Siemens SIMATIC PCS 7 Parts list manual

SIMATIC
Process Control System PCS 7
Fault-tolerant Process Control
Systems (V8.0)
Function Manual
03/2012
A5E02779471-02
Preface
1
Basics of Fault Tolerance
2
Fault-tolerant Solutions in
PCS 7
3
Advantages of fault-tolerant
components
4
Component Replacement
and Plant Changes
5
Failure, Switchover and
Return of Fault-tolerant
Components
6
Diagnostics
7

Legal information
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DANGER
indicates that death or severe personal injury will result if proper precautions are not taken.
WARNING
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CAUTION
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CAUTION
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NOTICE
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A5E02779471-02
Ⓟ 05/2012 Technical data subject to change
Copyright © Siemens AG 2012.
All rights reserved

Table of contents
1 Preface.........................................................................................................................................................7
2Basics of Fault Tolerance...........................................................................................................................13
2.1 Rationale for using fault-tolerant process control systems..........................................................13
2.2 System-wide availability analyses...............................................................................................15
2.3 PCS 7 redundancy concept.........................................................................................................16
2.4 Overview of the PCS 7 redundancy features..............................................................................19
2.5 Features for the configuration phase...........................................................................................20
2.6 Features for the commissioning and operation phases...............................................................20
2.7 Features for servicing and system expansions...........................................................................22
2.8 Definition of availability................................................................................................................23
2.9 Definition of the standby modes..................................................................................................23
2.10 Redundancy nodes......................................................................................................................24
3 Fault-tolerant Solutions in PCS 7................................................................................................................27
3.1 Solutions for the I/O.....................................................................................................................27
3.1.1 Redundant I/O.............................................................................................................................28
3.1.2 Switched I/O................................................................................................................................30
3.1.3 Components in the distributed I/O...............................................................................................32
3.1.3.1 Redundant interface modules in distributed I/O..........................................................................32
3.1.3.2 Redundant I/O modules...............................................................................................................33
3.1.3.3 Redundant actuators and sensors...............................................................................................34
3.2 Solutions for automation systems................................................................................................35
3.2.1 S7-400H hardware components..................................................................................................36
3.2.2 How the SIMATIC S7-400H AS operates....................................................................................39
3.3 Solutions for communication.......................................................................................................39
3.3.1 Network components...................................................................................................................41
3.3.2 Media Redundancy Protocol.......................................................................................................45
3.3.3 Solutions for the terminal bus......................................................................................................46
3.3.3.1 Connecting PC stations to the terminal bus................................................................................46
3.3.3.2 Fault-tolerant terminal bus...........................................................................................................47
3.3.3.3 Redundant, fault-tolerant terminal bus........................................................................................49
3.3.3.4 Redundant, fault-tolerant terminal bus based on the Parallel Redundancy Protocol (PRP).......50
3.3.3.5 Redundant, fault-tolerant terminal bus based on the INTEL TEAM mode..................................52
3.3.4 Solutions for the plant bus...........................................................................................................56
3.3.4.1 Connecting PC stations to the plant bus.....................................................................................56
3.3.4.2 Fault-tolerant plant bus................................................................................................................57
3.3.4.3 Redundant, fault-tolerant plant bus.............................................................................................59
3.3.5 Solutions for the fieldbus.............................................................................................................62
3.3.5.1 Redundant PROFIBUS DP..........................................................................................................62
3.3.5.2 Fault-tolerant fieldbus based on PROFINET...............................................................................64
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3.3.5.3 Gateway between redundant and non-redundant PROFIBUS DP..............................................65
3.3.5.4 Connection of PROFIBUS PA to PROFIBUS DP........................................................................66
3.3.5.5 Fault-tolerant PROFIBUS PA......................................................................................................68
3.3.5.6 Connecting the FOUNDATION Fieldbus to PROFIBUS DP........................................................72
3.3.5.7 Fault-tolerant FOUNDATION Fieldbus........................................................................................74
3.4 Solutions for integrating a PCS 7 plant in a domain....................................................................77
3.5 Solutions for OS servers..............................................................................................................77
3.6 Solutions for OS clients...............................................................................................................81
