Communication Between Fault-Tolerant Systems And Pcs - Siemens SIMATIC S7-400H System Manual

14.6.3

Communication between fault-tolerant systems and PCs

Availability
When fault-tolerant systems are linked to a PC, the availability of the overall system is
concentrated not only on the PCs (OS) and their data management, but also on data
acquisition in the automation systems.
PCs are not fault-tolerant due to their hardware and software characteristics. They can be
arranged redundantly within a system, however. The availability of such a PC (OS) system
and its data management is ensured by means of suitable software such as WinCC
Redundancy.
Communication takes place via fault-tolerant S7 connections.
The "S7-REDCONNECT" software package is required for fault-tolerant communication on a
PC. It supports the connection of a PC to a fiber-optic network with one CP, or to a
redundant bus system with 2 CPs. Always use the latest version of this software.
Only Industrial Ethernet is supported for connecting PC systems. The SIMATIC Net software
V 8.1.2 is required for connection via ISOonTCP. This corresponds to the configuration
TCP/RFC1006 at the PC end.
Note
The PROFINET MRP (Media Redundancy Protocol) for PROFINET ring topologies is not
supported by SIMATIC NET PC modules. System buses as optical two-fiber ring cannot be
operated with MRP.
S7-400H
System Manual, 03/2012, A5E00267695-11
14.6 Communication via fault-tolerant S7 connections
Communication
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