Siemens SIMATIC S7 F, Manual

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Product Overview
Fail-Safe Systems
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Combination of Standard, Fault-Tolerant and Fail-Safe Components
Standard, fault-tolerant (H) and fail-safe (F) components and systems can be used
together as follows:
•
Standard systems, H systems, F Systems and FH Systems can be used
together in a single system.
•
Standard modules and F-I/Os can be used together in a single automation
system.
•
A safety-related F user program can be run together with a non-safety-related
standard user program in a fail-safe (F) or fail-safe, fault-tolerant (FH) system.
The fact that fail-safe (F), fault-tolerant (H) and standard components can be
combined has the following advantages:
•
You can set up a fully integrated automation system in which you can make
use of the innovation of the standard CPUs and, at the same time, use fail-safe
components independently of standard components such as FMs or CPs. You
can configure and program the whole system using standard tools such as
HWCONFIG and CFC.
•
The fact that you can combine standard and fail-safe program parts in a single
CPU reduces acceptance costs because only fail-safe program parts are
subject to acceptance procedures. Maintenance costs can also be reduced by
locating as many functions as possible in the standard section, which can be
modified during operation.