3.6.1 Additional OS clients...................................................................................................................81
3.6.2 Permanent operability..................................................................................................................81
3.7 Solutions for SIMATIC BATCH....................................................................................................82
3.8 Solutions for Route Control server..............................................................................................85
3.9 Solutions for engineering station.................................................................................................87
3.10 Time synchronization...................................................................................................................88
4 Advantages of fault-tolerant components...................................................................................................89
4.1 Creating and expanding a project with pre-configured stations..................................................89
4.2 SIMATIC H Station......................................................................................................................89
4.2.1 Overview of configuration tasks...................................................................................................89
4.2.2 How to add a SIMATIC H station to your project.........................................................................90
4.2.3 How to insert synchronization modules into the H CPU..............................................................91
4.2.4 How to configure redundant communication processors.............................................................93
4.2.5 How to set the failure reaction of the input/output modules on the CPU.....................................95
4.3 Communication connections.......................................................................................................96
4.3.1 Overview of configuration tasks...................................................................................................96
4.3.2 Configuring the connection to the terminal bus...........................................................................97
4.3.2.1 How to configure the redundant terminal bus on the basis of the Parallel Redundancy Protocol97
4.3.2.2 How to configure the redundant terminal bus on the basis of the INTEL TEAM mode ..............97
4.3.2.3 How to connect singular components to the redundant terminal bus on the basis of the Parallel
Redundancy Protocol................................................................................................................100
4.3.3 How to configure a fault-tolerant plant bus................................................................................100
4.3.4 How to configure a redundant PROFIBUS DP..........................................................................102
4.3.5 How to configure a fault-tolerant fieldbus on the basis of PROFINET.......................................105
4.3.6 How to configure the redundant PROFIBUS PA.......................................................................107
4.4 Distributed I/O............................................................................................................................109
4.4.1 Overview of configuration tasks.................................................................................................109
4.4.2 How to configure the redundant interface for the I/O device.....................................................110
4.4.3 How to configure redundant I/O modules..................................................................................112
4.4.4 How to configure the redundancy for HART field devices.........................................................116
4.4.5 How to configure the Y Link.......................................................................................................119
4.4.6 Configuring DP/PA Link.............................................................................................................122
4.4.7 Configuring FF Link...................................................................................................................124
4.4.8 Configuration of redundant signals............................................................................................126
4.5 Operator stations.......................................................................................................................127
4.5.1 Overview of configuration tasks.................................................................................................127
4.5.2 How to configure an OS server and its redundant OS partner server.......................................127
4.5.3 How to configure a central archive server and its redundant archive partner server................130
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4.5.4 How to set the redundancy of the central archive server..........................................................133
4.5.5 How to set the project paths of the destination OS and standby OS........................................134
4.5.6 How to configure a redundant connection between an OS and AS..........................................135
4.5.7 How to configure redundancy for OS servers on the engineering station.................................138
4.5.8 How to set the redundancy connection for OS servers.............................................................141
4.5.9 How to assign an S7 program to an OS....................................................................................142
4.5.10 How to configure an OS client...................................................................................................144
4.5.11 How to configure an OS client for permanent operability..........................................................145
4.5.12 How to download a SIMATIC PCS 7 project to the target systems...........................................148
4.5.13 Evaluating the "@RM_MASTER" Redundancy Variables with Scripts......................................149
4.6 SIMATIC BATCH Stations.........................................................................................................149
4.6.1 Overview of configuration tasks.................................................................................................149
4.6.2 How to configure a BATCH server and its redundant BATCH partner server...........................150
4.6.3 How to configure a BATCH client..............................................................................................152
4.6.4 How to set the redundancy monitoring of BATCH servers........................................................153
4.6.5 How to configure the redundancy connection for BATCH servers on the engineering station..154
4.6.6 How to set the redundancy connection for BATCH servers......................................................155
4.6.7 How to download the target systems for SIMATIC BATCH.......................................................156
4.7 SIMATIC Route Control stations...............................................................................................157
