1OPC Unified Architecture
The Interoperability Standard

Multiplatform
Multivendor
SecureReliable2

OPC: Openess – Productivity – COLLABORATION

Welcome to the OPC Foundation,a global organization in which users,
vendors and consortia collaborate
to develop standards for multivendor,
multiplatform, secure and reliableinteroperability in industrial automation and other markets.

3

The OPC Foundation
The OPC Foundation is dedicated to ensuring interoperability in automation. By creating and maintaining open specifications that standardize the communication. This communication includes acquired
process data, alarm and event records, historical
data and batch data. The information is transferred
vertical and horizontal from multivendor enterprisesystems and between production devices. Production devices include sensors, instruments, PLCs,
RTUs, DCSs, HMIs, historians, trending subsystems,
alarm subsystems, and more. These systems areused in the process industry, manufacturing, and inacquiring and transporting energy, oil, gas and minerals.

Thomas J. Burke
President and Executive Director
OPC Foundation

OPC is the interoperability standard for secure, reliable multivendor, multiplatform data exchange forIndustrial Automation. It provides open connectivity
across multiple products, regardless of hardware
platform or software operating system.
The OPC standard is a series of specifications thatare developed by industry vendors, end-users andsoftware developers to facilitate data transmission
and exchange. OPC specifications define an interface between clients and servers, as well as servers
and servers, for different fields of applications, including access to real-time data, monitoring ofalarms and events, access to historical data andother applications.
Since 1995 OPC has been gaining widespread
adoption across multiple industries. OPC Classic
was first released in August, 1996 with support for
Microsoft Windows. With the introduction of serviceoriented architectures in industrial automation systems, the OPC Foundation released the first OPC UA
specification in 2009 which provides a migration
path from OPC Classic to more secure and scalable
solutions that take advantage of Web services and aunified data model.

Today there are over 20,000 OPC products from
more than 3,500 vendors with millions OPC based
applications installed worldwide. This reinforces OPC
technology as the leading standard for interoperable
data exchange between software applications frommultiple vendors.
The OPC Foundation’s vision is to manage a globalorganization in which users, vendors and consortia
collaborate to create data transfer standards for multivendor, multiplatform, secure and reliable interoperability in industrial automation.

Openess

Productivity

Collaboration2	
OPC: Openess – Productivity –CoLLABORATION– > 450 members– Platform-neutral– All areas of application– All connections– Industry standard– Manufacturer-independent– Interoperability– Reliability– PLCopen– BACnet Interest Group– FDI Cooperation– EDDL and FDT– MESA, MES-D.A.CH.
– OMAC– Mimosa, ISA-95, ISA-88– MTConnect– Smard Grid
– ODVA– MDIS

4 Quotes

To support this vision, the OPC Foundation :➞ Creates and maintains specifications.
➞ Ensures compliance with OPC specifications
via certification testing.
➞ Collaborates with industry leading standard
organizations.
This brochure will help you better understand OPC
UA technology and what the OPC Foundation can
provide to your organization. For more information,please visit the OPC Foundation website atwww.opcfoundation.org.

Sincerely,
Thomas J. Burke
President and Executive Director
OPC Foundation
thomas.burke@opcfoundation.org

Contents

6 OPC UA at a Glance
8 OPC Foundation Organization
10 OPC UA Technology in Detail
16 Compliance and certification
18 Case Studies
26 OPC UA is IEC62541

The OPC Vision

27	Further information
The Vision of the OPC Foundation is to provide thebest technology, specifications, certification and processes to enable companies to build products andservices that demonstrate multiplatform multivendor
secure reliable interoperability. OPC Foundation
members benefit by being able to take advantage ofthe technology and marketing necessary to become
leaders in the industry supporting industrial standards for industrial automation and other markets.

4

Quotes»As a founding member of the OPC Foundation,
Siemens strives to create added value for its customers through driving automation as well as the further development and interoperability of technologies between different system manufacturers.
In many of our innovations – such as the network
management solution Sinema Server, the Human
Machine Interface Simatic HMI, or the flexible, modular motor management system Simocode pro – OPC
standards have been applied. OPC UA is an implementation we attach especially great relevance to.
Thus, we have always been strongly involved in thisfield, and were among the first companies to havetheir products certified. «5»OPC UA is now available on the market and is proving to solve the key issues it was intended to. Honeywell is investing in OPC UA and expects to provide
leadership to ensure there is market acceptance andadoption. This is an exciting evolution for the OPC
Foundation as it effectively solves many existing
problems and expands the applicability of OPC far
beyond its current accepted scope historically.«»OPC UA is the future oriented communication standard for the industry. The emergence of the 4th industrial revolution will boost the need for OPC UA.«
Dr. Reinhold Achatz, Head of Corporate Center Technology, Information &Quality, ThyssenKrupp AG, Former OPC board member and Vice President
from 1996 till 2012.

»OPC UA allows a platform independent, easy andsecure connection between SAP business systems
with distributed shop floor data even on smallest embedded devices.«
Veronika Schmid-Lutz, Product Owner Manufacturing, SAP AGDavid Eisner, Honeywell, OPC board member

Thomas Hahn, Siemens AG, OPC board member»OPC UA unlocks the potential for ERP to Factory
Floor communications“.«Commitment from Industry Leaders

Dr. Jürgen K. Weinhofer, Vice President Control Architecture & Technology,
Rockwell Automation, OPC board member»ICONICS is well positioned to take advantage of the
new OPC UA interoperability standard with its newest SCADA, HMI and Analytics products which aredesigned to be “OPC UA to Core“.«
Russ L. Agrusa, CEO ICONICS, OPC board member»Just as the OPC Foundation once transformed data
access and interoperability for industrial applications
on the PC platform, it stands on the threshold of another wave of transformation represented by the potential of the Internet of Things. Connected devices
together with cloud services, unlimited storage, andopen standards for security and communications areenabling Intelligent Systems, paving the way for a
new wave of insights, applications and businessmodels across the manufacturing landscape. The
OPC UA standards play a key role in enabling thistransformation and Microsoft is committed to working with the OPC Foundation to best help meet it’sneeds.«
Rohit Bhargava, CTO WW Manufacturing & Resources Sector, Microsoft
Corporation»OPC DA is the most popular and successful standard interface on the automation systems. Yokogawa joins OPC Foundation from the beginning andhas much contributed to the development of OPC
interface. Now Yokogawa is fully committed itself to
new promising OPC UA and will contribute to thedevelopment as ever.«Nobuaki Konishi, Yokogawa, President OPC Council Japan,
OPC board member»Emerson, as a founding member of the OPC Foundation, has and will remain committed to the vision of
the OPC Foundation to develop standards for open
connectivity in industrial automation systems andadjacent domains.«
Dr. Grant Wilson, Emerson, OPC board member»Beckhoff joined OPC Foundation in 1998 and earlyprovided OPC UA functionality integrated into smallest embedded controller in 2008. Actively pushing
the collaboration with PLCopen our customers already benefit from easy, secured connection fromour open PC based control philosophy up into MES
and cloud scenarios.«
Hans Beckhoff, Managing Director, Beckhoff Automation GmbH

OPC UA at a Glance

6

7

OPC UA at a Glance – Secure, reliable andplatform-independent data communication

es
am
nf
r
s

M

ai

Workstation
Serverers

SecurityStandardized Communication via
Internet & Firewalls
OPC UA supplements the existing OPC industry
standard with important features such as platform
independence, scalability, high availability and Internet capability. OPC UA is no longer based on DCOM,
but has been conceived on the basis of a serviceoriented architecture (SOA). OPC UA can therefore
be ported very easily. Today, OPC UA already forms
the bridge between the Enterprise level down to embedded automation components – independent ofMicrosoft-, UNIX- or any other operating systems.

stertimized TCP-based UA
binary protocol for dataexchange with a standard
IANA defined port “4840”;
Web Services and HTTP
are additionally supported. It is sufficient to open
up just a single port in a
fire­wall. Integrated security me­­chanisms ensure
secure communication via
the Internet.

