Siemens Sinamics S120 Function Manual page 371

● If the drive has already been homed and the position difference is more than the outer
● If the drive has already been referenced and the position difference is more than the inner
Instructions for data set changeover
Using drive data set changeover (DDS), motor data sets (MDS, p0186) and encoder data
sets (EDS, p0187 to p0189) can be changed over. The following table shows when the
reference bit (r2684.11) or the status of the adjustment with absolute encoders (p2507) is
reset.
In the following cases, when a DDS switch takes place, the current actual position value
becomes invalid (p2521 = 0) and the reference point (r2684.11 = 0) is reset.
● The EDS that is effective for the position control changes.
● The encoder assignment changes (p2502).
● The mechanical relationships change (p2503...p2506)
With absolute encoders, the status of the adjustment (p2507) is also reset, if the same
absolute encoder is selected for the position control although the mechanical relationships
have changed (p2503 ... p2506).
In operating mode, a fault (F07494) is also output.
The following table contains a few examples for data set changeover. The initial data set is
always DDS0.
Drive functions
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
window (p2602), alarm A07489 (reference point offset outside window 2) is output and
the status bit r2684.3 (pressure mark outside window 2) set. No offset to the actual
position value is undertaken.
window (p2601) and less that the outer window (p2602), the actual position value is
offset.
Note
On-the-fly referencing is superimposed on an active operating mode, it is therefore not an
active mode.
In contrast to searches for reference, flying referencing can be carried out superimposed
by the machine process.
As standard, for flying referencing, measuring probe evaluation is used; when enabled,
the measuring probe is selected (p2510) and the edge evaluation (p2511) (in the factory
setting, measuring probe 1 is always the measuring probe, flank evaluation in the factory
setting is always the 0/1 edge).
Function modules
7.8 Basic positioner
369