4.7.1 Overview of configuration tasks.................................................................................................157
4.7.2 How to configure a Route Control server and its redundant Route Control partner server.......157
4.7.3 How to configure a Route Control client....................................................................................160
4.7.4 How to configure a redundant connection between a Route Control server and AS................162
4.7.5 How to set the redundancy connection for Route Control servers............................................165
4.7.6 How to set the redundancy of the Route Control servers..........................................................166
4.7.7 How to download the target systems for Route Control............................................................166
5 Component Replacement and Plant Changes.........................................................................................167
5.1 Failure and replacement of bus components............................................................................167
5.1.1 Replacement of SIMATIC components in runtime....................................................................167
5.1.2 Replacement of bus components in runtime.............................................................................168
5.1.3 Replacement of operator stations in runtime.............................................................................169
5.1.4 Replacement of BATCH stations in runtime..............................................................................170
5.1.5 Replacement of Route Control stations in runtime....................................................................171
5.2 Plant changes in runtime...........................................................................................................172
6 Failure, Switchover and Return of Fault-tolerant Components.................................................................175
6.1 I/O..............................................................................................................................................175
6.1.1 Failure of redundant interface modules.....................................................................................175
6.1.2 Failure of redundant I/O modules..............................................................................................175
6.2 Automation system....................................................................................................................177
6.2.1 Failure of the master CPU.........................................................................................................177
6.2.2 Failure of a fiber-optic cable......................................................................................................178
6.3 Communication..........................................................................................................................180
6.3.1 Failure of redundant bus components.......................................................................................180
6.4 OS server..................................................................................................................................181
6.4.1 Failure, failover and restarting of redundant OS servers...........................................................181
6.5 BATCH Server...........................................................................................................................186
6.5.1 Reaction of BATCH servers to failure........................................................................................186
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6.6 Route Control server.................................................................................................................187
6.6.1 Reaction of Route Control servers to failure..............................................................................187
6.7 OS clients..................................................................................................................................188
6.7.1 Failover reactions of OS clients with permanent operability......................................................188
6.8 BATCH clients...........................................................................................................................190
6.8.1 Failover reactions of BATCH clients..........................................................................................190
6.9 Route Control clients.................................................................................................................190
6.9.1 Failover reaction of Route Control clients..................................................................................190
6.10 Guidelines for updating a redundant OS in runtime..................................................................191
6.10.1 Introduction................................................................................................................................191
6.10.2 Overview of the required tasks..................................................................................................193
6.10.3 Phase 1: Updating Server_2......................................................................................................196
6.10.4 Phase 2: Updating OS clients interconnected with Server_2....................................................199
6.10.5 Phase 3: Downloading the connections, gateways and changes to the AS..............................201
6.10.6 Phase 4: Updating the OS clients interconnected with Server_1..............................................202
6.10.7 Phase 5: Updating Server_2......................................................................................................204
6.11 Guide to updating a redundant BATCH server in runtime.........................................................207
6.11.1 Software update (migration)......................................................................................................207
6.12 Guide to updating a redundant Route Control server in runtime...............................................207
6.12.1 Updating a redundant Route Control server in runtime.............................................................207
7 Diagnostics...............................................................................................................................................209
Index.........................................................................................................................................................211
Table of contents
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Preface 1
Purpose of this documentation
This documentation informs you about the following aspects of configuring fault-tolerant
systems with the SIMATIC PCS 7 Process Control System:
● The basic solution concepts
● The functional mechanisms
● The most important configurations
It presents the availability solutions on all automation levels (management, process, field).
You will find references to other product manuals containing specific information for working
with individual components.
