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Markets + Trends
| News for Process Automation 1/2016
OPC UA as Standard
Plattform Industrie 4.0 advocates OPC UA – UA stands for Unified
Architecture (IEC 62541) – as a standard protocol. The communication
standard enables data to be exchanged between all levels of a
company and the connected world outside of the company. OPC UA
includes various transport layers, as well as a semantic data model to
ensure the meaningful display of information. In addition to the clearly
specified semantic data models, OPC UA also features mechanisms
for storing and providing historical data, for signaling events, and for
executing functions on the server. OPC UA is an open standard,
independent of any particular manufacturer. When using OPC UA in
productive systems, one key factor is that each device that makes
its functionality available via an integrated OPC UA server can provide
a kind of self-assessment to other communication partners. This
eliminates the need for the usual distribution of description files, such
as IODD or GSD files, via a separate channel. Instead, when a client
accesses the server, all properties are immediately available in a sorted,
searchable tree.
By using discovery servers, the properties of registered devices can
be searched before the connection is established. The discovery
server also provides the requesting entity with information on how the
relevant device, such as a sensor, can be reached via the network.
An integrated security and authentication concept ensures the secure
exchange of data between communication partners in OPC UA. If the
corresponding access authorizations are available, OPC UA enables
the seamless and universal exchange of information across all levels
of an organization and its borders. Given the three-dimensional RAMI,
this means that OPC UA can be unified with all layers and aspects
of RAMI.
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