Availability and Reliability
OPC UA defines a robust architecture with reliablecommunication mechanisms, configurable timeouts,
and automatic error detection and recovery mechanisms. The communication connections between
OPC UA clients and servers can be monitored. OPC
UA offers redundancy features that can be applied toserver and client applications to prevent loss of data
and to implement highly available systems with maximum uptime.

lu➞ OPC UA uses an op-

C

Standardized
communication
via Internet andvia firewalls

Protection against
unauthorized Access
OPC UA technology uses a mature security concept,
ensuring protection against unauthorized access or
sabotage of process data and as well against errors
due to careless operation. The OPC UA security
concept encompasses options for user authentication, the signing of messages and the encryption of
the transmitted user data. UA security is based on
proven standards which are used also for secure Internet communications like SSL, TLS and AES.

Platform independent data
communicaton
OPC Unified Architecture is the new technology generation of the OPC Foundation for the secure, reliable and vendor-neutral transport of raw data andpre-processed information from the sensor and fieldlevel up to the manufacturing level and into the production planning or ERP system. With OPC UA, alldesired information is available to every authorized
application and every authorized person at any timeand in any place. OPC UA is independent of the
manufacturer from which the applications originate.
It is independent from the programming language inwhich the applications were developed. And it is independent from the operating system on which thesoftware is used.

Desktop PC
Notebook
Phone

PLC Controller

D

ev

ic

es

Po
r

ta

bl

es

D
es

kt

op

s

Se

rv

➞ X509 certificates➞ OpenSSL encryption➞ User / password➞	Access rights for each
attribute

Embedded devices

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

Variables
_____
_____
_____

Methods_____( )_____( )_____( )EventsN
N
N

MethodService Set(Programs)

Subscription
Service Set(Alarms &Conditions)

Simplification by Unification
OPC UA defines an integrated address space and an
information model in which process data, alarms,
historical data and program calls can be represented. OPC UA unites classic OPC features and allows
complex procedures and systems to be described in
a component.

OPC UA makes it possible for standardization organizations to use UA services as a transport mechanism for their own information protocols. Today the
OPC Foundation cooperates with different standardization groups such as PLCopen, BACnet, ISA or
FDI. They create companion specifications by using
UA modeling capabilities.

Range of Use
The versatile usability of the OPC UA technology enables the implementation of completely new vertical
integration concepts. By cascading OPC UA components, information is transferred securely and reliably from the shop floor to the production planning
or ERP system. Embedded UA servers at the fielddevice level, UA components at automation level andintegrated UA clients in ERP systems at enterpriselevel are directly connected with eachother. The respective UA components can be geographically distributed and easily separated from one another by
firewalls.

Investment Protection
OPC UA will replace classic OPC in the long term. In
the mid term however, DCOM-based OPC products
and UA products can co-exist. The migration strategy of the OPC Foundation enables the combinationof classic OPC and OPC UA products. The installedbase of existing OPC products with millions of installations will work with the new OPC UA products, so
migrating to OPC UA is painless and offers advantages to the user because any desired product fromany manufacturer, whether OPC or OPC UA can be
used.

8

OPC Foundation Organization

9

OPC Foundation – The Community of Visionaries
and Communication Experts

Connect with the OPC Community
With more than 450 member companies, the OPC
Foundation is the world’s leading community for interoperability solutions based on the OPC specifications. All OPC Foundation members – including corporate, end-user and non-voting members – canproudly display the OPC Foundation logo and the

OPC Foundation Member logo. For the OPC technology suppliers, the OPC Foundation offers a complete marketing program, including a newsletter, website and educational events. For the OPC end-usercommunity, membership offers the chance to collaborate with the OPC developer community to build
best-in-class solutions.

OPC FOUNDATION MEMBERS
The OPC Foundation member companies are located inevery major region of the world, Europe, North and SouthAmerica, and Asia.
33 % NORTH AMERICA

48 % EUROPE

OPC
Foundation
Members
6 % JAPAN
5 % CHINA
8 % REST OF WORLD

Why Join the
OPC Foundation?

Corporate Members
are the OPC technology providers that offer OPCcompliant products. Membership dues are based on
annual sales and include free product certification
testing, based on membership class.

➞ Obtain full access to the
OPC specifications➞ Get free use of the OPC
Foundation sample
code

Non-Voting Members
are organizations such as government and research
institutions, universities and non-profit groups thatneed OPC information but who do not build OPC
products for the open marketplace.

End-User Members
are the consumers of OPC technology in the form of
OPC-compliant products. End-user members cancontribute to the advancement of OPC technology
by commenting on Draft Specifications.

➞ Certify products at the
OPC Foundation
Certification Lab.
➞ Connect with the OPC
developer and user
community.
➞ Harden you productin interoperability (IOP)
workshops.

Create the Future
The OPC specifications define the interface between
clients and servers, as well as server to server (peerto peer), for different fields of applications, including
access to real-time data, monitoring of alarms andevents, access to historical data and other applications.
Benefits of membership
As an OPC Foundation corporate member, you getcomplete and early access to the OPC specifications
before the general public. You can even join working
groups and engage in the development of ongoing
specifications.

How to Join
Becoming an OPC Foundation member is easy!
Membership provides the best way to stay up-todate with technology and to reach the community
most interested in the value and benefits of OPC
technology. Download, review, and complete themembership application atwww.opcfoundation.org/howtojoin.
If you have questions about the application process
or membership, please contact the OPC Foundation
at membership@opcfoundation.org.

THE OPC FOUNDATION IS …
COMMUNITY:COMPLIANCE:COLLABORATION:➞ The world’s leading community➞ The official source for the➞ The collaboration with other or-for interoperability solutions based

OPC Certification Program, ensur-

ganizations advances the adoption

on OPC specifications that delivering OPC products plug and play inand use cases of OPC based

universal connectivity.

real-world applications.

products.

10

OPC UA Technology in Detail

11

OPC UA Technology in Detail

The technical working group for OPC Unified Architecture was formed in 2004. The objective was thedesign and creation of a communication technology,
which functionally unifies all existing classic OPC
specifications, but also addresses platform independence and object orientation. At the end of 2006 thenew technology was presented to the public. The
new service oriented architecture (SOA) incorporates
modern security standards and object oriented meta
model. It is scalable from embedded devices up toenterprise systems. Together with the release of thespecification in 2008 the first reference implementations in ANSI C and .NET were available, Java followed one year later.

