HEIDENHAIN PT 855 for Milling - Manual (Page 100)

II - 3 Encoders and Measured Value Display
98 Technical Information POSITIP 855
Axis error compensation
Linear and non-linear errors can occur on the axes of a machine, e.g. errors
in drivescrew pitch or errors caused by axis sag and tilt. These errors can
be detected with a comparator system such as the VM 101 from HEIDEN-
HAIN. POSITIP can compensate these errors. You can activate error axis
compensation using parameter P40.
Linear axis error compensation
A factor that you enter in operating parameter P41.* compensates for this
error.
Example calculation of compensation factor k
Displayed distance: L
D
= 620 mm
Actual distance as determined
with comparator system: L
A
= 619.876 mm
Difference: Dl = L
A
– L
D
= –0.124 mm Dl = –124 µm
Compensation factor k = Dl / L
D
= –200 µm / m = –200 ppm
Axis error compensation: P40.*
Axis error compensation (Off): P40.* = 0
Linear axis error compensation (Linear): P40.* = 1
Non-linear axis error compensation (Non-linear): P40.* = 2
Linear axis error compensation: P41.*
Compensation factor k P41.* = 0
– 99 999 [ppm] < P41.* < 99 999 [ppm]