Stand-Alone Operation - Siemens SIMATIC S7-400H System Manual

Stand-alone operation

Overview
This appendix provides you with the information for stand-alone operation of a fault-tolerant
CPU. You will learn:
● how stand-alone mode is defined
● when stand-alone mode is required
● what you have to take into account for stand-alone operation
● how the fault tolerance-specific LEDs react
● how to configure stand-alone operation of a fault-tolerant CPU
● how you can expand it to form a fault-tolerant system
The differences from a standard S7-400 CPU that you have to take into account when
configuring and programming the fault-tolerant CPU are given in appendix Differences
between fault-tolerant systems and standard systems (Page 453).
Definition
By stand-alone operation, we mean the use of a fault-tolerant CPU in a standard SIMATIC-
400 station.
Reasons for stand-alone operation
The applications outlined below are only possible when using a fault-tolerant CPU, so they
are not possible with standard S7-400 CPUs.
● Use of fault-tolerant connections
● Configuration of the S7-400F fail-safe automation system
S7-400H
System Manual, 03/2012, A5E00267695-11
A fail-safe user program can only be compiled for execution on a fault-tolerant CPU with
a F-runtime license (for more details refer to the
Systems
manuals).
Note
The self-test of the fault-tolerant CPU is also performed in stand-alone mode.
S7-400F and S7-400FH Automation
B
447