V1.1 GB

OPC FOUNDATION – www.opcfoundation.org

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

Open

Manufacturer-specific extensions

Information models ofother organisations
DAAC

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

Base services of OPC UAProductivity➞ 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

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 thebeginning––––This 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.

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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
USACONTACT:OPC UA – Standardised communication acc. to IEC 62541
OPC UNIFIED ARCHITECTURE COMPANIONSPECIFICATIONS➞ 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.
HOW ARE COMPANION SPECIFICATIONSCREATED?
➞ 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.
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
INFORMATION:

www.opcfoundation.org

ALREADY AVAILABLE
Companion
SpeCifiCationS➞ OPC UA for Devices➞ OPC UA for Analyzer Devices➞ OPC UA for IEC 61131-3

COOPERATION:➞ PLCopen➞ ISA➞ MTConnect
➞ FDT
➞ PNO
➞ HART➞ FFOPC UA FOR DEVICES (DI)
➞ A generally accepted model for the configuration of hardware and software components wascreated in the common working group of OPC
Foundation, Profibus User Organisation (PNO),HART Foundation, Fieldbus Foundation (FF) andField Device Tool (FDT) for the standardised configuration of field devices. This base model wasreleased by the OPC Foundation as an independent information model and also serves as thebasis for further standards such as OPC UA forAnalyzer Devices and OPC UA for IEC 611313. The information model defines basetypes forconfigurable components and devices; it definesconcepts for the logical grouping of parameters,
methods and components and it defines pointsof entry in the OPC UA server address space.
Besides that, information for the identification ofdevices and the available protocols is defined. An
initial version of this specification has been available since the end of 2009. ■Extended options despite simplified interface –new OPC UA communication is applied in existing andnew standards
OPC UA FOR ANALYZER DEVICES (ADI➞ This specification defines an information model forcomplex devices for process analyzer, for example
gas chromatography. Apart from the various components of such a device, parameters for configuration and typical state machines are standardised.
The ADI specification was created at the suggestionof the users of process analysis devices in order tosimplify integration into automation systems. TheADI specification uses the OPC UA DI model as abasis.
OPC UA for IEC 61131-3 (PLCopen)➞ The IEC 61131-3 standard defines various programming languages and a software model for theprogramming of control systems. The implementation of this software model on an OPC UA server
address space is defined in the specification. Thus,
corresponding OPC UA object types are createdfrom declarations of function blocks in the PLC andcorresponding OPC UA objects from instances ofthe function blocks. This results in the advantagethat 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.

Field Device Integration (FDI)➞ Two standards are used today for the configuration of field devices. Electronic Device DescriptionLanguage (EDDL) works according to the principlethat the configuration parameters of a field device aredefined by a description file and that the configuration takes place on this basis. Field Device Tool (FDT)
works according to the principle that the equipment
manufacturer provides a software component for ageneral configuration tool with the device. Both standards are to be merged in the future via the common
FDI standard using OPC UA.
In FDI, a field device is to be described via a socalled Device Package. These consist of a generalparameter description and user interface elements.
The configuration server is thereby an OPC UA server that fills its address space on the basis of the Device Packages, and the configuration interfaces areOPC UA clients that access the equipment parameters via OPC UA and use specific user interface elements from the Device Packages for the display. ■OPC UA – interoperability at the semantic level
ISA-95 AND ISA-88➞ The two ISA standards define information models
for production control systems for batches and MES.
Mapping to OPC UA is planned.
MORE INFORMATION

www.opcfoundation.org

Smart Grid➞ There are various standards in the field of power
generation and power distribution and new standards are being created for smart grid networks. In

this field, various mappings of existing standards toOPC UA or the direct use of OPC UA in new standards are under discussion.
MTConnect➞ MTConnect defines standards for the provision ofmachine data. Mappings of these data descriptions
to an OPC UA information model are to be defined ina common working group. ■