Protocol Binding
The OPC UA specification defines abstract services
following service oriented architecture (SOA). The“Service Mapping” part of OPC UA specifies several
protocol bindings to map these services to a network transport. Currently there are four (4) protocol
bindings defined of which one, the UA Binary, ismandatory.
➞ Native UA Binary (mandatory)➞ HTTPS with UA Binary➞ HTTPS with SOAP and XML Encoding➞ HTTP with SOAP and WS SecureConversation
and XML Encoding

BinaryVendor Specific Extensions

AC

Webservices

UA BinaryCollaboration Models

DA

HybridHA

Prg

WS Secure
Conversation

UA Secure
Conversation

HTTPS

The key components of the Unified Architecture are:➞ different protocol bindings➞ object oriented modeling capabilities➞ fixed set of base services➞ OPC information model➞ extendable by collaborating organizations➞ extendable through vendor specific extensions

HTTP

TCP / IP

4840

BaseNode

ObjectVariable

Method+EventNotifier: Byte

+Value+DataType: Nodeld+ValueRank: Int32+ArrayDimensions: Int32+AccessLevel: Byte
+UserAccessLevel: Byte
+MinimumSampleInterval: Int32+Historizing: Boolean+Executable: Boolean+UserExecutable: Boolean

ObjectType+IsAbstract: Boolean

DataType

View+IsAbstract: Boolean+ContainsNoLoops: Boolean+EventNotifier: Byte

SOAP

Base Services

Meta Model

Data Model
OPC UA defines a generic object model including
the corresponding type system. In addition to the generic data model, modeling rules are defined that
describe how any physical system can be transformed in an UA conformant model representation ofthat particular system. With this data model any kindof equipment, function and system information canbe described. The base type system supports relation between objects, so called references, and it
supports multi inheritance, hence it is comparable toany modern object oriented programming language.
This base model provides object and variable types+Nodeld : Nodeld+NodeClass : NodeClass+BrowseName : QualifiedName+DisplayName : LocalizedText+Description : LocalizedText

UA XMLUA TCP

Transport

The mandatory UA Binary protocol is intended to be
used by all UA enabled software and devices. It ishighly optimized and extremely fast, hence it is thepreferred protocol between embedded devices,
SCADA/HMI level devices and DCS systems. TCP
port 4840 is reserved for OPC UA Binary transport.
The Hybrid protocol runs UA binary encoded content
inside an https message frame. Instead of message
based security this binding uses TLS encryptedtransport security. Hence it is still fast and efficient,and it can be implemented down to low end andmidrange level devices. In a wide area network(WAN) the TCP port 443 will be open on all firewalls

443

443

ReferenceType

VariableType+IsAbstract: Boolean+Symmetric: Boolean+InverseName: LocalizedText+Value+DataType: Nodeld+ArraySize: Int32+IsAbstract: Boolean

80

The OPC Foundation provides protocol implementations in the form of communication stacks written inthree (3) different programming languages to its
members, ANSI C, C# and Java. The stacks aremaintained by the OPC Foundation to insure interoperability. Each stack provides a language specificAPI, the service encoding layer (binary or XML), thesecure channel layer and the transport layer.

allowing the Hybrid protocol pass through. The Hybrid is intended to be used in web client applications
or in cases where only port 443 can be used.
The web service binding runs on http, typically on
port 80, using WS secure conversation for message
based security or transport layer security with https.
The XML encoded message including SOAP header
requires more powerful processing. The intended
use case is the communication between enterpriseapplications and high level systems that are alreadyused to handling web services and that are only permitted to communicate on port 80. Those systems
typically will not require direct access to field level
devices.

as well as reference and data types. Given that, as
the basis, OPC UA can describe any kind of data
including it’s meta data and semantics.
The UA data model is the foundation of the UA Information Models, which are specialized models thatenhance the basic set of models to provide certain
functionality like Data Access, Alarms and Conditions, Historical Access or Programs.

Standard UA Server

PLCopenDevice Integration

MethodServer Facet

13

Redundancy

Event Subscription
Server Facet

Complex Data

Alarms & Conditions

Historical Access

OPC UA Technology in Detail12

50 Sessions

embedded UA Server
micro UA Server

2 Sessions

5 Subscriptions

1 Subscription

Address Space

2 Subscriptions

Type System

Binary Protocol

Core

Security

Data Access

Services
Independent from the transport binding, OPC UA
defines a fixed set of services that must be supported by all UA servers. In contrast to classic web service protocols this abstract service definition guarantees a defined and interoperable set of functionality
which the communication partner can rely on. These
services are fixed in terms of the signature of parameters and their behavior. They are grouped into functional blocks depending on their task, the so called
service set. Even though a server must propagate
functionality, a basic set of services is mandatory for
all servers to insure minimum of basic functionality
like connection establishment.

ProfilesThe functionality of an OPC UA Server can be precisely described in terms of profiles. Profiles arecompositions of conformance units defining thesmallest possible set of services required for certain
functionality. The UA client as communication partner can rely on the supported profiles and expectedbehavior. The compliance certification program insures that UA servers and clients behave within thelimits of their supported profile. A conformance unit
is also a testable and certifiable functionality. The
concept of profiles is the key to scalability of the OPC
UA technology. E.g. servers following the “embedded UA Server Profile” need to support fewer connected clients and parallel subscribed nodes compared to a “standard UA Server Profile”. Memory andresource consumption becomes predictable andthus can be handled by the embedded devices. A
UA server running on a powerful PC platform is expected to support more parallel connections. However, and that is the important part, they both use theexact same services for the same functionality e.g.
read and write of their data points. When a server
supports the full profile of a “Standard UA Server” it
can be easily enhanced. By adding event subscriptions and method facets to the full featured profile, it
becomes an Alarms&Condition UA Server. A detailed
list of profiles and their contained conformance units
can be found on the OPC Foundation website:www.opcfoundation.org/profilereporting

Information Model
From a functional point of view, UA information models unify the classic OPC specifications data access(DA), alarms and events (A&E), historical data access(HDA) plus the two previous specifications Commands and Complex Data. The new UA node represents anything, starting from a simple variable up toa node object that encapsulates and fully represents
a machinery subcomponent or a complete machine.
An object may contain data variables, it can initiate
events and can provide callable methods, and it may
have historic information on values and events.
A server exposes instances – accessible nodes of acertain type – in its address space. The address
space can be organized in a hierarchical or non-hierarchical manner as nodes are interlinked by references in a full meshed network. UA defines so called“well known types” that cover all use cases known
from previous OPC functionalities, but the UA typesystem is extendable. Custom types can be inheritedand enhanced, but also complex types can be composed as needed. A client can generically discoveror browse through the server’s instance and typesystem following certain references. Hence the client

Objects

will gather all required information to interpret thedata provided by that particular server. The beauty ofthis concept is that the data describes itself including
all metadata and semantic information.
OPC UA distinguishes between the types and theinstances when describing data models. For thatreason the OPC Foundation has defined a graphicalsyntax according to UML, but enhanced for special
OPC UA needs. The DA Information Model of UA for
example enhances the base variable type with an
AnalogItemType, which defines standard properties
like range and unit to describe analog measurement
values. When composing an analog measurement
object type, which is derived from the BaseObject
type, it will use an AnalogItem type for the measurement value itself, but it also can include system andlevel alarm objects including their conditions. The UA
server on the measurement device or PLC, will now
have multiple instances of analog measurements, formeasuring pressure, temperature or any other analog value but all instances have the same node tree
below the instance nodes and the type node.

