Siemens Simatic S7-300 CPU 31xC Series User Manual

Appendix
A.4 Safety of electronic control equipment
S7-300, CPU 31xC and CPU 31x: Installation
Operating Instructions, Edition 08/2004, A5E00105492-05
A-31
Which fail-safe systems are available in SIMATIC S7?
Two fail-safe systems are available for integrating safety engineering in the SIMATIC S7
automation systems.
The fail-safe controller S7 Distributed Safety is available for implementing safety concepts in
the area of protection of machine and personnel (e.g. EMERGENCY OFF devices for the
use of processing machines) and in the process industry (e.g. for performing protective
functions for MCE safety devices and burners).
The fail-safe and, in particular, optionally redundant automation system
S7 F/FH systems is perfectly suited for systems in the process technology and the oil
industry.
Fail-safe and redundant S7 FH system
To increase the availability of the automation system and thereby, avoid process interruption
in case of errors in the F system, it is possible to build in fail-safe S7 F systems as optionally
redundant (S7 FH systems). This increase in availability can be achieved via redundancy of
the components (power supply, central module, communication and I/O).
Attainable safety requirements
S7 Distributed Safety F systems and S7 F/FH systems can meet the following safety
requirements:
• Requirement class RC1 to RC6 to DIN V 19250/DIN V VDE 0801
• Safety Integrity Level SIL1 to SIL3 to IEC 61508
• Category Cat.2 to Cat.4 to EN 954-1.
Reference
You can find further information in the Safety Engineering in SIMATIC S7 System
Description manual.

Siemens Simatic S7-300 CPU 31xC Series Specifications

General

Series	S7-300 CPU 31xC
Power Supply	24 V DC
Communication Interfaces	MPI, PROFIBUS DP
Programming Languages	LAD, STL, FBD, SCL
Operating Temperature	0°C to +60°C
Memory	48 KB - 512 KB
Dimensions	40 x 125 x 130 mm (varies by model)