1OPC Unified Architecture
Pioneer of the 4th industrial (r)evolution

Industry

4.0
Multiplatform
Multivendor
SecureReliable2

Welcome to the OPC Foundation!
As the international standard forvertical and horizontal communication,
OPC UA provides semantic interoperability for cyber physical systems andplays a key role in the success of the
4th industrial (r)evolution.
Thomas J. Burke
President und Executive Director
OPC Foundation

OPC Unified Architecture (OPC UA) is the data exchange standard for safe, reliable, manufacturerand platform-independent industrial communication.
It enables data exchange between products fromdifferent manufacturers and across operating systems. The OPC UA standard is based on specifications that were developed in close cooperation between manufacturers, users, research institutes andconsortia, in order to enable safe information exchange in heterogeneous systems.
OPC has been very popular in the industrial automation and other market segments since 1995.
With the introduction of service-oriented architectures (SOA) in industrial automation systems in 2007,
OPC UA started to offer a scalable, platform-independent solution which combines the benefits ofweb services and integrated security with a consistent data model.

OPC UA is an IEC standard and therefore ideallysuited for cooperation with other organizations.
As a global non-profit organization, the OPC Foundation coordinates the further development of the
OPC standard in collaboration with users, manufacturers and researchers. Activities include:➞ Development and maintenance of specifications➞ Certification and compliance tests ofimplementations➞ Cooperation with other standards organizations
This brochure provides an overview of Industry 4.0
requirements and illustrates solutions, technical details and implementations based on OPC UA.
The broad approval among representatives from research, industry and associations indicates that OPC
UA is a key ingredient of data and information exchange standards for the Industry 4.0 project.

Regards,
Thomas J. Burke
President und Executive Director
OPC Foundation
thomas.burke@opcfoundation.org
www.opcfoundation.org

3Contents
4	OPC UA – pioneer of the
4th industrial (r)evolution
5	Industry 4.0 requirements –OPC UA solution	QUOTES
6 Research and education
8 Supplier and users from industry
10 Associations and organizations
12	OPC UA at a Glance
14	OPC UA technology in detailKarl-Heinz Deiretsbacher, Siemens AG and
Dr. Wolfgang Mahnke, ABB
22	Engineering:Interoperability by combining
AutomationML with OPC UA
Dr. Olaf Sauer, Fraunhofer Institute for Optronics,
System Technology and Image Exploitation(IOSB)
23	Scalability: OPC UA On chip level
Prof. Jasperneite, Fraunhofer Application CenterIndustrial Automation (IOSB-INA), Lemgo
24	Scalability: OPC UA in sensor
Alexandre Felt, AREVA GmbH27	Horizontal:
OPC UA enables M2M and IoT
Silvio Merz, Joint Water and Wastewater
Authority, Vogtland
28	Vertical: OPC UA fromproduction right into SAP
Roland Essmann, Elster GmbH
29	Vertical: OPC UA plus UMCM –The “USB connector” between
PLC and MES
Angelo Bindi, Central Control andInformation Systems Continental Teves30	Human-Machine Interaction:
OPC UA in a Browser
PD Dr.-Ing. Annerose Braune,
Dresden University of Technology
31	Smart Metering: consumption
information from the meter rightup to IT accounting systems
Carsten Lorenz, Elster GmbHOPC Foundation
32	Organization
33 Specification and Information
34	Code und certification for members
35	start-up assistance25	Identification: OPC UA in RFID
devicesDr. Jan Regtmeier, HARTING IT Software
Development GmbH & Co. KG
26	Integration: OPC UA Client and-Server in controller
Stefan Hoppe, BECKHOFF Automation

4

OPC UA – pioneer of the
4th industrial (r)evolution
Challenge
In order to maintain the competitiveness of Germany
as a production location it is necessary to meet thechallenges of increasing efficiency with ever shorterproduct cycles through more effective use of energy
and resources, of reducing time to market by producing more complex products faster with high innovative cycles, and of increasing flexibility throughindividualized mass production.
VisionThe 4th industrial revolution (Industry 4.0) is driven byadvanced information and communication technologies (ICT), which are becoming increasingly prevalent
in industrial automation. In distributed, intelligent systems physical, real systems and virtual, digital data
merge into cyber physical systems (CPS). TheseCPS are networked and form “smart” objects thatcan be assembled into “smart factories”. With increasing processing power and communication capacity, production units are able to organize themselves and become self-contained. They have all theinformation they need or can obtain it independently.
The systems are networked and autonomous, theyreconfigure and optimize themselves and are expandable (plug-and-produce) without engineeringintervention or manual installation. Virtual images arecarried throughout the production, product life timeand value creation chain within the produced goods
and always represent the current state of the actual
product. Such “smart” products are networked witheach other in the Internet of Things and respond tointernal and external events with learned behavior
patterns.
Requests
Considerable effort is required for implementing thevision of Industry 4.0 successfully, since demands
vary considerably. In order to reduce the complexity,
comprehensive modularization, wide-ranging standardization and consistent digitization is required.
These demands are not new. They are not revolutionary either, but the result of continous development.
This evolution is a long-standing process that started
a long time ago. Solutions for many of the requirements outlined below already exist. They are thefoundation of Industry 4.0.

Challenges for the implementation of Industry 4.0(several answers are possible)
Standardization
Securing the future of German manufacturing industry

Recommendations for
implementing the strategic
initiative INDUSTRIE 4.0
Final report of the Industrie 4.0 Working Group

147

Process  / work organization

129

Available products98

New business models

85

Security / know-how protection

78

Available skilled workers
April 201370

Research

64

Training / professional development

42

Legal framework

30
0Source: Forschungsunion, acatech 2013

Result of the Industry 4.0
platform survey:

20

40

60 80 100 120 140 160
No. of times mentioned

Source: “Recommendations for implementing the strategic initiative Industry 4.0”, Forschungsunion, acatech 2013

The members of BITKOM,
VDMA and ZVEI regarded
standardization as thebiggest challenge in theimplementation of Industry
4.0.

5

Industry 4.0 requirements – OPC UA solution
Industry 4.0 requirements

OPC UA solution

Independence of the communication
technology from manufacturer,
sector, operating system, programming language

The OPC Foundation is a vendor-independent non-profit organization. Membership is not required
for using the OPC UA technology or for developing OPC UA products. OPC is widely used in automation but is technologically sector-neutral. OPC UA runs on all operating systems – there are evenchip layer implementations without an operating system. OPC UA can be implemented in all languages – currently stacks in Ansi C/C++, .NET and Java are available.

Scalability for integrated networking
including the smallest sensors,
embedded devices and PLC
controllers, PCs, smartphones,
mainframes and cloud applications.
Horizontal and vertical communication across all layers.

OPC UA scales from 15 kB footprint (Fraunhofer Lemgo) through to single- and multi-core hardware
with a wide range of CPU architectures (Intel, ARM, PPC, etc.) OPC UA is used in embedded fielddevices such as RFID readers, protocol converters etc. and in virtually all controllers and SCADA/
HMI products as well as MES/ERP systems such as SAP and ITAC. Projects have already beensuccessfully realized in Amazon and Azure Cloud.

Safe transfer and authentication atuser and application level

OPC UA used x509 certificates, Kerberos or user/password for authentication of the application.
Signed and encrypted transfer, as well as a rights at data point level with audit functionality is alreadyavailable in the stack.

Service-orientated architecture(SOA), transport via establishedstandards such as TCP/IP for
exchanging live and historic data,
commands and events (event/callback)

OPC UA is independent of the transport method. Currently three protocol bindings are available:
optimized TCP-based binary protocol for high-performance applications and HTTP/HTTPS web
service with XML-coded messages. Further bindings are planned, e.g. XMPP and others. The
stacks guarantee consistent transport of all data and procedures arguments, events based on tokens.

Mapping of information content withany degree of complexity formodeling of virtual objects torepresent the actual products andtheir production steps.

OPC UA offers a fully networked (not only hierarchical but full-mashed network), object-oriented
concept for the namespace, including metadata for object description. Object structures can begenerated via referencing of the instances among each other and their types and a type model thatcan be extended through inheritance. Since servers carry their instance and type system, clients cannavigate through this network and obtain all the information they need, even for types that were
unknown to them before.