Object Instance AnalogMeasurement
Pressure

Measurement

InstrumentRange
EURange

Temperature_1

SystemAlarm
EngineeringUnits

Temperature_2

LevelAlarm

HH_Level
H_LevelService Set

Description

Discovery

Obtain endpoint and security information needed for connect attempt

SecureChannel

Establish a secure end-to-end communication channel

SessionCreate and manage sessions and authenticate user credentials

NodeManagement

Modify the address space of a server

View, QueryBrowse and request filtered information and view on the servers address space

Attribute

Read and write values of variables and other node attributes including the history of data and events

MethodInvoke methods that a server may offer

Suscription, MonitoredItem

Monitor variable values for data changes and objects for event notifications

L_LevelObjectTypes

LL_Level

BaseObjectType

Object Type AnalogMeasurement
AnalogMeasurement

Measurement

InstrumentRange
EURange

SystemAlarm
EngineeringUnits
LevelAlarm

HH_Level
H_LevelL_LevelLL_Level

14

OPC UA Technology in DetailSecurity
OPC UA addresses all the security threads modern
interlinked industrial devices are facing today. Security is not optional and was built into the core of OPC
UA. The core security features of OPC UA are:➞ Authentication➞ Authorization➞ Confidentiality➞ Integrity➞ Auditability➞ Availability

15

features. Similar to the WS SecureConversation
used in the web service binding, the OPC UA SecureConversation in the UA Binary protocol uses message-layer-encryption based on shared security context, the so called secure channel.
For double sided authentication of the applications
the well accepted asymmetric cryptographic PKI
mechanism using X.509 certificates is used. It fully
supports certificate authorities (CA) for easy administration and support of trusted chains in large networks. In addition OPC UA defines authorization
mechanism for application layer security in terms ofuser identification using user/password or personal

FeatureUA Native Binary

UA XML Web Service

Confidentiality

Options: encrypt all messages or encrypt only
channel management
Encryption: AES (symetrix), RSA (asymetric)

WS SecureConversation:
XML Encryption (WS Security)

Integrity

No message alteration: HMAC or RSA
encryption, SHA1 hash, periodical key change
No message sequence alterations: Nonce,
Timestamp

WS SecureConversation:
XML Signature (WS Security)

X.509 certificates are exchanged when the
secure Channel is establishedsecurity context establishment and sharing,session key derivation (WS SecureConversation)

Application Authentication

validate credentials, request and issue security
tokens (WS Trust) using any of:User/Password, Kerberos, X.509
User Authentication

Optional user security token types: User/Password, X.509, Issued Token like Kerberos andAnonymous
Server application can validate the user’s token

User Authorization

Product developer specifies user authorization scheme, implements scheme in server application

Auditing

All security events are recorded, traceable through intermediate nodes, minimum required set oflogged parameters (for interoperability)

Availability

Depends primarily on infrastructure and the Site for protection, minimum processing before
authentication

Besides the transport connection a UA client andserver build up a secure channel, a virtual end to end
connection on the communication layer and they establish a session, the virtual communication relation
ship, on the application level.
Integrity and confidentiality of the messages between
the communication partners is insured by signingand encrypting of messages. Keys are updated after
certain time and changed while communicating. Thisis an integral part of the communication stack. The
UA Stack interfaces provide both a Public-Key-Infrastructure (PKI) and crypto library to provide security

certificates. The individual data points within an OPC
UA server itself have access rights comparable to a
Linux file system (rwx). With a granularity down to asingle node with their attributes, a certain group orindividual user may be granted read access. Only an
operator or administrator may write a value to thisnode, whereas a guest may not even see or browse
this tag. OPC UA defines audit mechanisms to keep
track of who modified which value and when andthese audit events are logged in the server. Therefore
OPC UA is usable in food and pharmaceutical domains fulfilling FDA rules.

Platform Independence
The available communication stacks cover almost
every platform known today. The Java implementation requires Java runtime environment JRE1.6. andcan be run on Android based devices up to Windows or Unix based enterprise servers. The .NET
implementation requires Microsoft .NET Framework
3.5 which is available on XP up to Windows 7 and 8
Desktop including the 64bit variants.
The ANSI C implementation has the highest flexibility. It is completely platform independent and all operation system specific code is capsulated in a platform layer. There are platform layers available forWindows, Linux but also for real time OS like Windows CE, VxWorks, QNX, RTOS, and many others.
The ANSI C stack can be compiled for Intel, ARM
and PowerPC architectures and many others. It canbe optimized for a certain use case and it can run insingle or multi-threaded mode. It is currently the fastest of the three stacks and the smallest in size. In
addition there are implementations available that do
not even need an operating system. These bare metal C stacks can be used on microcontrollers and theycome with their own TCP implementation.
Speed and Throughput
Even though today’s TCP based bindings of OPC UA
are not suitable for deterministic hard real time communication, because they use standard TCP, the response time and the general speed and throughput
are impressive. Future protocol bindings may support deterministic communication, the abstract service definition of OPC UA supports priority handlingof publish messages.

All service calls in OPC UA are designed for accessing large amounts of data and at the same time reducing the used bandwidth as much as possible. For
fast access OPC UA defines all services as multinode function e.g. a single read request can readseveral thousand nodes at once. To avoid the transmission of thousands of node names in each request, OPC UA defines node registration service.
Once registered at the server, the following read services can use a handle for fast access and fast transmission of the data.
The subscription services monitor tags for changes
and only notify the changed values, such that the
bandwidth is minimized without loosing information.
For each subscribed node an individual sampling
rate and individual queuing allows extreme fast scanning of data at the data source. The server can send
the queued data at once, so that it gets publishedto the client by highly effective transmission over
the wire.
Robust COMMUNICATIONOPC UA communication follows the client-serverparadigm, even though it is expected that mostproducts will be both, client and server. The client
sends an asynchronous service request and receives
a response from the server. Every single service callcontains a configurable timeout until the client will
wait for response to arrive. This insures a highly responsive system. Sequence numbers are used to
identify the corresponding request/response message pairs.
When subscribed to notifications of events or valuechanges, each published response of data is acknowledged by the client with the next publish
request. In case of connection interruption or transmission failure the server keeps the unacknowledged
messages and resends them when connection isup again. Data collected in the meantime will bebuffered or queued by the server such that no data
gets lost during short network interruptions. OPC UA
insures robust data transmission without the loss ofdata, even on an unreliable transport medium.

16Compliance and certification

17

Certification Program –The Key to Successful Interoperability

Especially for OPC UA the OPC Foundation has enhanced the certification program. The end-users’
demand for high quality products and reliable communication led to the foundation of a dedicatedworking group inside the OPC Foundation. The
group has defined test procedures and test cases
including the development of test tools. The goal isto provide useful tools for testing and development
having highest possible coverage in automated testing. Not only compliance to the specification is tested, but also typical error scenarios and environmental conditions are evaluated. Ease of use is also a
focus of the certification program. Certified products
are listed as OPC-compliant products in the interactive OPC Product Guide on the OPC Foundation
web site.
Certification
OPC Foundation corporate members can test their
OPC server and client products at the OPC Foundation Certification Test Lab. Objective certification
testing by the independent test lab guarantees thatyour products comply with the following:➞C ompliance to the OPC Specifications➞ Interoperability with other vendors’ products➞ Robustness and recovery from disaster➞E fficiency of CPU, RAM, and bandwidth etc.
➞U sability insures a good user-experience.

Interoperability TestingIn addition to test lab certification, the OPC Foundation hosts workshops for interoperability testing(IOP), which are held around the globe. There arethree IOPs each year: North America, Europe andAsia. Members can participate and test their new
products against the software and devices of othermembers. During the five day session typically 40 to
60 products are tested. The high number of clientsand servers create an extraordinary test environment, you would never be able to set up on yourown. The IOP is an valuable endorsement of products. Each client participating must connect and interact with each server and execute a set of operations defined in a test matrix. The results of thesession are published in a database.
For many years the European IOP workshop has
been hosted by Siemens in Nuremberg, Germany.
Since 2010 there have been more UA products registered than classic OPC products showing thestrong commitment to OPC UA technology and interoperability of high quality products. During theevent you can meet and network with other developers, testers, and the core team of OPC UA technology enthusiasts.

