Lec - Siemens SINUMERIK 802D sl Function Manual

Compensation (K3)
11.3 Interpolatory compensation
Linear interpolation between interpolation points
The traversing path to be compensated - defined using the start and end positions - is
divided up into several (number depends on error curve shape) path segments of equal size
(see figure). The actual positions that limit these sub-paths are designated "interpolation
points". A compensation value must be entered for each interpolation point (actual position)
during commissioning. The compensation value applied between two interpolation points is
generated on the basis of linear interpolation using the compensation values for the adjacent
interpolation points (i.e. adjacent interpolation points are linked along a line).
Figure 11-2
Compensation value at reference point
The compensation table should be structured such that the compensation value at the
reference point is "zero". This prevents position jumps occurring when the LEC is activated
(after reference point approach).
11.3.2

LEC

Function
The leadscrew error compensation / measuring system error compensation (LEC) is an axis-
specific compensation.
The principle of the LEC is to modify the axis-specific position actual value by the assigned
compensation value in the interpolation cycle and to apply this value to the machine axis for
immediate traversal. A positive compensation value causes the corresponding machine axis
to move in the negative direction.
The magnitude of the compensation value is not limited and is not monitored. In order to
avoid impermissibly high velocities and accelerations caused by compensation, small
compensation values must be selected. Large compensation values can cause other axis
monitoring functions to output alarms (e.g. contour monitoring, velocity setpoint limitation).
210
Linear interpolation between the interpolation points
Turning, Milling, Nibbling
Function Manual, 11/2012, 6FC5397-1CP10-5BA0