Siemens S7-300 - Configuration with F-Sms in Safety Mode

Configuration options
2.3 Configuration with F-SMs in Safety Mode
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
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2.3 Configuration with F-SMs in Safety Mode
Configuration variants in safety mode
Criteria which determine configuration variants of the F-SMs for operation in safety mode:
● Configuration (central or distributed)
● Safety Integrity Level of the configuration
● Availability of the configuration
CPUs approved for use in S7-300 systems (central configuration)
All F-CPUs of the S7-300 family can be used in a central configuration in safety mode.
Note
You can, however, install the SM 326; DO 8 x DC 24V/2A PM centrally with all F-CPUs of
the S7-300 spectrum with:
 CPU 315F-2 DP, as of order no. 6ES7315-6FF01-0AB0, firmware version V2.0.9
 CPU 317F-2 DP, as of order no. 6ES7317-6FF00-0AB0, firmware version V2.1.4
Approved IMs in ET 200M (distributed configuration)
The IM 153-2/-2 FO interface modules of the ET 200M distributed I/O device support
operation of the fail-safe signal modules in standard mode.
Additional information on the supported IMs is available in the chapter "Preface (Page 3)".
Combinations of fail-safe and standard modules supported for operation in safety mode
WARNING
The applicable precautions against accidental contact for standard components are
sufficient for applications with Safety Integrity Level SIL 2/Cat. 3/PLd and lower (see the
S7-300 Module Data reference manual ).
Applications with Safety Integrity Level SIL 3/Cat. 4/PLe require certain measures beyond
accidental contact protection to prevent hazardous overvoltages of F-circuits via the power
supply and backplane bus, even in the event of a fault. A safety protector is available for
the protection of the central and distributed configuration of F-SMs against negative
influences from the backplane bus.
In order to protect the modules against negative influences from the power supply, Siemens
has issued a set of rules governing the implementation of power supply modules, standard
I/O and F I/O (refer to chapter
PELV for fail-safe modules ).