Siemens SINAMICS S120 Function Manual page 356

Basic functions
7.21 Position tracking
Measuring gear configuration (p0411)
The following points can be set by configuring this parameter:
● p0411.0: Activation of position tracking
● p0411.1: Setting the axis type (linear axis or rotary axis)
Here, a rotary axis refers to a modulo axis (modulo offset can be activated through
higher-level controller or EPOS). With a linear axis, position tracking is mainly used to
extend the position area (see Section Virtual multiturn encoder (p0412)).
● p0411.2: Reset position
Overflows can be reset with this. This is required, for example, if the encoder is turned by
more than 1/2 the encoder range while switched off.
Virtual multiturn encoder (p0412)
With a rotary absolute encoder (p0404.1 = 1) with activated position tracking (p0411.0 = 1),
p0412 can be used to enter a virtual multiturn resolution. This enables you to generate a
virtual multiturn encoder value (r0483) from a singleturn encoder. It must be possible to
display the virtual encoder range via r0483.
Note
If the gear factor is not equal to 1, then p0412 always refers to the motor side. The virtual
resolution, which is required for the motor, is then used here.
For rotary axes with modulo offset, the virtual multiturn resolution (p0412) is preset as p0421
and can be changed.
For linear axes, the virtual multiturn resolution (p0412) is preset as p0421 and extended by 6
bits for multiturn information (max. overflows 31 positive/negative)
If, as a result of extension of the multiturn information, the displayable area of r0483 (2
is exceeded, the fine resolution (p0419) must be reduced accordingly.
Tolerance window (p0413)
After switching on, the difference between the stored position and the actual position is
determined and, depending on the result, the following is initiated:
● Difference within the tolerance window
The position is reproduced based on the actual encoder value.
● Difference outside the tolerance window
Message F07449 is output.
● The tolerance window is preset to quarter of the encoder range and can be changed.
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Function Manual, (FH1), 04/2014, 6SL3097-4AB00-0BP4
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Drive functions