Unplanned, ad hoc communication
for plug-and-produce function withdescription of the access data andthe offered function (services) for
self-organized (also autonomous)
participation in “smart” networked
orchestration/combination ofcomponents

OPC UA defines different “discovery” mechanisms for notification of OPC UA-capable devices andtheir functions / features within subnets. Aggregation across subnets and intelligent, configurationless procedure (e.g. Zeroconf) are used to identify and address network participants.

Integration into engineering andsemantic extension

The OPC Foundation already collaborates successfully with other organizations (PLCopen, BACnet,
FDI, etc.) and is currently expanding its cooperation activities, e.g. MES-DACH, ISA95, MDIS (oil andgas industry), etc. A new cooperation initiative is with AutomationML, with the aim of optimizing interoperability between engineering tools.

Verifiability of conformity with thedefined standard

OPC UA is already an IEC standard (IEC 62541), and tools and test laboratories for testing andcertifying conformity are available. Additional test events (e.g. Plugfest) enhance the quality and ensure compatibility. Expanded tests are required for extensions/amendments (companion standards,
semantics).

6

QUOTES – RESEARCH AND EDUCATION»The paradigm of Industry 4.0 requires standards on
various levels, to enable an organization of modular plug&play capable production lines. OPC UA is
an important standard, helping us to establish communications between plant components in a vendor
independent and secure fashion. Because of the industry driven standardization process, we’re seeing
a high acceptance among industrial users of OPC
UA as a platform across all levels of the automation
pyramid. Furthermore, OPC UA’s information models
represents a basis for the realization of a semantic
inoperability.«Prof. Dr. Dr. Detlef Zühlke, Scientific Director
Innovative Factory Systems (IFS), DFKI

»A key component for the realization of the Industry
4.0 idea is an open and standardized communication platform. This is the only way to implement scenarios that require company-wide communication
across different levels. OPC UA provides a suitableand promising basis through its platform- and language-independent technology. The Institute of Automation and Information Systems (AIS) has alreadybeen using OPC UA for some years. Open architecture and support for a wide range of software andhardware are crucial benefits, particularly in a research environment. An example of this is the communication between a non-real-time-capable highlevel agent on a PC platform and a real-time-capable
low-level agent on a PLC. This enables optimum
distribution of computing time and speed.«
Prof. Dr.-Ing. Birgit Vogel-Heuser, Head of Institute of Automation andInformation Systems, Munich University of Technology (TUM)»One-off production, for example in the maritime industry or in special-purpose machine construction,requires human inclusion as an important component for the realization of Industry 4.0. Intelligent assistance systems and decision support through visualization of existential data are important componentsof flexible and highly automated production.
Both require contextualized integration of heterogeneous data from different sources (ERP, MES, PDA,ECMS, ambient sensors, etc.), as well as appropriate deployment via a graphic user interface and initiation of corresponding processes with multi-modal
interaction concepts. With its options for horizontal
and vertical integration, and particularly through support of semantics, OPC UA offers an ideal basis forsuch solutions.«
Prof. Dr. Bodo Urban, Head of the Rostock facility
Fraunhofer Institute for Computer Graphics Research IGD

7»OPC UA provides an ideal technology basis for Industry 4.0 which is all about intelligent networks between intelligent components. With Information
Modellings in it’s core, OPC UA supports the visionof Industry 4.0 with far more than just conveying
data. Information models convey real information in
the sense of know-how about structures, relationships and semantics – all of which is required for intelligent networking in the sense of Industry 4.0. In
addition, OPC UA is available in products alreadytoday. This is important because the so called revolution will take place as an evolution. And this evolution can be started right away.«
Prof. Dr.-Ing. Daniel Großmann, Computer Science and Data Processing,Technische Hochschule Ingolstadt»One of the basic ideas of Germany’s “Industrie4.0”-initiative is the interoperable communication between products, components, machines and IT-systems. This interoperability will only come to life with
open standards and, furthermore, already existing
open standards. That is why we prefer OPC UA toenable interoperability in a heterogeneous environment like a manufacturing shop floor. Especially because OPC UA supports the creation of information
models for the meaning of data, that means theirsemantics. In our current R&D-projects we use OPC
UA as the communication standard in the smart factory of the future – from the field device level to machines and from machines to the MES-level.«Dr. Olaf Sauer, Fraunhofer Institute for Optronics, System Technology andImage Exploitation (IOSB)

Quotes from research and education»OPC UA being a highly scalable technology enables
a seamless exchange of information between sensor, controller and ERP-Systems. In the next steps,
OPC UA is envisioned to be used to describe thesemantics of various services for a Smart Factory.«
Prof. Dr.-Ing. Jürgen Jasperneite, Head of Institute for Industrial
Information Technology (inIT), Ostwestfalen-Lippe University of Applied
Sciences and Fraunhofer Application Center Industrial Automation (IOSB-INA)»OPC UA has the potential to replace the numerous
Industrial Ethernet protocols by a direct link between
field devices and application, except for time-critical
data exchange.«
Prof. Dr. Hubert Kirrmann, Senior Principal Scientist,
ABB, Corporate Research

8

QUOTES – SUPPLIER AND USERS FROM INDUSTRY»OPC UA has the potential for an immediate crossvendor implementation of Industry 4.0 and the necessary internet based services.
The adoption of this open standard is an opportunity
for vendors and users. Proprietary solutions will notgenerate an adequate value.«
Dr.-Ing. Reinhold Achatz, Head of Corporate Function Technology,
Innovation & Sustainability, ThyssenKrupp AG

Acceptance in the industry»Industry 4.0 describes a change in the industry,caused by the merger of developments in factory automation, IT, Internet and social media. In this environment we see increasing intermeshing between
business management processes and automation,
which will ultimately lead to a simplified system landscape and measurable increase in productivity. In
the future, information such as test parameters, default values or machine settings will no longer require
redundant maintenance, but will only have to be defined once and can be exchanged directly with theautomation level. This reduces error sources andimproves the quality of the data and ultimately of the
products. SAP uses standards such as OPC UA,
which ensure simple, scalable and safe informationexchange with a wide range of factory systems. In
the long run, the complexity caused by the wide
range of shop floor systems can only be managed
based on standards.«
Veronika Schmid-Lutz, Product Owner Manufacturing, SAP AG»OPC UA turns out to be an ideal basis for the implementation of functions required by Industry 4.0, because the protocol is already available and integrated
in numerous devices, ranging from the sensor level
to MES and ERP systems. In addition, it is supportedby all automation suppliers. OPC UA also covers theinternal communication within the CPS and in somecases serves as fieldbus substitute or middleware
between the modules that interact within the CPS.«
Robert Wilmes, Phoenix Contact»OPC UA plays an important role in our Digital Enterprise Platform approach on the evolutionary route to
the Industry 4.0 vision.«
Prof. Dr. Dieter Wegener, Siemens Industry Sector, VP Advanced
Technologies & Standards

9»As a founder member of the OPC Foundation,
Siemens is keen to generate added value for its
customers – through promotion of automation andfurther development and interoperability of the technologies from different system providers. OPC standards are used in many of our innovations, such as
the Sinema Server network management solution,
the Simatic HMI or the flexible, modular Simocode
pro motor management system. OPC UA is an implementation that we regard as particularly relevant.
This is why we have always been very active in thisarea right from the start and are among the firstcompanies whose products are certified.«»For modular and scalable production facilities in the
future we expect significantly reduced efforts to connect those machines to superior systems like MES
and ERP by using OPC UA. The big advantage for us
is that a non-proprietary communication standard
has been created. To be able to really get those benefits it is essential for us that hardware manufacturers
are going to implement OPC UA servers directly on
their embedded systems.«
Steffen Schmidt, Head of Control Technology Design, Festo

