Siemens SINAMICS S120 Function Manual page 494

Function modules
8.7 Position control
Example of position area extension
With absolute encoders without position tracking, it must be ensured that the traversing
range around 0 is less than half the encoder range, because beyond this range, no unique
reference remains after switching on and off (see description on parameter p2507). This
traversing range can be extended using the virtual multiturn (p2721).
The following diagram illustrates an absolute encoder that can represent eight encoder
revolutions (p0421 = 8).
Figure 8-9
In this example, this means:
● Without position tracking, the position for +/- 4 encoder revolutions around r2521 = 0 LU
can be reproduced.
● With position tracking, the position for +/- 12 encoder revolutions (+/- 12 load revolutions
with load gear) can be reproduced (p2721 = 24).
Practical example:
For a linear axis, the value for p2721 is set to 262144 for an encoder with p0421 = 4096.
This means that +/- 131072 encoder revolutions or load revolutions can be reproduced.
For a rotary axis, a value for p2721 = p0421 is set for an encoder.
494
Position tracking (p2721 = 24), setting p2504 = p2505 =1 (gear ratio = 1)
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Drive functions