Test Tools
There are different test tools available to validate thecorrect function of an OPC UA server or client product. As an OPC member you have access to all thetools and test code. Members also have access to
the OPC Compliance Test Tools (CTT) to ensure
OPC products meet the appropriate specifications.
The script based tool can be enhanced with self created product specific test cases. Also the CTT canbe integrated into your company’s automated system and regression test.

Certification that Matters»The Certification Programme is a key benefit of
OPC Foundation membership. Extensive functional
testing with the CTT and interoperability testing in thelab has helped us deliver a product of the highest
quality.«
Liam Power, Embedded Labs

»We achieved Independent confirmation of the highest product quality, which is well applicable as sales
argument and appreciated informative discussions
with OPC Senior Experts about further opportunities
with OPC UA.«
Rene Bernhard, Siemens»Becoming lab certified by the OPC Foundation instills confidence to our customers and potential customers that our software products are held at thehighest level of interoperability and reliability.«
Ron DeSerranno, Mobiform Software, Inc.

»With a global customer base, we hold our Matrikon
OPC products and solutions to the highest quality
standards. Based on this commitment to quality –we were pleased to work the OPC Certification lab tobe the first OPC vendor in the Americas to achieve
independent, 3rd party OPC UA Certification. The
lab personnel were experienced professionals which,helped make the process straightforward.«
Rod Stein, MatrikonOPC»No matter how much history exists on a product’s
OPC interface, there is nothing better than the endorsement from an independent party – especiallywhen it comes from the OPC Foundation, the organization responsible for the definition of these standards.«
Tony Paine, Kepware Technologies

18Case Studies

19

Machine Manufacturing

Renewable Energy

Arburg – OPC UA enables machine manufacturer delivery reliability

AREVA uses OPC UA for monitoring offshore wind farm

»We were looking for a globally accepted dataexchange standard and found it in the form of
OPC Unified Architecture.«
Michael Vieth, Group Leader TA Control Technology, ARBURG GmbH + Co KG

High delivery reliability throughcontinuously available key data
Customers of Arburg moulding machines can centrally manage product, tool and material master data,
as well as capture data online regarding order pro­
gress, machine status, process parameters andalarms.
They can also determine key data on orders in same
progress, production shifts and production quality at
any time. All this runs silently in the background via
an OPC UA connection between the host computer
system and the machine. This allows the user toreceive reliable data and enables them to use theexisting capacities to their fullest extent, and thusachieve high delivery reliability.

OPC UA was the favored technology in ‘Alpha Ventus’, an offshore wind park test site in the North Sea,
45 kilometers from the German coast. The fully automated wind turbine controlled by a Windows Embedded CE with IEC6-1131-3 logic and OPC UA
server is connected to operators to constantly monitor plant and equipment conditions remotely fromonshore control room on a .NET platform.
Compared to other open standards the inherent security and authentication mechanism of OPC UA
was the determining factor for this decision.
With a complex network infrastructure including different subnets and domains, connected via routers
Platform independence
through OPC UA
While the embedded OPC UA server runs under
VxWorks on the visualization CPU of the control
system, the OPC UA client runs in a Java environment, showing platform independence of the
OPC UA standard. Just as customers can connect their own host computer systems to the Arburg injection moulding machines via OPC UA,
the Arburg host computer system can accessthird-party injection moulding machines via OPC
UA.

and protected by firewalls, configuration and administration becomes a difficult and time-consumingtask. In the past VPN tunnels for secure transmission
and remote desktop connections were used, but
OPC UA includes encrypted transmission and adds
user authentication and audit functionality down toindividual data points.
The fast and secured communication, between industrial automation and the enterprise systems that
support OPC UA industry standards, delivered important business and technical benefits, reduced administration combined with high reliability machines
via OPC UA.

»The integration of OPC UA Client functionality
into our SCADA software was an important step
towards OPC UA technology.«
Bernd Zickert, Head of Development, Multibrid

20

Case Studies

21

Scientific

DiscretE Manufacturing

KU Leuven uses OPC UA for ground based observatory control
Astronomical observatories are complex distributed
real-time systems encompassing a wide range oftechnology domains. The integration of industrial automation components such as Programmable Logic
Controllers (PLCs) and supervisory software has long
been hampered by the lack of an adequate industrial
communication technology. With OPC UA, theselimitations are now eliminated and in addition a powerful new range of functionality has become available.
The extensive OPC UA support for standard communication paradigms and information modeling offers the engineers of the Catholic University of Leuven, Belgium the opportunity to shift from theirtraditional custom communication solutions towards
an industry standard, as they apply their research re-sults to the Mercator Telescope based at the international observatory of La Palma on CanaryIslands, Spain. Researchers of the KU Leuven
considered OPC UA suitable to serve as the“backbone” technology of ground-based observatory control systems. With respect to a “general purpose” middleware, OPC UA is naturally
more tailored to facilitate interaction between thecomponents of a heterogeneous and distributed
control system. The engineers proceeded by
implementing the control of a new scientific instrument and a new support for the tertiary mirrorof the Mercator telescope, on commercial PLCs
with on-board OPC UA server. These PLCs were
integrated within the Scientific Linux infrastructure of the observatory via OPC UA.

Elster GmbH connect shop floor to SAP ME top floor
Elster uses SAP ME as theirstandard for traceability andprocess controlling“More customers demand comprehensive and fastaccess to production data.” Dr. Schlichtegroll, Key
Account Manager for OEM customers in the heatingenergy sector, sees a clear trend: “In the near futurea high-performance MES will become a key factor
for winning new orders.”
An MES roll-out places special demands on Manufacturing IT, such as safe and high-performance interfacing with production (shop floor control) and thehigher-level MES and ERP layers.
For direct communication based on high-level languages Elster uses the comprehensive SAP ME web
services interface. In most cases PLCs and machines have no option for calling web services. Thismeans that ideally a technology is needed that deals
with the communication to the MES system without
additional effort in the PLC source code. OPC UA
offers ideal prerequisites for this purpose.

Elster is using high-performance Windows Embedded CE controllers with an integrated OPC UA server
directly in the PLC, thereby simplifying the system
environment and keeping the PLC and OPC UA
server always in sync automatically. This results in afast connection but also easy to handle commissioning and service without special programming knowledge. Using OPC UA opens up new possibilities forlean PLC coding by using SAP ME routing information to control the assemble and test steps.
We see OPC UA as an important standard for ERP
communication via MES right down to the smallest
embedded system. Trends such as “Industry 4.0”
and “Internet of Things” show the way to comprehensive networking that goes far beyond the factoryboundary. Safe communication that is independentof the operating system is a prerequisite for achieving the smart factory aim.