Thomas Hahn, Siemens AG, OPC board member

Pioneers in automation»Industry 4.0 links the world of automation with the IT
and Internet world and will enable the resulting synergies to be leveraged. Networking means communication, communication requires languages and associated functions and services. OPC UA offers avery powerful and adaptable standard basis that is
accepted worldwide.«Hans Beckhoff, Managing Director, Beckhoff Automation GmbH»The merger of automation technology and information technologies requires two key elements. Firstly– an intelligent, networked system that can makerule-based decisions and save data, i.e. a Manufacturing Execution System (MES) – and, perhaps evenmore important, secondly – a communication layerthat is fast, platform-independent, scalable and safe
and can be integrated horizontally and vertically,
from the device level right into ERP systems, i.e.
OPC UA. We then have an Industry 4.0-capable system or a so-called cyber-physical system (CPS) thatis independent of the location of the stored data.«
Angelo Bindi, Senior Manager Central Control and Information Systems
Continental Teves – Gründunsgmitglied und Vorstand MES DACH10QUOTES – ASSOCIATIONS AND ORGANIZATIONS»Industry 4.0 means vertical integration along all levels of the value-chain and horizontal integration means integration into value-added networks. This is
why the realisation of Industry 4.0 will crucially depend on interfaces. In this respect OPC UA provides
numerous advantages, not least being an established and widely accepted standard. This is an indispensable feature to include as many stakeholders as
possible, particularily smaller and medium-sizedenterprises. Being a uniform interface providing realtime and security capabilities as well as interfaces forsemantic applications, OPC UA is a vendor-independent communication solution, which is suitable forIndustry 4.0 applications in a natural way.«»Standardization is an effective lever for innovations
in many economic sectors, including the applicationof Industry 4.0 in manufacturing companies. The
new type of added-value networks with dynamic
business models across company and industry
boundaries and the vertical integration within companies encompassing the installed systems requires
a wide range of interfaces and different strategy forstandardization. This was confirmed by a survey relating to the Industry 4.0 platform. The members of
BITKOM, VDMA and ZVEI regarded standardization
as the biggest challenge in the implementation of Industry 4.0. Organizations such as OPC Europe playa key role.«

Dr. Bernhard Diegner, Head of research, vocational training,production engineering at ZVEI

Wolfgang Dorst, Head of Industry 4.0 at BITKOM,
member of Industry 4.0 platform project management

Recommendations by associations»To reach the goals of Industry 4.0, solutions are necessary, to realise secure and efficient communication between machines and plants by the useof information technology. All available solutions,
OPC UA, too, offer real possibilities, to solve thesetasks and to realise the ideas of Industry 4.0.«
Peter Früauf, VDMA, Electrical Automation

11

IT Solutions.
Simplified.

»We use the term Industry 4.0 to describe the transition from automated to decentrally networked, selfcontrolling production environments in which machines communicate with machines, workpieces
and components. This calls for the MES to recordand calculate the processed data from all of the sensors and actuators in real-time. The MES plays a pivotal role in Industry 4.0 manufacturing scenarios andforms the “nucleus” of the smart factory. MES-facility
integration is largely dependent on the ability to exchange data between all of the systems via open interface standards like OPC UA. This protocol offers
advantages because it is supported by many automation vendors and can be used regardless of theplatform. Implementing this standard is a task for the
manufacturing industry, a process which we support
and offer advice on based on our in-depth knowhow on Industry 4.0.«»Communication is not about data. Communication
is about information and access to that in aneasy and secure way. This is what the cooperation
PLCopen and OPC Foundation is all about. OPC UA
technology creates the possibility for a transparent
communication independent of the network, whichis the foundation for a new communication age inindustrial control.«Eelco van der Wal, Managing Director PLCopen

Thomas Ahlers, Member of the Executive Committee of Freudenberg IT,
and Chairman of the BITKOM Work Group Industry 4.0 Interoperability»BACnet and OPC UA are already cooperating in
the exploration of new opportunities for integration
between industrial and building automation: Energy
data are semantically defined through BACnet andcan conveniently and interoperably be made available to enterprise systems via OPC UA: An ideal
standardization from sensor right up to IT billing systems.«»The complexity of industrial systems is continuously
increasing. To manage this complexity within design
and application methods and technologies are required enabling modularity and consequent structuring. The OPC technology and its newest representative OPC UA have been proven to be successfully
applicable in this field. It is wide spread applied andcan be regarded as entry point for the combinationof engineering and application as intended in the Industry 4.0 approach.«Prof. Dr.- Ing. habil. Arndt Lüder, Otto-v.-Guericke University Magdeburg,
Fakulty Mechanical Engineering, AutomationML e.V. Board of Directors

Frank Schubert, member of the BACnet Interest Group Europe
advisory board

12

OPC UA at a glance

OPC UA at a glance –secure, reliable and platform-independentexchange of information

SECURE, RELIABLE AND PLATFORMINDEPENDENT EXCHANGE OF INFORMATIONOPC UA is the new technology generation from the
OPC Foundation for the secure, reliable and vendorindependent transport of raw data and preprocessed information from the sensor and field levelup to the control system and into the production
planning systems.
With OPC UA every type of information is available
anytime and anywhere for every authorized use andto every authorized person.
PLATFORM AND VENDOR-INDEPENDENTOPC UA is independent of the vendor or system
supplier that produces or supplies the respective application. The communication is independent of the
programming language in which the respective software was programmed and it is independent of theoperating system on which the application runs. It isan open standard without any dependence on,or bind to proprietary technologies or individual
vendors.
STANDARDIZED COMMUNICATION VIAINTERNET & FIREWALLSOPC UA extends the preceding OPC industry standard by several important functions such as platform
independence, scalability, high availability and Internet capability. OPC UA is no longer based on Microsoft’s DCOM technology; it has been reconceived on
the basis of service-oriented architecture (SOA).
OPC UA is thus very simple to adapt. Today OPC UA
already connects the enterprise level right down tothe embedded systems of the automation components – independent of Microsoft, UNIX or any otheroperating system. OPC UA uses a TCP based, optimized, binary protocol for data exchange over a port
4840 registered with IANA. Web service and HTTP
are also optionally supported. It is sufficient to open

up a single port in the firewall. The integrated encryption mechanisms ensure secure communication overthe Internet.
SERVICE-ORIENTED ARCHITECTURE
OPC UA defines generic services and in doing so
follows the design paradigm of service-oriented architecture (SOA), with which a service provider
receives requests, processes them and sends theresults back with the response.
In contrast to classic Web services that describe
their services over a WSDL and can thus be different
with each service provider, generic services are already defined with OPC UA.
A WSDL is thus not required, because the services
are standardized. As a result they are compatible
and interoperable, without the caller needing to haveany special knowledge about the structure or behavior of a special service. OPC UA defines various
groups of services for different functions (reading/writing/signaling/execution, navigation/searching, connection/session/security). The flexibility results via the OPC UA information model. Building ona basic model, any desired complex, object-oriented
extensions can be made without impairing the interoperability in the process.
PROTECTION AGAINSTUNAUTHORIZED ACCESSOPC UA technology uses proven security concepts
that offer protection against unauthorized access,against sabotage and the modification of processdata and against careless operation. The OPC UA
security concepts contain user and application
authentication, the signing of messages and theencryption of the transmitted data itself. OPC UA
security is based on recognized standards that arealso used for secure communication in the Internet,
such as SSL, TLS and AES. The safety mechanisms

13

Uniform OPC UA object

OPC UA
ObjectAttribute
Service Set(Data Access,Historical
Data Access)

Variables
_____
_____
_____

Methods_____( )_____( )_____( )EventsN
NN

are part of the standard and are obligatory for vendors. The user may combine the various security
functions according to his case of use; thus scalable
security results in relation to the specific application.
ACCESSIBILITY AND RELIABILITYOPC UA defines a robust architecture with reliablecommunication mechanisms, configurable timeouts
and automatic error detection.
The error elimination mechanisms automatically restore the communication connection between the
OPC UA client and the OPC UA server without lossof data. OPC UA offers redundancy functions thatare integrable in both client and server applications
and thus enable the implementation of high-availability systems with maximum reliability.
SIMPLIFICATION BY STANDARDIZATIONOPC UA defines an integrated address space and an
information model in which process data, alarms andhistorical data can be represented together withfunction calls. OPC UA combines all classic OPC
functionalities and permits the description of complex procedures and systems in uniform objectoriented components. Information consumers that
only support the basic rules can process the data
even without knowledge of the interrelationships ofthe complex structures of a server.

