Programming
483