Options for accessing PCS 7 documentation
Note
PCS 7 Readme
The information given in the PCS 7 Readme on the Internet takes precedence over all the
PCS 7 manuals. Please read this PCS 7 Readme carefully; it contains important information
and amendments on PCS 7.
● The PCS 7 Readme on the Process Control System; SIMATIC PCS 7 DVD contains
important information regarding PCS 7 and takes precedence over the PCS 7
documentation supplied.
● After installation of PCS 7, you can find documents such as Process Control System PCS
7; PCS 7 Readme and What's New in PCS 7? via the submenu SIMATIC > Product
Information > <Language>.
As of PCS 7 V8.0, you receive basic PCS 7 system documentation with the Process Control
System; SIMATIC PCS 7 DVD.
The PCS 7 Internet site http:\\www.siemens.com/pcs7-documentation (http:\
\www.siemens.com/pcs7-documentation) provides convenient access to the complete PCS 7
documentation. You can find the following for the latest PCS 7 versions:
Fault-tolerant Process Control Systems (V8.0)
Function Manual, 03/2012, A5E02779471-02 7

●In the section "Hardware manuals for SIMATIC PCS 7 ..."
– The manuals for components approved for a PCS 7 version
●In the section "Software manuals for SIMATIC PCS 7 ..."
– The complete system documentation
– The separate setup program for PCS 7 documentation and the PCS 7 help system for
download. After the installation of the setup program, you will find the documentation at
the following locations on the Engineering Station:
- As online help (CHM file) for the SIMATIC Manager application
- As a PDF file in the Windows Start menu with the SIMATIC documentation
– The complete documentation for PCS 7 as a Manual Collection
Validity of the documentation
This documentation is valid for the software package
Process Control System; SIMATIC
PCS 7 , V8.0 or higher.
Required basic knowledge
General knowledge in the area of automation engineering and basic knowledge of PCS 7 is
required to understand this documentation. It is also assumed that the reader knows how to
use computers or other equipment similar to PCs (such as programming devices) with the
Windows operating system.
The configuration manuals and the Getting Started documentation for PCS 7 will provide you
with basic information regarding the use of PCS 7.
Position in the information landscape
The following documentation provides more information about fault-tolerant process control
systems and the handling of the individual components. This documentation is part of the PCS
7 software.
Manual Content
Getting Started Process Control
System PCS 7; Part 1 - Getting
Started
● Creating projects
● Working with the CFC Editor
● Working with the Import/Export Wizard
● Working with the SFC Editor
● Compiling, downloading and testing
● Working with the operator station
Configuration manual Process
Control System PCS 7; Engineering
System
● Basics of PCS 7
● Creating projects
● Configuring hardware
● Configuring networks
Preface
Fault-tolerant Process Control Systems (V8.0)
8Function Manual, 03/2012, A5E02779471-02

Manual Content
Configuration manual Process
Control System PCS 7; Operator
Station
● Configuring SIMATIC connections
● Interconnecting faceplates
● Configuring operator stations
● Compiling the OS
● Installation guidelines
Process Control System PCS 7;
Maintenance Station function
manual
● Activation of the maintenance functions
● Configuration of redundancy
● Adding the OPC server
Configuration manual WinCC ● Getting Started
● Operating principle of WinCC redundancy
● User archives
● Creating the "Project_Redundancy_Server" example project
● Description of the WinCC projects
● Server project
Manual WinCC Hardware Options,
Part 3 Redundancy
● Structure of a redundant WinCC system
● Operating principle of WinCC redundancy
● Configuring the OS server pair
● Guide for setting up a redundant system
● Entering the servers in Windows
Manual
Process Control System PCS 7;
SIMATIC BATCH
● Structure of a redundant BATCH system
● Configuring the BATCH server pair
● Installation guidelines
Manual
Process Control System PCS 7;
