Achievable Safety Classes with F-I/O
5.2 Safety Functions for Achieving Safety Classes for F-I/O with Inputs
Safety Engineering in SIMATIC S7
5-10
System Manual, 04/2006, A5E00109529-05
Example: Two Redundant Sensors Connected via Two Channels to One F-AI (SIL3/Category 4)
The following figure presents the wiring diagram for an SM 336, AI 6 ☓ 13 bit with 4 mA to
20 mA current measurement range and 2-wire transducer output. The sensor is supplied by
the F-I/O. This wiring enables SIL3/Category 4 to be achieved.
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Figure 5-10 Example: Wiring Diagram for Two Redundant Sensors Connected via Two Channels to
One F-AI (1oo2)
1oo2 Evaluation with High Availability (for S7 FH Systems only)
To achieve high availability, four redundant sensors can be connected to two F-AI in S7 FH
Systems.
