Communication Via Fault-Tolerant S7 Connections - Siemens SIMATIC S7-400H System Manual

Communication

14.6 Communication via fault-tolerant S7 connections

14.6 Communication via fault-tolerant S7 connections
Availability of communicating systems
Fault-tolerant communication expands the overall SIMATIC system by additional, redundant
communication components such as CPs and bus cables. To illustrate the actual availability
of communicating systems when using an optical or electrical network, a description is given
below of the possibilities for communication redundancy.
Requirement
The essential requirement for the configuration of fault-tolerant connections with STEP 7 is a
configured hardware installation.
The hardware configuration in both subsystems of a fault-tolerant system must be identical.
This applies in particular to the slots.
Depending on the network used, CPs can be used for fault-tolerant and fail-safe
communication, see Appendix Function modules and communication processors supported
by the S7-400H (Page 457)
Only Industrial Ethernet with the ISO protocol or PROFIBUS without distributed I/O and
ISO-on-TCP as of version 6.0 is supported. Fault-tolerant S7 connections via Industrial
Ethernet with ISO-on-TCP are supported by the integrated PN interface and corresponding
CPs. You require a suitable CP for fault-tolerant S7 connections via Industrial Ethernet with
ISO protocol or via PROFIBUS. These connections are not possible via the internal
PROFIBUS-DP interface.
Only Industrial Ethernet is supported for connecting to PC stations using fault-tolerant S7
connections. To be able to use fault-tolerant S7 connections between a fault-tolerant system
and a PC, you must install the "S7-REDCONNECT" software package on the PC. The
software is part of the SIMATIC Net CD. Communication via ISO-on-TCP is also supported
as of version 8.1.2. Please refer to the product information on the SIMATIC NET PC
software to learn more about the CPs you can use at the PC end.
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S7-400H