SIMATIC Route Control
● Setting up a redundant Route Control system
● Configuring the Route Control server pair
● Installation guidelines
Manuals for PCS 7 Software Update ● Updating a PCS 7 Project with and without use of new
functions
● Upgrading a redundant system during online operation
Manual Automation System
S7-400H, Fault-tolerant Systems
● Redundant SIMATIC automation systems
● Increasing availability
● System and operating modes of the S7-400H
● Linking and updating
Manual Modifying the System in
Runtime via CiR
● Modifying standard systems in runtime
Manual Distributed I/O Device ET
200M
● Configuration options
● Mounting
● Wiring
● Commissioning and diagnostics
Manual Distributed I/O Device ET
200iSP
● Configuration options
● Mounting
● Wiring
● Commissioning and diagnostics
Preface
Fault-tolerant Process Control Systems (V8.0)
Function Manual, 03/2012, A5E02779471-02 9

Manual Content
Operating Instructions SIMATIC
NET; Industrial Ethernet Switches
SCALANCE X-200
● Configuration options
● Mounting
● Wiring
● Commissioning and diagnostics
Operating Instructions SIMATIC
NET; Industrial Ethernet Switches
SCALANCE X-400
● Configuration options
● Mounting
● Wiring
● Commissioning and diagnostics
Manual SIMATIC NET Manual
Industrial Twisted Pair and Fiber-
Optic Networks
● Networks with Industrial Ethernet and Fast Ethernet
● Network configuration
● Passive components for electrical and optical networks
● Active components and topologies
Manual SIMATIC Diagnostic
Repeater for PROFIBUS-DP
● Configuration options
● Mounting
● Wiring
● Commissioning and diagnostics
Manual SIMATIC DP/PA Coupler,
DP/PA Link and
Y Link
● Fundamentals of PROFIBUS PA
● DP/PA Coupler
● DP/PA Link
● DP/PA Link in redundant operation with the S7-400H
Documentation
PCS 7 - Released Modules
● Components released for redundancy in PCS 7
Guide
This manual is organized into the following topics:
● Basics of fault-tolerance in PCS 7
● Description of fault-tolerant solutions in PCS 7
● Description of configurations for various redundant components in PCS 7
● Failure scenarios and diagnostic options
● Options for quantitative analysis of fault-tolerant process control systems
● Glossary with important terms for understanding this documentation
● Index of important keywords
Conventions
In this documentation, the names of elements in the software interface are specified in the
language of this documentation. If you have installed a multi-language package for the
operating system, some of the designations will be displayed in the base language of the
operating system after a language switch and will, therefore, differ from the designations used
in the documentation.
Preface
Fault-tolerant Process Control Systems (V8.0)
10 Function Manual, 03/2012, A5E02779471-02

Changes compared to the previous version
Below, you will find an overview of the most important changes in the documentation compared
to the previous version:
● Using the redundant, fault-tolerant terminal bus
For additional information, refer to the section "Solutions for the terminal bus (Page 46)."
● Using the Process Historian and Information Server for central archiving
For additional information on this topic, refer to the
SIMATIC HMI; SIMATIC Process
Historian documentation.
● Using a fault-tolerant fieldbus based on PROFINET
For additional information, refer to the section "Fault-tolerant fieldbus based on
PROFINET (Page 64)."
● Using the redundant FOUNDATION Fieldbus
You can find information about this in the "Fault-tolerant FOUNDATION Fieldbus
(Page 74)" section
Preface
Fault-tolerant Process Control Systems (V8.0)
Function Manual, 03/2012, A5E02779471-02 11

Basics of Fault Tolerance 2
2.1 Rationale for using fault-tolerant process control systems
Advantages of fault-tolerant components
Process control systems are responsible for controlling, monitoring and documenting
production and manufacturing processes. Due to the increasing degree of automation and the
demand for improved efficiency, the availability of these systems is playing an increasingly
important role.