MethodService Set(Programs)

Subscription
Service Set(Alarms &Conditions)

AREAS OF APPLICATIONThe universal applicability of OPC UA technology enables the implementation of entirely new vertical integration concepts. The information is transported securely and reliably from the production level into the
ERP system by cascading OPC UA components.
Embedded OPC UA servers at field device level andintegrated OPC UA clients in ERP systems at enterprise level are directly connected with one another.
The respective OPC UA components can be geographically distributed and separated from one another by firewalls. OPC UA enables other standardization organisations to use the OPC UA services asa transport mechanism for their own information
models. The OPC Foundation already cooperates
today with many different groups from different industries, including PLCopen, BACnet, ISA and FDI.
Additional specifications are compiled that containcommon, semantic definitions of information
models.

OPC UA technology in detail

14

OPC UA technology in detailIndustry 4.0 communication is not only based onpure data, but on the exchange of semantic information. In addition, transmission integrity is a key factor.
These tasks are essential aspects of the OPC Unified
Architecture. OPC UA contains a comprehensive description language and the communication services
required for information models and is therefore universally usable.
Karl-Heinz Deiretsbacher,
Industry Automation Division
Siemens AG
Director of the OPC UA TechnicalAdvisory Board

Introduction
The trend in automation is towards inclusion of communication data semantics in the standardization.
Standards such as ISA 88 (also IEC 61512, batchprocessing), ISA 95 (also IEC 62264, MES layer)or the Common Information Model (CIM) withIEC 61970 for energy management and IEC 61968
for energy distribution define the semantics of thedata in domains addressed by them. Initially thistakes place independent of the data transfer specification.
OPC UA – also published as IEC 62541 – enables
exchange of information models of any complexity –both instances and types (metadata). It thus complements the standards referred to above and enables
interoperability at the semantic level.

Dr. Wolfgang Mahnke,
Software Architect R&D Fieldbus
ABB Automation GmbH

Design objectives
OPC UA was designed to support a wide range ofsystems, ranging from PLC in production to enterprise servers. These systems are characterized bytheir diversity in terms of size, performance, platforms and functional capabilities.
In order to meet these objectives, the following basic
functionalities were specified for OPC UA:➞T ransport – for the data exchange mechanisms
between OPC UA applications. Different transport
protocols exist for different requirements (optimized for speed and throughput = UA TCP withUA Binary; firewall-friendly = HTTP + Soap).
➞M eta model – specifies the rules and basic components for publishing an information model via
OPC UA. It also includes various basic nodes andbasic types.
➞S ervices – they constitute the interface between aserver as information provider and clients as usersof this information.
Information models follow a layered approach. Eachhigh-order type is based on certain basic rules. In
this way clients that only know and implement thebasic rules can nevertheless process complex information models.
Although they don’t understand the deeper relationships, they can navigate through the address spaceand read or write data variables.

BinaryVendor Specific Extensions

AC

Web services

UA BinaryCollaboration Models

DA

HybridHAPrg

UA XMLWS Secure
Conversation

UA Secure
Conversation
UA TCP

SOAP

Base Services
HTTPS
Transport

TCP / IP

Meta Model
4840

OPC UA layer model

HTTP

443

OPC UA transport profiles

443

80

15

Integrated address space model
The object model enables production data, alarms,
events and historic data to be integrated in a single
OPC UA server. This allows, for example to represent
a temperature measuring device as an object with its
temperature value, alarm parameters and corresponding alarm limits.
OPC UA integrates and standardizes the different
address spaces and the services, so that OPC UA
applications only require a single interface for navigation.

The OPC UA address space is structured hierarchically, to foster the interoperability of clients and servers. The top levels are standardized for all servers. All
nodes in the address space can be reached via thehierarchy. They can have additional referencesamong each other, so that the address space forms
a cohesive network of nodes.
The OPC UA address space not only contains instances (instance space), but also the instance types(type space).

Root

Field Bus

Sensor Bus

Areas“Located In“reference

Pressure
Xmitter

Valve

Temp
Xmitter

Area 1

Area 2Hi Limit

Current Value

Hi Alarm

Consistent address space

Lo Limit
Lo Alarm

Area 3

16

OPC UA technology in detail

Integrated services
OPC UA defines the services required to navigate
through the namespace, read or write variables, or
subscribing for data modifications and events.
The OPC UA services are organized in logical groupings, so-called service sets. Service request and response are transmitted through exchange of messages between clients and servers.
OPC UA messages are exchanged either via a OPCspecific binary protocol on TCP/IP or as a web service. Applications will usually provide both protocol
types, so that the system operator can choose thebest option.
OPC UA provides a total of 9 basic service sets. The
individual sets are briefly described below. Profiles
allow specifying a subset of all services which a server supports. Profiles are not discussed in detail here.
➞	SecureChannel service set	This set includes services to determine the security configuration of a server and establish a communication channel in which the confidentiality
and completeness (integrity) of the exchanged
messages is guaranteed. These services are not
implemented directly in the OPC UA application
but are provided by the communication stackused.
➞	Session service set	This service set defines services used to establish
an application-layer connection (a session) on behalf of a specific user.

➞	NodeManagement service set
	These services provide an interface for the configuration of servers. It allows clients to add, modify, and delete nodes in the address space.
➞	View service set
	The view service set allows clients to discovernodes by browsing. Browsing allows clients tonavigate up and down the hierarchy, or to follow
references between nodes. This enables the client to explore the structure of the address space.
➞	Attribute service set
	The attribute service set is used to read and write
attribute values. Attributes are primitive characteristics of nodes that are defined by OPC UA.
➞	Method service set
	Methods represent the function calls of objects.
They are invoked and return after completion.
The method service set defines the means to invoke methods.
➞	MonitoredItem service set	This service can be used to determine which attributes from the address space should be monitored for changes by a client, or which events theclient is interested in.
➞	Subscription service set	Can be used to generate, modify or delete messages for MonitoredItems.
➞	Query service set
	These services enable the client to select nodes
from the address space based on certain filter criteria.

17Platform-independence
Unlike “Classic OPC”, which is based on DCOM
technology and is therefore inevitably linked to the
Windows platform and the languages supported
there, OPC UA was designed for application on arbitrary platforms using arbitrary program languages.

Tool orLanguage
Dependent(e.g. .NET)

API
Proxy /
Stubs
Services
Binding
Abstract UA Model
Specification

Services are independent of the model➞ 	At the lowest level are the abstract OPC UA
model and the services, including the whole address space model, different object and variable
structures, alarms and more.
➞ 	The next level (Services Binding) is used to
specify how the services are to be mapped to certain protocols. Currently mappings for TCP (UATCP) and for HTTP (OPC UA WebServices) areavailable. In the future – once new technologies
become established – further mappings can be
specified without having to change the OPC UA
model and the services. The mappings are entirely based on standardized basic protocols,
which already exist on all known platforms.
➞ 	The following levels are realizations for dedicated platforms and languages. The OPC Foundation itself offers three such realizations, namely
for Java, .NET and AnsiC/C++.
	The last option contains a platform adaptation
layer.

Performance
The OPC UA services can be mapped to different
technologies. Currently there are essentially two
mappings: UA-TCP and HTTPS. The use of UA-TCP
on top of advanced Ethernet technologies ensureshigh performance.
The services themselves are also designed for highdata throughput. An individual read call can accessthousands of values, for example. Subscriptions services enable notification when values are changed
and exceed configured thresholds

Information models with OPC UA
The OPC UA meta model➞ Important: The OPC UA model describes
how clients access information on the server. It does not specify how this information
should be organized on the server. It could
be stored in a subordinate device or a database, for example.

The OPC UA object model defines a set of standardized node types, which can be used to represent
objects in the address space. This model represents
objects with their variables (data/properties), methods, events and their relationships with other objects.
The node properties are described through attributes
defined by OPC UA. Attributes are the only elementsof a server that have data values. The data types of
the attributes can be simple or complex.
OPC UA enables modeling of any object and variabletypes and the relationships between them. The semantics is indicated by the server in the address
space and can be picked up by clients (during navigation). Type definitions can be standardized or vendor-specific. Each type is identified by the organization that is responsible for its definition.