4
1

Print Serial Number

2

Assembly3

Leakage Test

4

Functional Test

5

Packing

5

3

1

2

»OPC UA is a reliable, high performance andeasy to use interface which allows our PLC
software engineers to connect MES without
additional effort.«
Roland Essmann, Head of Laboratory Controls and Project Leader MES, Elster GmbH

22

Collaboration

23

Collaboration with other organizations

Cooperation with other standardization organisations was important for OPC UA from the beginning. The
simple extensibility by information models makes OPC UA very interesting for other standardization organizations. They only have to define which information has to be exchanged, but no longer how the informationmust be exchanged. Before the start of the OPC UA specification, it was one of the most important requirements that OPC UA, as a universal communication platform and IEC standard can form a basis for otherstandards.
OPC UNIFIED ARCHITECTURE COMPANION SPECIFICATIONSOPC UA consists of a list of specifications for the basic functions and the information models based on them,such as Data Access and Alarms & Conditions. Specifications that define further information models beyond
that are called Companion Specifications.
HOW ARE COMPANION SPECIFICATIONS CREATED?
OPC UA Companion Specifications are developed in various ways. One possibility is a working group of OPC
members within the OPC Foundation which defines an information model for special branches of industry or
areas of application. E.g. the specification OPC UA for Analyzer Devices (ADI) was created in this way on thebasis of customer requirements. Another possibility is a common working group with one or more other organisations with the objective of defining an OPC UA information model for a standard outside the OPC
Foundation. The information model OPC UA for IEC 61131-3 was created in this way with PLCopen.

➞ Information model in a standardized format– provide semantic identical access to various
vendor PLC’s➞ PLCopen-OPC UA function blocks enable– Controller act as UA client– Controller invoke methods in UA server➞ Vertical: Moving information from shop floor toenterprise➞ Horizontal: controller-to-controller connectivity➞ Secure, remote “out-of-the-PLCopen-box”
communication➞ Rapid engineering for HMI / MES / ERPInteroperability On The Next Level
The IEC 61131-3 standard defines various programming languages and a software model for the programming of control systems. The implementation ofthis software model on an OPC UA server address
space is defined in the combined PLCopen and
OPC Foundation specification. Thus, corresponding
OPC UA object types are created from declarationsof function blocks in the PLC and corresponding
OPC UA objects from instances of the function
blocks. The advantage is that a control program, regardless of the controller being used and the OPC
UA server, is always implemented in the same structure of objects in the address space.

»Communication is not about data. Communication is about information
and access to that in an easy 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, which is the foundation for a new communication age inindustrial control.«Collaboration

Eelco van der Wal, Managing Director PLCopen– PLCopen– BACnet Interest Group– FDI Cooperation– EDDL and FDT– MESA, MES-D.A.CH.
– OMAC– Mimosa, ISA-95, ISA-88– MTConnect– Smard Grid
– ODVA– MDIS

www.plcopen.org

24

Collaboration

25

UniversAL mAChine COnneCtivity FOr
mes – UMCM is: the neW stAndArd tO
COnneCt mAChines tO mes.
➞ Based on the PLCOpen ICE 61131-3 standard,
it defines a set of complex data profile required
by MES systems.
➞ OPC UA provides the fast, secured transport
from controller to MES in a semantic identicalway»The fusion of automation technologies and information technologies
requires 2 key elements. First – an intelligent network based system
which is able to create rule based decisions and which could store data
– that is a Manufacturing Execution System (MES) – and perhaps more
important, secondly – a communication layer that is fast, platform
independent, scalable, secure and could be integrated horizontally andvertically from the device level to ERP level – OPC UA. So we have –regardless of the location of the data storage – an industry 4.0 or aso-called cyber-physical system (CPS).«

www.mes-dach.de

OPC UA model
BACnetObjects

Typical Use-Cases of the
OPC UA / BACnet mapping:➞ Observation: Building automation may beobserved/controlled by enterprise systems andmulti-domain integration allows connecting
industry automation to building automation.
➞ Operations: Beyond simple data-exchange
access to historical data, alarms and schedule
programs offers a very detailed depth of integration.

OPC UA Information Model for BACnet➞ Cooperation between OPC Foundation and
BACnet Interest Group Europe➞ Enables BACnet enterprise integration
through OPC UA➞ Enables cross domain connectivity
Building Automation with BACnet
Industrial Automation with OPC UA➞ Engineering: The configuration of building
automation systems may be modified using the
mapping profile.
➞ Maintenance: Access to runtime information
like alarm-detection or schedule programs offers
configuration of BACnet devices from OPC UA
systems.

»The benefits of connecting BACnet and OPC UA are various. Building
automation components may provide data, alarms, schedule programs,
trend-log information and remote device management to enterprisesystems. Connecting OPC UA components to building automation
management systems or devices opens the connectivity to industry
systems.«

Angelo Bindi, Senior Manager Central Control and Information Systems,
Continental Teves, MES DACH Board member

Frank Schubert, Member of the Advisory Board of the BACnet Interest Group Europe

DEVICE CONFIGURATIONThe OPC UA services supported by the FDI server allows
safe and secure access to the device or to stored offline
data. Generic OPC UA clients can be maintenance tools or
a MES or ERP system.

FDI USES SCALABILITY OF OPC UA
The FDI standard allows the implementation of different
software architectures for a host. A host can be implemented starting from a tool for a single user up to a distributed
multi-user application with a client/server-architecture
which typically consists of three main components: FDI clients, an FDI server and one or more FDI communication
servers.

www.fdi-cooperation.com

www.big-eu.org

26

OPC UA Specification

FURTHER INFORMATIONOPC UA is IEC 62541

OPC Foundation Website

OPC UA technology was presented to the International Electrotechnical Commission (IEC). The national representatives worked closely together and
OPC UA quickly became an IEC standard. Thisshows the importance and relevance of OPC UA as
an internationally accepted and open standard thatis usable far beyond the industrial automation domain. Being an open IEC standard made OPC UA
the sustainable and credible communication technology for multivendor interoperability.

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

IEC Number

Release Date

OPC UA Specification Titel

IEC/TR 62541-1

February 2010

OPC Unified Architecture – Part 1: Overview and Concepts

IEC/TR 62541-2

February 2010

OPC Unified Architecture – Part 2: Security Model

IEC 62541-3

July 2010

OPC Unified Architecture – Part 3: Address Space Model

IEC 62541-4

October 2011

OPC Unified Architecture – Part 4: Services

IEC 62541-5

October 2011

OPC Unified Architecture – Part 5: Information Model

IEC 62541-6

October 2011

OPC Unified Architecture – Part 6: Mappings

IEC 62541-7

July 2012

OPC Unified Architecture – Part 7: Profiles

IEC 62541-8

October 2011

OPC Unified Architecture – Part 8: Data Access

IEC 62541-9

July 2012

OPC Unified Architecture – Part 9: Alarms and conditions

IEC 62541-10

July 2012

OPC Unified Architecture – Part 10: Programs

27

OPC UA Specification
The OPC UA specification is a multipart specification. In contrast to the COM based specifications,the UA specification is not only a user specification.
Most parts of the multipart spec describe OPC UA
internals, that are implemented and handled by the
UA communication stacks. This information is onlyinteresting for developers that want to port the UA
stack to other platforms or those who want to implement a new UA stack from scratch. However, UA
application developers will typically use only the API
documentation. For implementers of UA server andclients mainly the part 3, 4, and 5 are of interest.