Failure of the control system or any of its components can lead to costly downtime in production
and manufacturing. The expense involved in restarting a continuous process also has to be
taken into consideration along with the actual production losses resulting from a failure. In
addition, the loss of an entire batch may occur due to lost quality data. If the process is intended
to operate without supervisory or service personnel, a process control system must be
configured fault-tolerant for all of the components.
You can minimize the risk of a production failure and other detrimental effects by using fault-
tolerant components in a process control system. A redundant design ensures increased
availability of a control system. This means that all components involved in the process have
a backup in continuous operation that simultaneously participates in the control tasks. When
a fault occurs or one of the control system components fails, the correctly operating redundant
component takes over the continuing control task. The ultimate goal is to increase the fault
tolerance and fail-safe performance in process control systems.
The following applies to you as the plant operator:
The higher the cost of a production stoppage, the more you need a fault-tolerant system. The
higher initial investment usually associated with a fault-tolerant system is soon offset by the
savings resulting from decreased production downtimes.
Fault-tolerant PCS 7 process control system
The following components of the PCS 7 process control system allow you to implement fault-
tolerance at all automation levels in the form and to the degree you require:
● Operator stations, maintenance station, central archive server, BATCH stations, Route
Control stations (management level)
● Bus system
● Automation systems (process level)
● Distributed I/O (field level)
The following figure shows an example of a fault-tolerant process control system with PCS 7
components.
Fault-tolerant Process Control Systems (V8.0)
Function Manual, 03/2012, A5E02779471-02 13

7HUPLQDOEXV3ODQWEXV%$7&+FOLHQWV06VHUYHU5RXWH&RQWUROVHUYHU6HQVRU6HQVRU26FOLHQWV5RXWH&RQWUROFOLHQWV26VHUYHU%$7&+VHUYHU(QJLQHHULQJ6WDWLRQ06FOLHQW)LHOGEXV&3
&3
&336&3&3836&3,036(70,036,0&386060606060606060606060606+,0&3&33636(70
Legend for the above illustration:
Note
The following short designations are commonly used in this documentation.
Basics of Fault Tolerance
2.1 Rationale for using fault-tolerant process control systems
Fault-tolerant Process Control Systems (V8.0)
14 Function Manual, 03/2012, A5E02779471-02

Short designation Meaning
Engineering
Station
Engineering station, PC
OS server Operator station, PC project data station in the project form "WinCC Server"
OS client Operator station, PC visualization station in the project form "WinCC Client"
BATCH server BATCH station, PC recipe and batch data station
BATCH client BATCH station, PC recipe creation and batch visualization station
Route Control
server
Route Control station, PC Route Control data station
Route Control
client
Route Control station, PC Route Control visualization station
Plant bus, terminal
bus
Bus systems for communication over Industrial Ethernet (electrical or optical)
S7-400H SIMATIC S7 fault-tolerant automation system, or H system for short
PS Power supply
CPU Central processing unit
CP Communications processor
IM Interface module
SM Signal module / I/O module in analog or digital form
ET 200M Distributed I/O device
Fieldbus Fieldbus for distributed I/O
Sensor Transmitters, sensors
2.2 System-wide availability analyses
Introduction
Availability must be analyzed globally for the system as a whole. Based on the degree of
availability needed, each system level, each system and each component within a level should
be evaluated. It is important to know the importance of each of these for the availability
requirements as well as the ways and means that the required availability will be achieved.
Avoiding repair time
In many industrial processes, it is not enough to simply correct the failure of a component and
then continue the process. The repair has to be made without interruption to the continuing
production process. The repair time can be considerably reduced by keeping replacement
parts in stock on site. The use of fault-tolerant components in the process control system
enables you to correct the cause of the system or component failure in runtime. The function
of the component is retained if no fault occurs in the remaining active (redundant) components
during the time a failed counterpart component is being repaired. That is, the plant continues
operation without disruption.
