Siemens Sinamics S120 Function Manual page 374

Function modules
7.8 Basic positioner
The higher-level control/position control when referencing requires a unique reference
between the encoder zero mark and the machine axis (load/spindle). This is the reason that
the "correct" zero mark is selected using a BERO signal.
Example with a measuring gear
PROFIdrive
encoder interface
Figure 7-19
The diagram shows an application example for using referencing with several zero marks
per revolution with a measuring gear located between the motor/load and encoder.
As a result of the measuring gear, several encoder zero marks appear within one motor/load
revolution. Using the BERO signal, also here, the correct zero mark for referencing can be
selected from the several encoder zero marks.
Preconditions
● The position of the zero mark that has the shortest distance to the position when the
● The appropriate mechanical preconditions must be fulfilled when mounting the BERO.
● Preferred mechanical configuration
● In order to be able to precisely determine the position of the BERO (in relation to the
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CU MoMo
Position
Measuring gear between the motor and encoder
BERO signal switches is to be determined.
The BERO signal covers the zero mark, as in this case, the zero mark selection is
independent of the direction of rotation.
reference position of the encoder) even at higher speeds, this must be connected to a
fast Control Unit input.
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SMC
Motor
Function Manual, (FH1), 01/2012, 6SL3097-4AB00-0BP2
BER O
Gear
2 : 7
Zero mark
Encoder
Drive functions