Regional OPC Foundation Websites with all details
regarding regional activities can be found here:➞ Europe: www.opcfoundation-events.com➞ Japan: www.opcjapan.org/eng/index.asp➞ China: www.chinaopc.org

There are 3 groups categorizing
the multiple parts of the OPC UA
specifications:

Further Informationwww.opcfoundation.org➞ OPC UA Technology➞ OPC Foundation➞ Case Studies➞ Certified Product List
➞ Vendor List
➞ Product Search➞ Member List
➞ Member Press Releases➞ Member Login Area
➞ Newsletters and Articles➞ Blogs➞ Upcoming Events➞	Downloads(White papers, specifications, sample code, test
tools, …)➞	Regional Area
(Europe, Japan, China)➞ Videos➞ Webinar Recordings➞ IP Policy➞ Support Area
➞ Careers

MEMBERSHIP INFORMATION➞ 1. Core Specifications:	Contains the basic concepts of UA technology
and the security model, and contains abstract
description of UA meta model and UA services,
also contains the concrete UA information modeland protocol mappings, plus the concept of profiles for scalability➞ 2. Access Type Specifications:	Contains the information model extension for the
typical UA access types DA, A&C, HA and Programs➞ 3. Utility Type Specifications:	Contains additional concepts for finding UA enabled components and endpoints in and acrossnetworks, and contains the description for aggregates and calculation methods to be applied on
historical values

IEC 62541 Standard – Every OPC UA core specificationis also available as open IEC 62541 standard.

V1.1 GB

V1.1 GBOPC FOUNDATION – www.OPCfOUndAtiOn.Org

OPC FOUNDATION – www.OPCfOUndAtiOn.Org

Becoming an OPC Foundation Member is more than just easy! Membership provides
the best way to stay up-to-date with technology and to reach the community most interested in the value and benefits of OPC. With membership comes privileges …

Why Join the OPC Foundation?

Get Full Access to the
OPC Specifications➞ OPC is the interoperability standard for
secure, reliable and platform-independent
information exchange. The OPC specifications define the interface between clientsand servers, as well as servers and servers,
for different fields of applications, including access to real-time data, monitoringof alarms and events, access to historical
data and other applications.
As an OPC Foundation corporate member, you get complete and early access to
the OPC specifications before the generalpublic. You can even join working groups
and engage in the development of ongoing
specifications.
Get hands on Tools that
support your development➞ OPC Foundation corporate members
can use and redistribute the OPC Foundation deliverables, common components,
communication stacks and shared applications. Members also have access to the
OPC Compliance Test Tools (CTTs) to ensure your OPC products meet the appropriate specifications.
Corporate members can list OPCcompliant products in the interactive OPC
Product Guide on the OPC Foundation
web site at www.opcfoundation.org
Certify Your Products for Compliance➞ OPC members can participate in IOP

workshops and test their products for interoperability. Annual events are hosted inyour geographical region in Europe, North
America and Japan. OPC Foundation(OPCF) corporate members can add extra
value to their product by applying for thehighest quality logo awarded by the OPCF.
The OPCF certifies products in independent test facilities in Europe and in North
America. (See reverse side for a full explanationof corporate membership classes.)

Why certify? Objective certification testing by the independent test lab guarantees
that your products comply with the OPC
specifications, interoperate with third-party
products, and have passed reliability, usability and robustness testing.
Connect with the OPC Community➞ With almost 500 member companies,
the OPC Foundation is the world’s leading community for interoperability solutions
based on the OPC specifications.
All OPC Foundation members—including corporate, end-user and non-voting
members—can proudly display the OPC
Foundation logo and the OPC Foundation Member logo. For the OPC technology suppliers, the OPC Foundation offers
a complete marketing program, including
a newsletter, web site and educational
events. For the OPC end-user community,
membership offers you the chance to collaborate with the OPC developer community to build best-in-class solutions. ■THE OPC FOUNDATION IS … COMMUNITY:➞ The world’s leading community

Open

OPC Unified Architecture –Advantages and possibilities of use
for manufacturers and users ofautomation, IT or MES products
OPC UA➞ OPC Unified Architecture is the
new technology generation of the
OPC Foundation for the secure,reliable and vendor-neutral transport of raw data and pre-processed information from the manufacturing level into the production
planning or ERP system. WithOPC UA, all desired information isavailable to every authorised application and every authorised person at any time and in any place.
This function is independent of the
manufacturer from which the applications originate, the programming language in which they weredeveloped or the operating system

WHY JOIN THE OPC FOUNDATION (OPCF)?

1. Obtain full access to new OPC Specification
Release Candidates and latest technology
enhancements as well as new features.
2. Actively participate in Working Groups, drive
technology forward and influence the technology with your requirements, ideas andknow how.
3. Get free use of OPCF test tools that support
you in development of high quality products
and speed up development and testing.

on which they are used. OPC UA
supplements the existing OPC
industry standard by importantcharacteristics such as platform
independence, scalability, highavailability and Internet capability.
OPC UA is no longer based on
DCOM, but has been conceived
on the basis of a service-oriented
architecture (SOA). OPC UA cantherefore be ported very easily.
Today, OPC UA already forms
the bridge between the Enterpriselevel down to embedded automation components – independent ofMicrosoft-, UNIX- or other operating systems. ■

–
–
–
–

Standardised
communication
via internet andvia firewalls
OPC UA uses an➞optimized TCP-based UA
binary protocol for data exchange; Web Services andHTTP are additionally supported. It is sufficient toopen up just a single port ina firewall. Integrated security mechanisms ensure secure communication via theInternet.

4. Certify products at an accredited, independent Certification Lab in your region. Certification logo adds substantial value to your product and is demanded in many open tenders.
5. Participate in promotion and marketing
events, get your company and productshown on exhibitions, road shows andevents, get your company profile and products listed on the OPCF website.

OPC Unified Architecture – Standardised communication
PrOtECtiOn AgAinSt UnAUtHOriSEd
dAtA ACCESS➞ The OPC UA technology uses a mature security
concept to ensure protection against unauthorised
access or sabotage of process data and as wellagainst errors due to careless operation. The OPC
UA security concept is based on World Wide Web
standards and encompasses options for user authentication, the signing of messages and the encryption of the transmitted user data.

7. Connect with the OPC developer and user
community.

COLLABORATION:➞ The official source for the➞ The collaboration with other or-for interoperability solutions based

OPC Certification Program, ensur-

ganizations advances the adoption

on OPC specifications that delivering OPC products plug and play inand use cases of OPC based

universal connectivity.

real-world applications.

products.

OPC Foundation
MembershipBenefits

dAtA SECUrity And rELiABiLity➞ OPC UA defines a robust architecture with reliablecommunication mechanisms, configurable timeouts,
automatic error detection and recovery mechanisms.
The communication connections between OPC UA
clients and servers can be monitored. OPC UA offers
redundancy features that can be applied to serverand client applications to prevent loss of data and to
implement highly available systems. ■OPC Unified Architecture
Secure communication with IEC 62541 OPC UA

–
–
–
–

> 450 members
Platform-neutral
All areas of application
All connections

Productivity

Collaboration
–
–
–
–
–
–
–
–

Device Integration
IEC 61131-3 / PLCopen
Analyzer Device Integration
ISA-95, ISA-88
MTConnect
Smard Grid
Field Device Integration
EDDL and FDT

AddrESS:OPC Foundation
16101 N. 82nd Street
Suite 3B
Scottsdale, AZ 85260-1868
USA

OVErViEw Of OPC UA➞ OPC Unified Architecture (OPC UA) is the newtechnology generation of the OPC Foundation
for the secure, reliable and manufacturer-neutraltransport of raw data and pre-processed information from the manufacturing level into the production planning or ERP system.
With OPC UA, all desired information is available
to every authorised application and every authorised person at any time and in any place. Thisfunction is independent of the manufacturer fromwhich the applications originate, the programming language in which they were developed or
the operating system on which they are used.
On the basis of a service-orientated architecture(SOA), OPC UA forms the bridge between thecompany management level and embedded automation components. ■COntACt:

Secure concepts

Phone: (1) 480 483-6644
Fax: (1) 480 483-7202
office@opcfoundation.org

Security was a central requirement in the development of OPC UA. it is addressed in various areas:

www.opcfoundation.org

SECUrity➞ X509 certificates➞ OpenSSL encryption➞ User / password➞ Access rights for each
attribute

OPC UA
Overview

AUtHEntiCAtiOn And AUtHOriSAtiOn Of
USErS➞ On establishing a connection, the user identifies
himself via• X.509 certificates• User name / password• or Kerberos
Thus all common user administration systems suchas Microsoft Active Directory are supported.
Furthermore, the access rights (for example for thereading and writing of values) can be specified in afine-grained manner per user.

