Siemens S7-300 - Application 2: Standard Mode with High Availability and Application 4: Safety Mode SIL 2 (Category 3) with High Availability (Only in S7 F;FH Systems)

Digital modules
8.4 SM 326; DI 8 x NAMUR
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
115
8.4.5 Application 2: standard mode with high availability and application 4: safety
mode SIL 2 (Category 3) with high availability (only in S7 F/FH Systems)
Introduction
Below are the wiring scheme and the parameter assignment of SM 326; DI 8 x NAMUR for
● Application 2: standard mode with high availability and
● Application 4: Safety Mode SIL2/Cat.3/PLd with high availability.
Diagnostic messages, possible causes of the problem and their corrective measures are
found in tables in the chapter "Diagnostic Messages for SM 326; DI 8 x NAMUR
(Page 121)".
Wiring scheme of applications 2 and 4
Two single-channel redundant sensors are each connected via one channel to the two digital
modules for each process signal (1oo1 evaluation). The sensor supply Vs is made available
from the respective digital module.
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Figure 8-29 Wiring scheme of the SM 326; DI 8 x NAMUR for applications 2 and 4
WARNING
To achieve SIL2/Cat.3/PLd using this wiring, you must use a suitably qualified sensor.