18

OPC UA technology in detail

Generic OPC UA information models
Models for generally valid information (e.g. alarms or
automation data) are already specified by OPC UA.
Other information models with further specializationof the general definitions are derived from this. Clients that are programmed against the general models are therefore also able to process the specialized
models to a certain extent.

2. Alarms and Conditions (AC)This information model defines how states (dialogs,
alarms) are handled. A change of state triggers an
event. Clients can register for such events and selectwhich of the available associated values they want toreceive as part of the event report (e.g. message
text, acknowledgment behavior).
3. Historical Access (HA)
HA enables the client to access historic variable values and events. It can read, write or modify these
data. The data can be located in a database, an archive or another storage system. A wide range ofaggregate functions enable preprocessing in theserver.

1. Data Access (DA)
Data access, DA in short, describes the modeling of
automation data. It includes the definition of analog
and discrete variables, engineering units and quality
codes. Data sources are sensors, controllers, position encoders etc. They can be connected either via
I/Os located directly at the device or via serial connections and fieldbuses on remote devices.

4. Programs
A “program” represented a complex task, such as
operation and handling of batch processes. Each
program is represented by a state machine. Statetransitions trigger messages to the client.

Boiler 1
Pipe1001

FC1001
FT1001

Measurement

SignalDataItem

FlowToControlOut

Valve1001

Signal
Setpoint

DataItem

LC1001

Drum1001
LI1001
FlowToMeasurement

SignalDataItem

SignalExecutes

ControlOut

Pipe1002
FT1002SignalExecutes

Setpoint
CC1001

DataItem

SignalSignalInput1
Executes
Input2
Input3ControlOut

UA modeling of a boiler as an example

ControlModule

19

Technology-specificinformation models
Standardization committees dealing with the control/
automation technology prepare technology-specificinformation models. Examples are IEC61804 (EDDL),ISA SP 103 (field device tool), ISA-S88, ISA-S95 and
IEC-TC57-CIM. These specifications are important,since they standardize the descriptions of units, relations and workflows in certain fields of knowledge.
The OPC Foundation was keen to collaborate withother organizations in the development of the newstandard right from the start. Rules for mapping theinformation models of these organizations to OPC
UA (companion standards) are specified in joint
working groups.

The following companion standards
currently exist or are in preparation:➞O PC UA for Devices(IEC 62541-100)➞O PC UA for Analyser Devices➞O PC UA for Field Device Integration➞O PC UA for Programmable Controllers
based on IEC61131-3➞O PC UA for Enterprise and Control
Systems based on ISA 95➞O PC UA for Machine Tool Connectivity(MTConnect)

Source: Extract from the 4th annual colloquium “Communication in Automation” (KommA 2013), ISBN: 978-3-944722-00-9

20

OPC UA technology in detailSecurity Model
GeneralSecurity is a fundamental requirement for OPC UA
and was therefore integrated in the architecture. The
mechanisms (comparable to the Secure Channel
concept of W3C) are based on a detailed analysis of
the threats.
OPC UA security deals with the authentication of clients and servers, the integrity and confidentiality ofthe exchanged messages and the verifiability offunctional profiles.
OPC UA security complements the security infrastructure provided by most web-enabled platforms.
It is based on the architecture shown in the diagram
below. The three levels are User Security, Application
Security and Transport Security.
The OPC UA user level security mechanisms are executed once when a session is set up. The clienttransmits an encrypted security token, which identifies the user, to the server. The server authenticatesthe user based on the token and then authorizes theaccess to objects in the server. The OPC UA specification does not define authorization mechanisms
such as access control lists. They are applicationand/or system-specific.

OPC UA application level security is also part of thesession setup and includes the exchange of digitally
signed certificates. Instance certificates identify theconcrete installation. Software certificates identify
the client and server software and the implemented
OPC UA profiles. They describe capabilities of theserver, such as support for a specific information
model.
Transport level security can be used to provide integrity by signing the messages and confidentiality by
encrypting the messages. This prevents disclosureof the exchanged information and ensures that themessages have not been manipulated.
The OPC UA security mechanisms are realized aspart of the OPC UA stacks, i.e. they are included in asoftware package provided by the OPC Foundation
and are ready to be used by client and server.

Client platform
User
Security

Client application

AP
Security

OPC UA Comms

Transport
Security

Platform Comms

Server platform
User security token

Authentication ofServer application

OPC UA Commsclient, server, messages

Scalable security concept

Signing and Encryption

Platform Comms

Authorization andaccess control

Serverobjects

21

Scalable security
Security mechanisms come at a price and have an
impact on performance. Security should therefore
only be applied in situations where it is actually required. This decision should not be made by the developer / product manager, but the system operator(system administrator).
The OPC UA security mechanisms are scalable.
OPC UA servers provide so-called end points representing different security levels. There is also an end
point without security (“NoSecurity” profile). The system administrator can deactivate certain end points(e.g. the end point with the NoSecurity profile). During operation, the operator of a OPC UA client canselect the end point suitable for the respective action
when the connection is established.
OPC UA clients themselves can ensure that they always select end points with security for access tosensitive data.

Secure Channel
The SecureChannel is used to define the SecurityMode and the SecurityPolicy. The SecurityMode describes how the messages are encrypted.
Three options are available, as defined by OPC UA:“None”, “Sign” and “SignAndEncrypt”. The SecurityPolicy defines algorithms for encrypting the messages.
For setup, the client needs the public key of the server instance certificate. The client then transfers its
own instance certificate, based on which the server
decides whether it trusts the client.

Industry 4.0: Outlook
OPC UA is a mature standard, which meets therequirements of Industry 4.0 regarding semanticinteroperability. OPC UA provides the protocol
and services (the “How”) for publishing comprehensive information models (the “What”) and exchanging complex data between applications
that were developed independently.

Although various important information models
already exist, there is still a need for action:➞H ow for example, does a temperature sensor
or a value control unit identify itself?
➞W hich objects, methods, variables and events
define the interface for configuration, initialization, diagnostics and runtime?

22

OPC UA Solutions

Engineering: Interoperability by combining AutomationML with OPC UA

Requirements for the factory of the future
Dr. Olaf Sauer, Fraunhofer Institute for Optronics, System Technology and Image Exploitation (IOSB),
Initiator of common working group “AutomationML and OPC UA”

The factory of the future has to be capable of producing customer-specific products in ever new variants, for instance, ensuring short product life cycles,
quick delivery times, zero-defect production and resource-efficient manufacturing. Industrie 4.0 is a
strategic framework program focusing on the increasing significance of information in the manufacturing industry. There is a wide range of individual
technologies in place, which now have to be consolidated for industrial use. One of the major requirements for the Industrie 4.0 ICT architecture is theability to adapt to changes – either in the case thatnew equipment or production processes are added
to the system or in the case that existing production
systems are changed because a new, additional
product variant is to be manufactured, for instance.
This capability is called adaptive ICT. The basic idea
behind adaptivity is the use of self-describing methods relating to functionality, identification, self-establishment of communication and standardized dataexchange in case new components, machinery or
equipment are added to a production system or incase there are changes in production that affect thesoftware.

Automation MLTM and OPC UA for
Industrie 4.0
Self-configuration can be achieved by using Automation ML to describe the capabilities of components and machines and OPC UA to enable them tocommunicate with each other. The cooperation between OPC Foundation and AutomationML e. V.
aims at combining the two technologies to form
methods and tools for information and software architectures allowing for consistent, reliable availability
and communication of data in the case of modifications to the factory. To this end, features and capabilities are stored as AutomationML objects within
the very components. Consequently, they are readily
available to the control system as OPC UA information models at the time of physical integration. Component suppliers identify the information required forthis purpose in advance so it is included in the components themselves. The physical and informationrelated integration results in time savings of approximately 20 % in the case of initial start-ups,
maintenance activities and changes in production.
Even greater potentials can be opened up if data required for the configuration of an MES is extracted
from the engineering systems on which they arebased and stored directly in OPC UA information
models as AutomationML objects.

