Siemens SINAMICS S110 - Page 224

Drive functions
7.3 Function modules
Function Manual
222 Function Manual, 01/2011, 6SL3097-4AB10-0BP3
Example of position area extension
With absolute encoders without position tracking, it must be ensured that the traversing
range is 0 smaller 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 8 encoder
revolutions (p0421 = 8).
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Figure 7-43 Position tracking (p2721 = 24), setting p2504 = p2505 =1 (gear factor = 1)
In this example, this means:
Without position tracking, the position for +/- 4 encoder revolutions about 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.
That means, +/- 131072 encoder revolutions or load revolutions can be reproduced in this
way.
For a rotary axis, a value for p2721 = p0421 is set for an encoder.