Basics of Fault Tolerance
2.2 System-wide availability analyses
Fault-tolerant Process Control Systems (V8.0)
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Avoiding impermissible signal edge transitions
A reserve system with connected backup I/O may not cause an impermissible signal edge
transition when a change occurs in the operating state (power on or off) or operating mode
(master or slave).
2.3 PCS 7 redundancy concept
Advantages of the PCS 7 redundancy concept
Fault-tolerant process control systems can be realized with SIMATIC PCS 7 at minimal cost
in all phases of a system lifecycle:
● Configuration
● Commissioning/operation
● Servicing
● Expansion
PCS 7 offers the following essential advantages:
● It provides you with system-wide scalable solutions based on the PCS 7 modular design.
Advantage: The availability can be matched to your requirements. Your process control
system can be upgraded with the SIMATIC PCS 7 components that are actually needed.
● Hardware upgrades for fault tolerance do not depend on the software configuration.
Advantage: If the user program has been configured with PCS 7, it does not have to be
adapted following a hardware upgrade. You only need to download the new hardware
configuration into the CPU.
● Fault-tolerant automation system S7-400H with CPU (types: see documentation
Process
Control System PCS 7; Released Modules ), whose module racks can be set up in separate
locations.
Advantage: Protection for the spatially separated CPUs resulting in increased availability
in case of fire or explosion, for example.
● The use of redundant components in the process control system means isolated errors are
tolerated.
Advantage: The entire system does not fail when a single component in the process control
system fails. The redundant component takes over its tasks therefore allowing the process
to continue.
● Every failure of a redundant component is indicated on the OS clients in the form of a
process control message.
Advantage: You immediately receive crucial information about the status of your redundant
component. Specific components that have failed can be quickly replaced to restore the
redundancy.
● Software updates on redundant OS servers can be performed without loss of process
operability or loss of data.
Basics of Fault Tolerance
2.3 PCS 7 redundancy concept
Fault-tolerant Process Control Systems (V8.0)
16 Function Manual, 03/2012, A5E02779471-02

Overview of the PCS 7 redundancy concept
PCS 7 offers you a redundancy concept that reaches all levels of process automation.
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The numbering of the components in the illustration relates to the descriptions provided below.
Basics of Fault Tolerance
2.3 PCS 7 redundancy concept
Fault-tolerant Process Control Systems (V8.0)
Function Manual, 03/2012, A5E02779471-02 17

Number Description
1 Several clients (OS clients, BATCH clients, Route Control clients) can access data on a
server (OS server, BATCH server, Route Control server).
2 Communication between the operator stations (client and server) and communication with
the engineering station is over a redundant, fault-tolerant terminal bus (Industrial Ethernet).
The clients and server are connected to the terminal bus via switches.
3 The servers (OS server, BATCH server, Route Control server, maintenance server, central
archive server) can, when necessary, be set up redundantly.
4 Automation systems communicate with the OS servers/Route Control servers and
engineering stations and among themselves over the redundant, fault-tolerant plant bus
(Industrial Ethernet).
The automation systems, server and engineering station are connected to the plant bus via
switches.
5 Each part of the redundant, fault-tolerant S7-400H automation systems is connected to the
plant bus with an Ethernet communications processor (CP).
Each part of the AS be connected to several PROFIBUS DP chains. The internal PROFIBUS
DP interfaces or additional communications processors are used for the attachment.
6 The redundant connection to the DP master system is achieved using two 153-2 IM modules
in each ET 200M.
Equivalent connection via PROFINET - You can find information about this in the section
"Fault-tolerant fieldbus based on PROFINET (Page 64)"
7 Using redundant digital or analog input/output modules, you can evaluate signals from
sensors/actuators. If one of the two redundant modules fails, the input/output signal of the
functioning module are evaluated.
8 Fieldbus systems can be connected to the redundant PROFIBUS DP.
The configuration of a redundant fieldbus can be realized with a redundant gateway (for
example, PA link). The field devices are connected to the subsystem (for example,
PROFIBUS PA) via AFD, active field distributors, (or AFS when ring/coupler redundancy is
used).
