Siemens SINAMICS S120 Function Manual page 94

Description of Safety Integrated functions
4.2 Safety Integrated Extended Functions
Taking into account the slip of an induction motor
For Safety Integrated without encoder (depending on the drive load), as a result of slip
(deviations between electrical and mechanical speed), deviations can occur between the
safely determined electrical speed and the mechanical speed at the motor shaft.
Note
Sudden changes in the current and voltage curve (e.g. sudden change in the setpoint setting
and load) and very small absolute values with a high proportion of noise generally result in
faults of the safe encoderless actual value acquisition and must be avoided.
More detailed information on actual value acquisition without encoder can be found in
Section "Notes regarding setting parameters for safe actual value sensing without encoder
(Page 165)".
Note
Scope of functions
There are fewer Safety Integrated Extended Functions available "without encoder" than "with
encoder" (see Section "Drive monitoring with or without encoder (Page 36)").
Note
Safety Integrated Functions "without encoder" for group drives
The Safety Integrated Functions "without encoder" are also permissible for group drives
(multiple motors connected to one power unit).
"Parking" state for Safety Integrated Extended Functions with encoder
Note
Extended Functions with encoder and "parking"
When a drive object, for which Safety Integrated Extended Functions with encoder are
enabled, is switched to "Park" mode, the Safety Integrated software responds by selecting
STO without generating a separate message. This internal STO selection is displayed in
parameter r9772.19.
Basic Functions
● Basic Functions are available in all control modes with and without encoder for
synchronous and induction motors without any restrictions.
● A safety-related encoder is not required for Basic Functions.
● The Safety Integrated Functions "without encoder" are also permitted for group drives
(multiple motors connected to one power unit).
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Function Manual, 12/2018, 6SL3097-5AR00-0BP1
Safety Integrated