Siemens SINAMICS S120 Function Manual page 467

Step 3: Travel to reference point
Travel to the reference point is started when the drive has successfully synchronized to the
reference zero mark (refer to step 2). Once the reference zero mark has been detected, the
drive accelerates on-the-fly to the reference point approach velocity set in parameter p2611.
The drive moves through the reference point offset (p2600), i.e. the distance between the
zero mark and reference point.
If the axis has reached the reference point, then the actual position value and setpoint are
set to the value specified using connector input p2598 (reference point coordinate) (as
standard, connector input p2598 is connected with adjustable parameter p2599). The axis is
then referenced and the status signal r2684.11 (reference point set) set.
Note
The velocity override is inoperative during this process.
If the braking distance is longer than the reference point offset or a direction reversal is
required as a result of the selected reference point offset, then after detecting the reference
zero mark, the drive initially brakes to standstill and then travels back.
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 specification 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.
Drive functions
Function Manual, (FH1), 01/2013, 6SL3097-4AB00-0BP3
Function modules
7.8 Basic positioner
465