23

Scalability: OPC UA in chip level»OPC UA on chip level as an enabler for
Industry 4.0«
Prof. Dr.-Ing. Jürgen Jasperneite, Head of Institute for Industrial Information Technology (inIT), Ostwestfalen-Lippe
University of Applied Sciences and Fraunhofer Application Center Industrial Automation (IOSB-INA)

Industry 4.0 describes the vision of intelligent technical systems by means of functions such as self-optimization, self-configuration and self-diagnosis in future adaptive and predictive systems. Such systems
interact with their environment and can adapt to it bylearning. This can lead to new solutions that arecharacterized by versatility, resource efficiency anduser-friendliness. In addition to the cognitive information processing that goes well beyond today‘s usualreflexive information processing in automation technologies, the intelligent networking is of central importance.

In todays’ automation technique diverse communication techniques (e.g.: real-time Ethernet, WLAN),
which are optimized for the use case, have been established, but the vertical flow of information from thesensor level up to the Internet is still often constraint
by technology differences. With the help of OPC UA
this can be solved now. In 2012, the Fraunhofer Application Center IOSB INA, together with inIT (Institute Industrial IT) of the OWL University, has demonstrated as part of an internet of things related EU
project, that OPC UA is scalable in a level that an
OPC UA server with only 15 Kbytes of RAM and10kbyte ROM can be implemented directly on achip. The „Nano Embedded Device Server profile“ ofthe OPC Foundation has been used for this purpose.
The protocol stack is implemented in ANSI C andconsists of about 2000 lines of code and it uses abasic TCP/IP functionality. Now using off the shelf
OPC UA clients, it is possible to directly communicate with field devices. Also to compress the information an aggregation of servers can be realized. An
important part of this concept is that for the timecritical machine-oriented data transmission, the OPC
UA communication can take place in parallel to thereal-time communication. In a next step, the OPC UA
strong information modelling and interoperability related functionalities should be used towards achieving plug- and-play of field devices. For this a semantic interoperability is necessary, which enables thedescription, localization and dynamic orchestrationof services. This reduces the reconstruction andcommissioning of automated systems significantly
and thereby increases the mutability of manufacturing companies.

24

OPC UA Solutions

Scalability: OPC UA in sensor»The integration of OPC UA into our measuring
instruments provides our customers withcomprehensive, secured communication«
Alexandre Felt, Project Manager at AREVA GmbH

Scalability: AREVA benefits
from sensors with integrated
OPC UA protocol
Comprehensive, end-to-end networking across alllevels represents a challenge to Industry 4.0. As an
evolutionary step towards realization of the 4th industrial revolution, companies can already take adecisive step in the right direction with Embedded
OPC UA. In cooperation with its partner Matrikon
OPC, the company AREVA recognized early on thepotential of OPC UA in sensors and started integrating them into monitoring instruments (SIPLUG®) for
mountings and their associated electric drives. The
solution is used in the nuclear industry for monitoring
critical systems in remote environments, without
negatively affecting the availability of the system.
Before this, SIPLUG® utilized a proprietary data exchange protocol, just like most of the applications in
the nuclear energy sector – this meant however that
integration into existing facility infrastructures wasdifficult, and the outlay for various aspects, such asdata buffering or data analyses, was always linked
with extra costs.
Benefits of embedded OPC UA
From an end-user perspective, the native OPC UA
connectivity enables direct embedding of AREVA
products into the infrastructure, without the need forany additional components: The solution allows thereporting and trend monitoring system of AREVA toaccess the SIPLUG® data directly. This means thatthe need for additional drivers and infrastructures
can be dispensed with completely. What’s more, additional values, such as pressure and temperatureWith AREVA, OPC UA can be used to provide access to
SIPLUG® data within the upper levels of a company via an
open, international standard (IEC62541) – the challenge of“end-to-end data availability“ has therefore been solved with
OPC UA.

values available at the factory level, can be utilizedeasily in order to improve the precision of the data
evaluation.
With AREVA, OPC UA can be used to provide access to SIPLUG® data within the upper levels of acompany via an open, international standard(IEC62541) – the challenge of “end-to-end data
availability“ has therefore been solved with OPC UA.
Smallest dimensions –integrated security
In addition to the reliability of the data, integrated security was also an important aspect for the utilizationof OPC UA. The minimal memory requirements,
which start at 240kB flash and 35kB RAM, can be
integrated into the smallest devices of AREVA.

25

Identification: OPC UA in RFID devices»RFID & OPC UA as building blocks
for Industry 4.0«
Dr. Jan Regtmeier, HARTING IT Software Development GmbH & Co. KG

The vision of the industry 4.0 aims at seamless communication between real objects and different computer systems. One goal is that a product controls its
own production process.
The first hurdle, however, occurs early on: how doesa software system identify a real object, for example,
a tool or a concrete part? Here RFID helps. By implementing a transponder, an object obtains an identity.
And in addition, the object receives a memory, the socalled user memory, and if needed, sensing elements in form of sensors e.g., to measure the ambient temperature.
Thus, right at the start of a production process, thefinal product specs can be defined and stored on theobject. Then, the product finds its own way throughthe various production steps. At each step in thisprocess, different systems require the RFID data of
the product. This can be a PLC, but in other cases a
MES or ERP system is possible as well. But currently all systems speak different languages. For example
PLC: Profinet, Ethernet / IP, EtherCAT, CC-Link , etc.
This drives the integration efforts concerning timeand money for the customer. Here, OPC UA allows
that everyone understands each other.
The most important task for the RFID reader manufacturers so far has not been addressed, and is mygoal: „The big RFID manufacturers need to agree on
semantics mapped in OPC UA.“

OPC UA Solutions

26

Integration: OPC UA Client and -Server in controller»OPC UA: Via semantic information modellingfrom controller into cloud«Stefan Hoppe, Beckhoff Automation, Produkt Manager TwinCAT
Chairman der gemeinsamen Arbeitsgruppe PLCopen & OPC Foundation, President OPC Foundation Europe

The interaction between IT and the world of automation is certainly not revolutionary, but is based on thelong-established model of the automation pyramid:
The upper level initiates a data communication (as aclient) with the level below, which responds (as server) cyclically or event-driven: A visualization, for example, can request status data from the PLC ortransfer new production recipes to the PLC.
With Industry 4.0 this strictly separation of the levels
and the top-down approach of the information flow
will start to soften and mix: In an intelligent network
each device or service can autonomously initiate acommunication with other services.

Storage

Cloud

OPC UA server
Historic data

ERP
MES

SCADA/HMI

PLCs

Factory Floor

PLC controller initiates horizontal
and vertical communication
In collaboration with the OPC Foundation, the PLCopen (association of IEC6-1131-3-based controller
manufacturers) has defined corresponding OPC UA
client function blocks. In this way the controller canplay the active, leading role, in addition or as an alternative to the usual distribution of roles. The PLC canthus horizontally exchange complex data structureswith other controllers or vertically call up methods inan OPC UA server in an MES/ERP system, e.g. toretrieve new production orders or write data to thecloud. This enables the production line to become
active autonomously – in combination with integrated OPC UA security a key step towards Industry 4.0.
Semantic interoperability
A mapping of the IEC61131-3 software model to the
OPC UA server address space is defined through thestandardization of the two organizations: The advantage for users is that a PLC program that is executedon different controllers from different manufacturers,
externally results in semantically identical access for
OPC UA clients, irrespective of their function: Thedata structures are always identical and consistent.
The system engineering is simplified significantly.
The sector-specific standardization of the semantics
is already used by other organizations and is the actual challenge of Industry 4.0.

27

Horizontal: OPC UA enables M2M and IoT»Intelligent water management –M2M interaction based on OPC UA«
Silvio Merz, Divisional Manager, Electrical/Process Technology
Joint Water and Wastewater Authority, Vogtland

Level
reached!

Closeduser group

OK, I’mswitching off!

Drinking
water quality?

Closeduser group

All OK!

