Siemens Sinamics S120 Function Manual page 370

Function modules
7.8 Basic positioner
Flying referencing
Inaccuracies in the actual value acquisition are compensated with flying referencing. This
increases the load-side positioning accuracy.
The mode "flying referencing" (also known as post-referencing, positioning monitoring),
which is selected using a "1" signal at binector input p2597 (select referencing type), can be
used in every mode (jog, traversing block and direct setpoint input for positioning/setting-up)
and is superimposed on the currently active mode. Flying referencing can be selected both
with incremental and absolute measuring systems.
With "flying referencing" during incremental positioning (relative) you can select whether the
offset value is to be taken into account for the travel path or not (p2603).
The "flying referencing" is activated by a 0/1 edge at binector input p2595 (start referencing).
The signal in binector input p2595 (start referencing) must be set during the entire
referencing process otherwise the process is aborted.
Status bit r2684.1 (passive/flying referencing active) is linked with binector input p2509
(activate measurement probe evaluation). It activates measurement probe evaluation.
Binector inputs p2510 (measurement probe selection) and p2511 (measurement probe edge
evaluation) can be used to set which measurement probe (1 or 2) and which measurement
edge (0/1 or 1/0) is to be used.
The measurement probe pulse is used to supply connector input p2660 (home measurement
value) with the measurement via parameter r2523. The validity of the measurement is
reported to binector input p2661 (measurement valid feedback) via r2526.2.
Note
The following must always apply to the "Flying referencing mode" windows:
p2602 (outer window) > p2601 (inner window).
See function diagram 3614 for more information on the "Flying referencing mode" function.
The following then happens:
● If the drive has not yet been homed, status bit r2684.11 (reference point set) is set to "1".
● If the drive has already been homed, status bit r2684.11 (reference point set) is not reset
● If the drive has already been homed and the position difference is less than the inner
368
when starting flying referencing.
window (p2601), the old actual position value is retained.
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
Drive functions