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How Do You View Future Developments
Towards Achieving a Global Protocol?
I think it will take a while until all parties involved really agree on one
protocol which can be used universally and also enables connection
to cloud solutions, for example. A publish/subscribe mechanism, as is
commonly found in message-based systems, is currently in develop-
ment for OPC UA. In addition, OPC UA is not yet suitable for hard real-
time applications, because no determinacy is given by the underlying
TCP/IP. Concepts for the expansion of the transport layer accordingly,
for example, through TSN (time-sensitive networking), already exist,
so it can be expected that such expansions will find their way into the
standardization of OPC UA in the near future. A universal protocol is
essential, especially from a global networking perspective – otherwise
production processes will only ever be able to communicate within
companies and countries. With its standardized data model, OPC UA
is very well-positioned in the race for first place. We should use the
current lead to establish OPC UA as a protocol through which each
element can communicate with all the others; after all, that is the core
enabler of Industry 4.0.
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Dr. Jörg Nagel, Senior Expert on Industry 4.0 –
Industrial Internet Solutions at Pepperl+Fuchs
What Are the Advantages of OPC UA
Compared to OPC Classic?
OPC UA is a successor protocol that delves much deeper and offers
functionalities of which OPC Classic is not yet capable. For example,
OPC UA is independent of any platform. However, the key advantage
offered by OPC UA that makes it very interesting in terms of achieving a
communication system within the scope of Industry 4.0 is the universal
data model. What was previously determined by the application devel-
oper with OPC Classic is now standardized and independent of any
particular manufacturer.
Thanks to the service-oriented architecture of OPC UA, any information
technology system can access the data sources in the field. No special
communication paths need to be maintained for the integration; simple
network access is enough. As a result, a device with an OPC UA
server can easily be integrated into existing systems.
Why Is OPC UA Particularly Suitable
as a Standardized Protocol for Industry 4.0?
OPC UA can do more than just “transport” data from A to B. The actual
transport layer is supplemented by a semantic data model, which
enables semantic interoperability between all communication partners.
From the field level and intelligent sensors, for example, it is not only
the actual measured values (process data) that are forwarded, but
information about the form, importance, context, and structure of the
data as well. The sensors can be accessed directly via OPC UA from
the IT level. The simple interpretation of the data is ensured by a kind
of “self-assessment” of the sensor, which details its abilities.
Three Questions to …
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