Siemens SINAMICS S120 Function Manual page 95

Figure 5-11
Two-encoder system
The fail-safe actual values for a drive are provided by two separate encoders. The actual
values are transferred to the Control Unit by means of fail-safe communication via DRIVE-
CLiQ.
For motors without a DRIVE-CLiQ interface, the connection is established by means of
additional Sensor Modules (SMC or SME).
Each measuring system requires a separate connection or a separate Sensor Module.
Figure 5-12
Safety Integrated
Function Manual, (FHS), 11/2009, 6SL3097-4AR00-0BP0
Example of an S120 single-encoder system
Example of an S120 two-encoder system on a linear axis via a ballscrew
Safety Integrated Extended Functions
5.12 Safe actual value acquisition
95