Siemens SIMATIC S7 FH - Programming

Fail-Safe Systems
A5E00085588-03
5-1
5 Programming
5.1 Overview
5.1.1 Structure of the Safety Program
The following figure illustrates the structure of a Safety Program in the
programming device/ES and CPU schematically:
S7 F System
F-SMs
Standard
SMs
User
STEP 7 project
CFC
Standard
F-System
F User’s
Charts
Libraries
Programming device / ES
Hardware
Failsafe Blocks V1_2
Control Blocks
Simulation Blocks
User Blocks
Standard
Program
Safety
Program
The user program in the CPU is usually made up of a standard and a fail-safe
section. The safety functions are programmed in CFC using fail-safe blocks.