Siemens SINAMICS S120, Function Manual

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Basic functions
7.24 Terminal Module 41
Drive functions
404
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
7.24.4 Synchronization of the zero marks (SINAMICS mode)
After the drive has been powered up, a static offset is obtained as a result of the random
switch-on instant of the incremental encoder emulation.
This static offset can be corrected using this function. The positions of the zero marks output
at the TM41 are synchronized with the zero marks of the leading encoder. The following
conditions are defined for synchronization:
● The reference mark is located at the position at which both track signals A and B have the
"high" status.
● The zero position is the positive edge of the A track belonging to the reference mark,
which for a positive direction of rotation comes before the zero mark.
Figure 7-22 Example: Zero mark synchronization
Layout of the synchronization:
● After the SINAMICS system has been powered up, the TM41 drive object requests the
zero position of the leading encoder via the encoder interface. The encoder emulation
follows the movements of the leading encoder and outputs the track signals A/B. At this
point in time, no zero mark is output. The edges of the A track are still not in synchronism
with the leading encoder.
● The TM41 receives this position after passing the zero position of the leading encoder.
The output of the track signals is now corrected in such a way that the positive edge of
the A track is in synchronism with the zero position.
● After successful synchronization, the zero mark is output at the zero positions.