Siemens SINAMICS S150 NEMA Operating Instructions Manual page 676

Functions, monitoring and protective functions
9.4 Extended functions
Evaluating the BERO signal
The positive or the negative edge of the BERO signal can be evaluated:
● Positive edge (factory setting)
For referencing with a positive edge evaluation of the BERO signal, the encoder interface
supplies the position of that reference mark, which is directly detected after the positive
edge of the BERO signal. If, mechanically, the BERO is sized in such a way that the
BERO signal covers the entire width of the encoder zero mark, the required encoder zero
mark will be reliably detected in both traversing directions.
● Negative edge
For referencing with a negative edge evaluation of the BERO signal, synchronization is
realized to the next reference mark after leaving the BERO signal.
Setting referencing
Proceed as follows to parameterize referencing with several zero marks:
1. Using parameter p0493, define the fast digital input to which the BERO is connected.
2. Set the corresponding bit of parameter p0490 to 1.
The signal inversion means that the evaluation uses the negative edge of the BERO
signal.
Referencing procedure
Referencing then proceeds as follows:
1. Via the PROFIdrive encoder interface, the drive receives the request for a reference mark
search.
2. Using the parameterization, the drive determines the zero mark depending on the BERO
signal.
3. The drive provides the (possibly corrected) zero mark position as reference mark via the
PROFIdrive encoder interface.
Note
At high speeds or if the distance between the BERO signal and the following zero mark is
too low, then it is possible that the required, next zero mark is not detected, but instead, a
subsequent one due to the computation time. Due to the known zero mark distance, in this
particular case, the determined position is correspondingly corrected.
When using a measuring gear, the zero mark position depends on the motor revolution. In
this case, a correction is also performed and for each motor revolution a reverse calculation
is made back to the position of the zero mark with the shortest distance between the BERO
signal and the zero mark.
674
Operating Instructions, 12/2018, A5E36652151A
Enclosed Drives