Closeduser group

If we regard some of the basic concepts of Industry
4.0, such as platform and vendor-independent communication, data security, standardization, decentralized intelligence and engineering, then a technology for M2M (Machine-to-Machine) or IoT (Internet ofThings) applications is already available in OPC UA.
OPC UA is used for direct M2M communication between plants for the intelligent networking of decentralized, independently acting, very small embedded
controllers, i.e. around 300 potable water plants and
300 wastewater plants (pumping plants, water
works, elevated reservoirs, etc.) distributed overabout 1,400 km²:
Real objects (e.g. a pump) were modeled in the
IEC61131-3 PLC as complex objects with interactive
possibilities; thanks to the OPC UA server integrated
in the controller these objects are automatically available to the outside world as complex data structures
for semantic interoperability.
The result is a decentralized intelligence that makes
decisions independently and transmits information to
its neighbors or queries statuses and process values
for its own process in order to ensure a trouble-freeprocess cycle.
With the standardized PLCopen function blocks thedevices independently initiate communication fromthe PLC to other process devices as OPC UA
clients, whilst at the same time being able to respondto their requests or to requests from higher-levelsystems (SCADA, MES, ERP) as OPC UA servers.
The devices are connected by wireless router: aphysical interruption of the connection does not leadto a loss of information, since information is automatically buffered in the OPC UA server for a timeand can be retrieved as soon as the connection has
been restored – a very important property in which agreat deal of proprietary engineering effort was invested beforehand. The authentication, signing andencryption safety mechanisms integrated in OPC UA
were used in addition to a closed mobile radio groupto ensure the integrity of these partly sensitive data.
The vendor-independent interoperability standard
OPC UA opens up the possibility for us as end users
to subordinate the selection of a target platform forthe demanded technology in order to avoid the useof proprietary products or products that don‘t meetthe requirements.
The replacement of a proprietary solution by a combined OPC UA client/server solution, for example,
provided us with a saving on the initial licensing costsof more than 90 % per device.

OPC UA Solutions

28

Vertical: OPC UA from production right into SAP

Seamless MES integration of systems with
OPC UA simplifies shop floor programming
Roland Essmann, Elster GmbH, project manager for Manufacturing Execution System (MES)SAP ERP

The product itself determines the way it should be
produced. Ideally this enables flexible production
without the need for manual setting up. Elster havealready implemented the vision of Industry 4.0 in firstpilot lines.
A key factor is the seamless integration between
shop floor, MES and ERP based on OPC UA. At
each step the product is identified through its unique
shopfloor controlnumber (SFC). OPC UA enables theplant control system to be coupled directly with the
MES system, so that flexible procedures and individual quality checks can be realized in one-pieceflow mode. Without any additional effort, PLC variables are published as OPC tags, and simply
mapped to the MES interface. This enables fast andconsistent data transfer, even for complex struc-tures. The MES system receives the QM specifications via orders from the ERP and reports the finished products back to the ERP. Vertical integrationis therefore not a one-way street, but a closed loop.
In future, intelligent products with their own data
storage will offer the prospect of exchanging much
more than just a shopfloor controlnumber with theplant. It is conceivable to load work schedules, parameters and quality limits onto the product, in orderto enable autonomous production.
Before this can be implemented across the board, anumber of challenges relating to the semantics (terminology) have to be addressed. However, one important aspect in the Industry 4.0 has already been
settled in practice: The communication between
product and plant will take place via OPC UA.

SAP
Manufacturing
Execution
SAP Plant
Connectivity
(PCo)

-

Validate PCN: correct step in the work schedule,
status not locked or reject
Validate machine: status not in maintenance or locked

Validate
PCN andmachine

Send“StartResponse”- OK- NOK/fault info

- User- Site- Resource-ID- Operation
- PSN

UA
OPC

Save
further
process data

OK

Log
PCN

Register PCN
and MESWeb service“Start”

Executeprocess

OK

Analyze
response

NOK

Error
handling

NOK29

Vertical: OPC UA plus UMCM – The “USB connector” between PLC and MES

Vertical:Semantic information models for MES
Angelo Bindi, Senior Manager Central Control and Information Systems at Continental Teves –founder member and executive board MES DACH

The journey is the reward …
We all understand that we need a route, if we want toget from A to M. This is also true in automation technology. From the machine (automation level) wehave to communicate with higher-level systems(MES – Manufacturing Execution Systems). The MES
D.A.CH association has set itself the goal to make
MES tangible – literally. To this end it is necessary todescribe data based on their form and shape – i.e.
through a data model – and through their content –i.e. overall through semantics.
In the MES D.A.CH association we implemented thiswith UMCM (Universal Machine Connectivity for
MES) – i.e. an integrated communication model formachine data towards higher-level systems that is

optimized for the lowest common denominator.
However, this alone is not sufficient. It is necessary totake a route that is safe, fast, standardized, easy torecognize and extendable if required. OPC UA offers
an unrivalled, integrated system that is safe acrossdifferent security layers and nevertheless extendable,
if required. Optimum bidirectional communication isthus assured for the future.
Based on OPC UA, the MES D.A.CH association together with the OPC Foundation offers blocks according to IEC 61131-3 for different PLC suppliers
and high-level languages that enable convenient andfast implementations.
This is an efficient and simple method to make systems “Industry 4.0”-capable.

30

OPC UA Solutions

Human-Machine Interaction: OPC UA in a Browser»OPC UA provides a continuous communication
all the way to the web browser, with that it provides the foundation for the flexibility requested
in the field of Industry 4.0 and Internet of Things«
PD Dr.-Ing. Annerose Braune, Faculty of Electrical and Computer Engineering, Institute of Automation,
Dresden University of Technology

At the Institute of Automation it has been recognized
early on that also in the field of industrial SCADA systems the trend is towards mobile applications. Dueto the continuously growing variety of handheld devices, browser-based solutions are especially suitable.
In cooperation with the company ascolab GmbH aproject has been started in 2009 which addresses
the research regarding direct access to OPC UA servers by means of JavaScript. The advantage of using
JavaScript is that no special browser plug-ins arenecessary.
The hybrid profile of the OPC UA communication
stack, providing an ideal combination of capability
and speed, offers good conditions for a high-performance solution. This is accomplished by means ofusing a binary encoding in conjunction with information transmission via HTTPS. As HTTPS has to benatively supported by every web browser, computationally expensive encryption algorithms don‘t haveto be performed within JavaScript.

Hybrid Profile

Serialization
Layer:

Secure Channel
Layer:

Transport
Layer:

BinaryEncoding(HTTPS)HTTP(S)

The prototype developed during the project uses
these benefits and makes it possible to easily create
JavaScript based OPC UA Clients. Mobile browsers
are widely supported as well (see table). The OPC
UA server delivers the user interface and the script
code to the browser using a proxy server or directly
by having an integrated (minimal) web server.
Time measurements show that web-based applications cannot keep up to the performance of native
solutions but are quite sufficient for typical use cases. This also applies when using modern mobile
devices like smartphones or tablets, allowing the access to the data of an OPC UA server directly fromwithin the facility (e.g. for maintenance purposes).
Further developments address the integration of additional features such as support of alarms and authentication mechanisms.

Desktop

Mobil

Android Browser 4.3

Firefox 25

Opera Mini 7.5 (Andr.)Opera 17

Opera 16.0 (Andr.)



IE 11



Chrome 30 (Andr.)

Chrome 30

31

Smart Metering: Consumption information from the meter right up to IT accounting systems

Safe and flexible:
Meter data collection with OPC UA
Carsten Lorenz, AMR (Automatic Meter Reading) Manager at Elster GmbH“A safe and reliable communication protocol plays
an important role in smart metering”, says Carsten
Lorenz, AMR (Automatic Meter Reading) Manager
at Elster GmbH, a leading supplier of smart meterproducts for gas, water and electricity. Our UMI (Universal Metering Interface) protocol ensures optimum
energy efficiency and long battery life in networks.
At Elster, we offer a software with OPC UA interface for our own systems as well as other head-end
systems, since many systems used by supply companies already support this established standard.
Integrated encryption of sensitive meter data is an
important argument for OPC UA“.
Safety and encryption of personal data is a MUST
when Smart Metering is introduced. This means:
Corresponding safety concepts have to be introduced together with Smart Metering in existing andnew systems. They have to take account of new processes such as exchange of encryption mechanisms
between manufacturers and energy suppliers.