9 The Y Link allows you to connect non-redundant PROFIBUS distributed I/O devices to a
redundant PROFIBUS DP.
Illustration of fault tolerance using redundancy nodes
Redundancy nodes can be used to provide an overview of the fault tolerance of a process
control system. As an introductory example, the following illustration presents the process
control system shown above as a block diagram with the individual redundancy nodes.
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Basics of Fault Tolerance
2.3 PCS 7 redundancy concept
Fault-tolerant Process Control Systems (V8.0)
18 Function Manual, 03/2012, A5E02779471-02

2.4 Overview of the PCS 7 redundancy features
Introduction
The easiest way to increase availability is to keep replacement parts in stock on site and to
have fast service at your disposal to replace defective components.
In this documentation, we provide you with PCS 7 software and hardware solutions that go
well beyond fast service and replacement part warehousing. It focuses on "automated fault-
tolerant process control systems".
System-wide, scalable solutions in PCS 7 available
Plants are divided into the following layers in PCS 7:
● Field layer
● Process layer
● Management level
The components of PCS 7 enable you to implement fault-tolerant solutions at all automation
system levels in the form and to the degree you desire. In PCS 7, individual components (such
as signal modules), complex systems (such as operator control and monitoring systems) and
complete plants can be configured in such a way that one sub-component can automatically
take on the function of another sub-component if it fails.
You decide which components in the plant require increased availability.
The following table lists the fault-tolerant components for the three layers.
Process layer Components
Management level OS clients, maintenance clients, BATCH clients, Route Control clients
OS servers, maintenance servers, central archive servers, BATCH servers,
Route Control servers
Terminal bus (Industrial Ethernet)
Process layer Plant bus (Industrial Ethernet)
Automation system AS 412H, AS 414H, AS 416H, AS 417H
Field layer Fieldbus PROFIBUS DP, PROFIBUS PA,
Distributed I/O device ET 200M, ET 200iSP
S7-300 distributed I/O modules
PROFIBUS DP, PROFIBUS PA and HART devices
Basics of Fault Tolerance
2.4 Overview of the PCS 7 redundancy features
Fault-tolerant Process Control Systems (V8.0)
Function Manual, 03/2012, A5E02779471-02 19

Basics of increased availability
Increased availability in PCS 7 is based on the following principles:
● Duplication of a component
Example:
Use of duplicate signal modules
● Duplication of a component and a software component that performs an automatic failover
from active and passive components when a fault occurs.
Example of redundant components:
A signal is acquired with two signal modules and the redundancy software. The failure of
one module remains non-critical for operation of the plant.
● Technical solutions for configuring components that prevent the failure of a sub-component.
Example:
Configuration of a network in a ring structure with a component as redundancy manager.
If part of the ring is disrupted (by a defective cable, for example), the operation of the network
is maintained.
2.5 Features for the configuration phase
Features for the configuration phase
In the configuration phase, PCS 7 provides you with support with the following features.
Feature Meaning
Fault prevention through simplified
configuration of the various components
You do not need additional training to configure the
redundant components. Configuration can be
performed in a similar way as for standard systems.
Simple integration of redundant I/O No special knowledge is needed about redundant I/O
modules.
The communication links between the
system components are configured
transparent to the application.
With the HW Config or NetPro graphical user interface,
the configuration of the communication links is
performed transparent to the application.
2.6 Features for the commissioning and operation phases
Features for the commissioning and operation phases
The following table lists the features PCS 7 offers for the commissioning and operation phases.
The redundant components allows the continuation of the process of a component fails.
Operator control and monitoring of the process remains unaffected. In addition, the archiving
Basics of Fault Tolerance
2.6 Features for the commissioning and operation phases
Fault-tolerant Process Control Systems (V8.0)
20 Function Manual, 03/2012, A5E02779471-02