V1.1 GBOPC FOUNDATION – www.OPCfOUndAtiOn.Org

Open

–
–
–
–

Industry standard
Manufacturer-independent
Interoperability
Reliability

infOrMAtiOn:

6. Participate in Interoperability Workshops(IOP) and test your product against others.

COMPLIANCE:> 450 members
Platform-neutral
All areas of application
All connections

Productivity––––

Industry standard
Manufacturer-independent
Interoperability
Reliability

Collaboration
–
–
–
–
–
–
–
–

Device Integration
IEC 61131-3 / PLCopen
Analyzer Device Integration
ISA-95, ISA-88
MTConnect
Smard Grid
Field Device Integration
EDDL and FDT

AddrESS:OPC Foundation
16101 N. 82nd Street
Suite 3B
Scottsdale, AZ 85260-1868
USA

Open

Manufacturer-specific extensions

Information models ofother organisations
DA

AC

HA

Prog

Security

Phone: (1) 480 483-6644
Fax: (1) 480 483-7202
office@opcfoundation.org
infOrMAtiOn:

www.opcfoundation.org

–
–
–
–

> 450 members
Platform-neutral
All areas of application
All connections

Cooperation of OPC Foundation and PLCopen
Interoperability of the new generation

can also be described completely
with OPC UA. The object-oriented
rules according to which the address space of an OPC UA serveris structured and the OPC UA interface for accessing it are thereby
kept so general that OPC UA canbe regarded as a network-capable programming language. OPC
UA only becomes specialised forautomation technology throughspecific information models suchas Data Access, Alarms & Conditions, Historical Access and Programs. For these information models, there is no longer any need toextend the basis and the protocols
or the programming interfaces. ■Cooperation with otherstandardisation organisations was importantfor OPC UA from the
beginningThis simple extensibility by information models makes OPC
UA very interesting for otherstandardisation organisations.
They only have to define which
information is to be exchanged,
but no longer how the information must be exchanged. Before the start of the OPC UA
specification, this was one of
the most important requirements that OPC UA as a universal communication platform
and IEC standard can form abasis for other standards.

–
–
–
–

Industry standard
Manufacturer-independent
Interoperability
Reliability

HOw ArE COMPAniOn SPECifiCAtiOnSCrEAtEd?
➞ OPC UA Companion Specifications are developed in various ways. One possibility is a working

–
–
–
–

> 450 members
Platform-neutral
All areas of application
All connections

Collaboration
–
–
–
–
–
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Device Integration
IEC 61131-3 / PLCopen
Analyzer Device Integration
ISA-95, ISA-88
MTConnect
Smard Grid
Field Device Integration
EDDL and FDT

AddrESS:OPC Foundation
16101 N. 82nd Street
Suite 3B
Scottsdale, AZ 85260-1868
USA

Productivity➞ OPC Foundation and PLCopen have combined their technologies to form one platform andmanufacturer-independent information and communication architecture. The mix of OPC Unified
Architecture (UA) and IEC 61131-3 is thus the
future-safe basis for the realisation of automation
tasks.
The objective is to increase the reusability of controller- and visualisation modules and their communication and thus to considerably increase efficiency in the engineering process.
OPC UA fOr iEC 61131-3 (PLCOPEn)
The IEC 61131-3 standard defines various programming languages and a software model forthe programming of control systems. The implementation of this IEC61131-3 software model onan OPC UA server address space is defined in
the common specification adopted by both organisations.
Thus corresponding OPC UA object types are
created from declarations of function blocks in
the PLC and corresponding OPC UA objects
from instances of the function blocks.
BEnEfitS
This results in the advantage that a control program, regardless of the controller on which it isexecuted and the OPC UA server via which thedata is accessed, is always implemented in thesame structure of objects in the address area. For
UA clients, this results in always identical UA access at the semantic level. ■group of OPC members within the OPC Foundation
which defines an information model for special
branches of industry or areas of application.
The specification OPC UA for Analyzer Devices (ADI)
was created in this way on the basis of customer
requirements. Another possibility is a common working group with one or more other organisations withthe objective of defining an OPC UA information
model for a standard outside the OPC Foundation.
The information model OPC UA for IEC 61131-3 wascreated in this way with PLCopen. ■Phone: (1) 480 483-6644
Fax: (1) 480 483-7202
office@opcfoundation.org

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Industry standard
Manufacturer-independent
Interoperability
Reliability

Collaboration
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Device Integration
IEC 61131-3 / PLCopen
Analyzer Device Integration
ISA-95, ISA-88
MTConnect
Smard Grid
Field Device Integration
EDDL and FDT

AddrESS:OPC Foundation
16101 N. 82nd Street
Suite 3B
Scottsdale, AZ 85260-1868
USA

COntACt:

OPC UA – Standardised communication acc. to IEC 62541
OPC UnifiEd ArCHitECtUrE COMPAniOn
SPECifiCAtiOnS➞ OPC UA consists of a list of specifications for thebasic functions and the information models basedon them, such as Data Access and Alarms & Conditions. Specifications that define further information
models beyond that are called Companion Specifications.

Open

Base services of OPC UA

Productivity➞ OPC Unified Architecture brings
two elementary innovations into
the OPC world. On the one hand,
the Microsoft Windows-specific protocol DCOM is replacedby open, platform-independent
protocols with integrated security mechanisms. On the other,
the proven OPC features, suchas Data Access, Alarms & Eventsand Historical Data Access, aresummarised in an object-oriented
model and supplemented by new
and powerful features, such as
methods and type systems. As aresult, not only can the OPC interface be directly integrated into systems on arbitrary platforms withdifferent programming languages,
but arbitrary complex systems

COntACt:

intEgrity➞ The signing of messages prevents a third party
from changing the contents of a message.
This prevents, for example, a write statement toopen a switch being falsified by a third party and theswitch being closed instead.

V1.1 GBOPC FOUNDATION – www.OPCfOUndAtiOn.Org

OPC Unified Architecture –The universal communication platform
for standardised information models

COntACt:

OPC UA – interoperability at the semantic level
COMPAniES PArtiCiPAting
in tHE SPECifiCAtiOn

COMPAniES PArtiCiPAting
in tHE dEMO

Phone: (1) 480 483-6644
Fax: (1) 480 483-7202
office@opcfoundation.org

infOrMAtiOn:

infOrMAtiOn:

www.opcfoundation.org

www.opcfoundation.org

ALrEAdy AVAiLABLE
COMPAniOn
SPECifiCAtiOnS➞ OPC UA for Devices➞ OPC UA for Analyzer Devices➞ OPC UA for IEC 61131-3

Collaboration
Overview

Collaboration
PLCopenAll flyers are available in English, German, French, Spanish, Italian.

Recomended Literature
OPC
From Data Access to
Unified Architecture

OPC
UnifiedArchitectureISBN 978-3-8007-3217-3

ISBN: 978-3-5406-8898-3

28

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

www.opcfoundation.org