Metering Application

Data Collection Engine

Communication protocols are transferred in encrypted form with respect to gas meters. This means:
Personal data and critical commands, such as closing and opening of a valve integrated in the meter,are not visible for third parties and cannot be intercepted or simulated.
The communication protocols support both asymmetric and symmetric state-of-the-art encryption
methods, such as the Advanced Encryption Standard (AES). AES encryption is approved in the UnitedStates for government documents with maximum
security classification.
Smart Metering is the precursor for the energy infrastructure of the future. Transparent online displayof consumption data offers customers the option to
optimize their energy consumption and utilize flexible
tariffs based on their device and energy mix.

Meter Data Management System
SSL

Remote API
Elster Open Meter Data
Collection Engine

Internet

Meter DataManagement

Billing
Management

OPC-UA API
Asset
Management

APN

GSM / GPRS

etc.

32

OPC Foundation

OPC Foundation – organization
33 % NORTH AMERICA

48 % EUROPE

OPC
Organization
Members
6 % JAPAN
5 % CHINA
8 % OTHER

With more than 450 members, the OPC Foundationis the world‘s leading organization for interoperability
solutions based on the OPC specifications.
All members, including corporate members, end users and non-voting members, are committed to integrated, compatible communication between software-driven devices, including CPS, in industrial
automation environments.
The OPC Foundation offers a marketing program including a newsletter, website and various training
and information events aimed at manufacturers ofautomation solutions and providers of OPC technology. Member companies offer events and training
programs for end users of the OPC technology. The
cooperation of developers and users in working
groups is crucial to ensure that practical requirements and user feedback are taken into account in
the specifications.
Independence
The OPC Foundation is a non-profit organization thatis independent of individual manufacturers or special
technologies. The members of the working groups
are provided by the member companies on a voluntary basis. The organization is financed entirely frommembership fees and receives no government
grants. The organization operates worldwide andhas regional contacts on all continents. All members
have identical voting rights, irrespective of their size.
Member distribution
Although the head office is in Phoenix, Arizona, mostmembers (almost 50 %) are based in Europe. Around
one third of the members are based in North America. All main German manufacturer of automation
technology are members of the OPC Foundation
and already offer OPC technologies in their products.
Membership benefits
Members of the OPC Foundation have full access to
the latest OPC specifications and preliminary versions. They can take part in all working groups andcontribute requirements and solution proposals.
Members have free access to core implementations
and sample code. In addition, script-based test andanalysis tools are provided.
Manufacturers of OPC-capable products can havethese certified in accredited test laboratories. The
developer and user community meets at events forexchange of information and networking. Each year
three times a week-long interoperability workshop(IOP) is held, at which the latest products and theirinteraction are tested.

OPC FOUNDATION – RESOURCES

33

OPC Foundation provides specifications
and information

Resources
The distribution of a technology is based on the persuasion of the users and their understanding of thefunctionality and the technical details, plus simple
implementation and verification and certification. The
OPC Foundation offers users and particularly its
members a number of information sources, documents, tools and sample implementations.

➞ 1. Basic specifications. These contain the basic
concepts of the OPC UA technology and the security model, plus an abstract description of the
OPC UA metamodel and the OPC UA services. In
addition they describe the concrete OPC UA information model and its modeling rules, plus theconcrete mapping at the protocol level and theconcept of the profiles for scaling the functionality.

OPC UA specifications and IEC 62541
The main source of information are the specifications. They are publicly accessible and also available
as an IEC standard series (IEC 62541). Currently 13
OPC UA specifications are available, subdivided into
three groups.

➞ 2. Access models. These contain extensions of
the information model for typical access to data,
alarms, messages, historic data and programs.

Core Specification Parts

Access Type Specification Parts

Part 1 – Concepts

Part 8 – Data AccessPart 2 – Security Model

Part 9 – Alarms & Conditions

Part 3 – Address Space Model

Part 10 – Programs

Part 4 – Services

Part 11 – Historical AccessPart 5 – Information Model

Utility Type Specification Parts
Part 6 – Service Mappings
Part 12 – Discovery
Part 7 – Profiles
Part 13 – Aggregates

IEC62541: OPC UA specifications➞ 3. Extensions. These contain additional solutions
for find of OPC UA-capable components and theiraccess points in a network, plus the description of
aggregate functions and calculations for processing historic information.
Website and events
A further source of information is the global websiteof the OPC Foundation plus regional sites for Europe, Japan and China. This is where the products
made available by the members and their certification results are published. Information on technology
and collaborations is provided in different languages.
In addition, information on events organized by the
OPC Foundation itself and its members is provided.

34

OPC FOUNDATION – RESOURCES

Source code and certification for members

Source code and test tools
To ensure compatibility, the OPC Foundation offers
its members the implementation of the communication protocols, plus a certification program, including
the tools required for verifying and testing the conformity of applications with the specification.
➞ 1.
 OPC UA stack.
The communication stacks are available in three programming languages: ANSI C for scalable implementation on virtually all devices, in managed C# forapplication with the .Net Framework from Microsoft,
plus an implementation in Java for applications incorresponding interpreter environment. These three
implementations ensure the basic communication in
the network. They are compatible with each otherand are maintained by the OPC Foundation. Members have free access to the stacks and their source
code.
➞ 2.
 Certification program. For testing and certification of logically correct behavior, the OPC Foundation offers its members a test software (compliance test tool). It can be used to verify the
logically correct and specification-compliant behavior of an OPC UA application. In independentcertification laboratories manufacturers can havetheir OPC UA products certified based on a defined procedure. In addition to conformity the behavior in fault scenarios and interoperability withother products is also tested.

Interoperability workshops
The OPC Foundation holds three times a week-longinteroperability workshop (IOP) per year, at which
members can test the interaction of their products.
The IOP Europe takes place in the autumn at Siemens AG in Nuremberg. Other IOPs are held in North
America and Japan. These meetings offer a comprehensive test environment with around 60 –100 products and bring developers and testers together.

OPC UA availability

35

OPC UA start-up assistance

Code and advice
The OPC Foundation manages the three OPC UA
communication stack (C, .NET and Java) in order toensure interoperability at the protocol level. Althoughmembers have access to the source code of thestacks, many members decide to use a commercial
toolkit in view of the fact that, in addition to the actual communication layer for an OPC UA server, further specific administrative functions have to be implemented. This is where the toolkits come in, which
consolidate generic functions such as connection
management, certificate management and security
features.
The toolkits and developer frameworks are alsoavailable to non-members. The offer advantages for
implementation and time to market.
Expert knowledge
In Germany, several companies offer commercial
support for the integration of OPC UA communication technology in existing products and the implementation of new products, ranging from advice and

OPC
From Data Access to
Unified ArchitectureISBN 978-3-8007-3217-3

OPC
UnifiedArchitecture
ISBN: 978-3-5406-8898-3

developer training to the sale of software libraries
and development support right up to long-term
support and service contracts.
The toolkits are available as binary “black box”
components or with the full source code. In addition to the source for the OPC UA stacks of the
OPC Foundation, commercial toolkits offer simplifications and convenience functions. The general OPC UA functionality encapsulated behindan API. This means that application developers
require no specific OPC UA expertise, since astable, tested library enables them to focus on
their own core competence.
Quality and function
OPC UA toolkits are used for a wide range of application scenarios in industrial environments.
They are robust, certified, maintained and arecontinuously improved further. The toolkit providers offer specialized and optimized developer
frameworks for different programming languages. The toolkits differs in their OPC UA-specificfunctionality and in terms of their application andoperational environment. In parallel with all toolkits professional support and development support is offered. Further information is available
from the toolkit manufacturers.

36

Headquarters / USA
OPC Foundation
16101 N. 82nd Street
Suite 3B
Scottsdale, AZ 85260-1868
Phone: (1) 480 483-6644
office@opcfoundation.org

OPC Europe
Eiserstrasse 533415 Verl
Germany
stefan.hoppe@opcfoundation.org

OPC Japan
c/o Microsoft Japan Co., Ltd
2-16-3 Konan Minato-ku, Tokyo
1080075 Japan
opcjapan@microsoft.com

OPC China
A-807, Jia Hao International Center, No 116
Zizhuyuan Road, Haidian District
Beijing, 100097
P.R.China
opcchina@opcfoundation.org
V2

www.opcfoundation.org