S7 Fh Systems Fail-Safe And Fault-Tolerant System - Siemens SIMATIC S7 System Manual

Configurations and Help with Selection
2.2 Configuration of F-Systems
Configuration Example for an S7 F Systems F-System
The following figure illustrates an example of an S7 F Systems F-system.
The S7-400 station with CPU 417-4H is the DP master. The F-CPU exchanges safety-
related data with the fail-safe I/O in the DP slaves. The F-system can be expanded with
additional fail-safe I/O, any number of "standard" DP slaves and standard modules.
Figure 2-4
2.2.3

S7 FH Systems Fail-safe and Fault-Tolerant System

Components of S7 FH Systems
S7 FH Systems refers to a fail-safe and fault-tolerant automation system consisting of at
least the following components:
• S7-400H fault-tolerant system (master and standby) on which a safety program is
• Fail-safe signal modules (F-SMs) in an ET 200M distributed I/O system as switched I/O
2-6
S7 F Systems Fail-safe System
executed
(with optional redundancy)
Safety Engineering in SIMATIC S7
System Manual, 04/2006, A5E00109529-05