February 2014
30
E
XHIBITION
H
IGHLIGHTS
OPC Unified Architecture (UA) is the OPC
Foundation’s next generation of OPC standards.
Learning from past successes and challenges
as well as the evolved needs of modern control
automation environments, the OPC Founda-
tion has stayed true to the original vendor-
neutral data connectivity philosophy but has
redefined and upgraded the flexibility, power,
and security of the entire OPC model. Rapidly
gaining traction in many industrial spaces out-
side of process control (e.g. building automa-
tion), OPC UA was designed from the ground
up to be platform- and OS-independent, en-
abling seamless communication between all
components of an automation system and the
enterprise.
Thanks to OPC UA flexibility, OPC UA appli-
cations can be developed for non-Windows
platforms such as Linux and for embedded
systems running an RTOS (Real Time Oper-
ating System), or even for so-called bare
metal environments where there is no oper-
ating system. OPC UA can be embedded in
microcontrollers costing less than $5. Why
embed an OPC UA server in a device? In a
word: simplicity. For end users, the Holy
Grail of data connectivity is finding the easiest,
most efficient and cost-effective way to access
their data when and where they need it – all
without adding additional PCs and perform-
ing additional configurations and mainte-
nance. Having OPC UA run natively (embed-
ded) right on the devices themselves makes
good sense.
If you have embedded an OPC Server directly
in the device you can create an optimal solution
for almost every application. Because the OPC
tags are natively present in the device, the
commissioning engineer simply has to point
and click to choose the OPC tags he wants to
visualize or log. Because the network is using
OPC from end to end there is no need to man-
ually create OPC tags and map process variables
from other protocols. This greatly reduces
commissioning time and reduces the potential
for error. Because OPC UA communications
can be authenticated and encrypted, the in-
stallation has the potential to be more difficult
for an attacker to compromise. Simply getting
inside the network boundary is not sufficient
to carry out an attack on a process.
While the data from embedded UA servers
would typically be routed via a central server
or redundant servers, there is always the option
to connect to the device directly if required.
This provides many options for device config-
uration and management as well as cost re-
ductions for very small installations. Finally,
OPC UA is more than an industrial automation
protocol. It also contains an extensible infor-
mation model that makes it very attractive to
many vertical markets. Adding OPC UA
support to your device offers the potential to
open up new markets.
An example for this is the company Areva.
They recognized early on the potential of OPC
UA in sensors and started integrating them
into monitoring instruments (SIPLUG) for
valves and their associated electric drives. The
solution is used in the nuclear industry for
monitoring critical systems in remote envi-
ronments, 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 inte-
gration into existing facility infrastructures
was difficult, and the outlay for various aspects,
such as data buffering or data analyses, was al-
ways linked with extra costs.
From an end-user perspective, the native OPC
UA connectivity enables direct embedding of
Areva products into the infrastructure, without
the need for any additional components: The
solution allows the reporting and trend moni-
toring system of Areva to access the SIPLUG
data directly. This means that the need for ad-
ditional drivers and infrastructures can be dis-
pensed with completely. What’s more, addi-
tional values, such as pressure and temperature
values available at the factory level, can be
End-to-end data access with
embedded OPC Unified Architecture
By Liam Power,
MatrikonOPC
Embedded OPC Unified
Architecture (UA) offers
native open data connectivity
that is more secure, easier
to integrate in multi-vendor
environments, and opens doors
to new markets, as
demonstrated by AREVA.
Figure 1. Embedded OPC UA
connectivity
