HEIDENHAIN PT 855 for Turning - Manual (Page 71)

II - 3 Encoders and Measured Value Display
POSITIP 855 Technical Information 73
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
HEIDENHAIN. POSITIP can compensate these errors. You can activate er-
ror axis compensation using parameter P40.
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
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:
∆
l = L
A
– L
D
= –0.124 mm
∆
l = –124 µm
Compensation factor k =
∆
l / L
D
= – 200 µm / m = – 200 ppm
Linear axis error compensation: P 41.*
Compensation factor k P 41.* = 0
–99 999 [ppm] < P 41.* < 99 999 [ppm]
Axis error compensation