Safe Actual Value Acquisition - Siemens SINAMICS S120 Function Manual

Extended Functions

4.8 Safe actual value acquisition

4.8 Safe actual value acquisition
Supported encoder systems
Safety functions used to monitor movements (e.g. SS2, SOS, SLS and SSM) require safe
actual value acquisition. This function is required for safe acquisition of the actual speed.
The following encoder type is supported:
● Optoelectronic encoder with sin/cos signal
Single-encoder system
Encoders within single-encoder systems are used to generate the failsafe actual values of
the drive. The safety-relevant actual values are generated either directly in the encoder or in
the Sensor Module and are transferred without retroaction to the Control Unit by way of
failsafe communication via DRIVE-CLiQ.
Special feature in the case of linear motors:
The motor encoder (linear scale) of linear motors also acts as load measuring system. Only
one measuring system is required for this reason. The system is connected by way of a
Sensor Module, or directly via DRIVE–CLiQ.
NOTICE
When specifying the standstill tolerance window, observe that failsafe position monitoring
within a single-encoder system only works at a rough resolution with 4 pulses per
revolution.
Figure 4-6
50
Example of a single-encoder system
Function Manual, (FHS) , 07/2007 Edition, 6SL3097-2AR00-0BP0
Safety Integrated