Siemens SINAMICS S120 Function Manual page 490

Function modules
8.7 Position control
Figure 8-7
For linear encoders, the interrelationship between the physical quantity and the neutral
length unit LU is configured using parameter p2503 (LU/10 mm).
Example:
Linear encoder, 10 mm should have a resolution of 1 µm (i.e. 1 LU = 1 µm).
-> p2503 = 10000
Figure 8-8
490
Actual position value sensing with linear encoders
Actual position value processing
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Drive functions