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Process Engineering
Increased acceptance of standardization
Whether you are looking at pumps, analytical
instruments or dosing devices, process engineering without electronic
components is virtually inconceivable. These components increase
efficiency and effectiveness, ensure a high level of quality, and make a
significant contribution to safety and environmental protection. This
makes it all the more important for process engineers to know what is
technically feasible.
Although several projects have been placed on the back burner in Europe
in recent years, particularly in the chemical industry, automation in
the process engineering sector provides the only way in the medium term
of delivering more effective and efficient processes. To this aim,
technology has to be borrowed from other industries. At the end of the
day, most large corporations have imposed strict cost controls at their
production facilities. There could be no great success stories without
automation or the appropriate measurement and control equipment. The
linkages between company management and field devices, between
e-business and engineering, between maintenance and process optimization
are becoming increasingly more complex. Many of these areas of endeavor
have their own software solutions, which have a large number of
interfaces that need to be connected together. It comes as no surprise
that although hardware is still sold in the automation industry, it only
makes up one third of turnover. Services and software are the main
element in the contract awards.
Expectations and reality
Open designs already offer the customer supplier independence, and
networked systems increase flexibility, productivity and efficiency in
the process industry. Low-cost, flexible operating and monitoring
systems are examples of this technology, which make it easier for users
to operate their equipment, thus increasing production reliability. The
reality, however, often looks quite different. There are still a lot of
insular solutions, which are used for the most diverse tasks within a
company. This begins with the planning process. More and more frequently,
interfaces need to be taken into account between process optimization
solutions, CAE (Computer Aided Engineering) systems, and material
management systems. Yet a large portion of the documentation is still
paper-based, to say nothing of the numerous special solutions that
undoubtedly have existed for years in every company. There is a good
reason for having them, but they tend to be unsuitable for maintaining a
continuous workflow.
There is a general recognition that information and data about a system
and its environment are more valuable than the system itself. Much has
been done by equipment manufacturers and system suppliers in the field
of asset management. Asset management means enhancing the value of a
system by operating the system in the best way possible. Maintenance in
the future will no longer be aimed exclusively at maximum or optimum
availability of components and systems, but rather at the required level
of reliability. Digital measurement instruments provide a valuable
source of data and hence information about the actual state of
individual components. The question remains, however, of how to process
the data in a way that benefits the system operator without simply
creating even more work. At the moment, the user is often confronted
with a large amount of superfluous, redundant data, to say nothing of
the immense scope of the interfaces required. There is good reason why
data consistency and data management are among the ongoing hot topics in
discussions on requirements in the measurement and automation
engineering industry.
Field devices
Field devices, which have been underestimated for a long time, play a
special role in these discussions and create the basis for successful
asset management. The prospects are good for fieldbus and control
systems, and the long-term future for the various field devices is not
looking too bad either. Regardless of the measurement principle used,
mechanical devices are losing ground to digital devices, yet mechanical
components will certainly not disappear altogether. They have the big
advantage that their measurement principle is well known, and they have
been working reliably for a long time. Sensors must be reliable as well
as accurate. Digital technology delivers fast, high-precision
measurement, but electronics are often susceptible to conditions that
exist in the harsh everyday process environment. Many devices have also
been overloaded with functionality during the course of the
digitalization process. This can delay start-up and carries with it the
risk of operator error.
Device manufacturers have recognized the challenges and are working on
features such as a uniform data format, homogenous interfaces or
improved maintenance capability. Once these challenges have been met,
information from field devices will facilitate preventive maintenance
and successful asset management.
In general, the question of how to integrate the intelligence of field
devices into other systems remains open. Because attention is shifting
from the individual device to the entire instrumentation package, there
is an urgent need for measurement instruments that are compatible with
and communicate with each other. It is not unusual for hundreds of field
devices from various manufacturers to be installed on a system.
Configuration and parameter setting still have to be performed for every
device, and the specific device parameters must be recorded and
transmitted to the control system. Manufacturers do supply the required
tools, but learning how to use them is not a trivial task, and it is
necessary to convert large amounts of data. There is still no real
continuous flow of data. Instead, users are faced with growing costs for
documentation, consistency checking and configuration on a daily basis.
Ethernet and Fieldbus
The impression was often created in recent years that the important of
Fieldbus was declining in favor in Ethernet. This will certainly not be
the case, and Fieldbus systems will continue to be indispensable in the
future. Ethernet will, however, penetrate further at the field level and
will be used for applications such as intelligent field devices. A study
conducted by Frost & Sullivan predicts that the European Fieldbus market
will grow from $US 170 million in 2001 to $US 420 million in 2008.
High investment costs, a lack of standardization and insufficient
compatibility with other equipment act as impediments to a more
widespread introduction of Fieldbus systems. The reluctance to make new
investments also has a negative impact on Fieldbus. Where Fieldbus has
already been installed into new systems, these systems have generated
real cost savings. Operators are very satisfied with their systems.
Fieldbus systems are indisputably the key technology for asset
management. Despite user interest in a common specification independent
of any manufacturer, there is still no uniform Fieldbus standard. The
pragmatic view is now being taken that there will simply be different
bus systems for different applications. It is good news for the user
that manufacturers are increasingly trying to produce open systems, and
there is increased cooperation with user organizations.
The experts agree on one thing: there is a need for standards that apply
to field communication protocols, software and Fieldbus devices. The OPC
DX interface (OLE for Process Control Data Exchange) brings continuous,
uniform data communications in mixed automation solutions one step
closer. The intent is to enable cross-manufacturer data exchange between
servers from different manufacturers using Ethernet networks. Companies
have now announced initial prototypes that offer OPC DX functionality.
Longer Life Cycles
Among the other problems that now confront the industry is the fact that
life cycles vary greatly from one product to another. To cite one
example, a control system often runs for 10 or 20 years to the full
satisfaction of its operator, but semi-annual release cycles for a
software product are not uncommon. Only visionaries could have suspected
15 years ago how important Internet technology would become for
automation. Now, however, the Internet language XML (Extension Markup
Language) has become the basis for modern data exchange. The challenge
in the future will be to create a link between these two worlds.
One thing is certain: the impact of Internet technologies will extend
into traditional fields of automation engineering. Web technology will
open the door to mobile data communications in the world of automation.
The current approach to opportunities offered by the Internet remains
cautiously optimistic. On the one hand, web technologies are suitable
for widespread use, because nearly all the data are available on every
PC. There is no need for special application programs, which are often
difficult to operate, to perform a simple exchange of information.
Diagnosis via the Internet also offers very interesting opportunities,
for example the integration of video images. However, it is important to
ensure that the information can be transferred reliably on the Internet,
and that is not always the case today. Even when there is no need for
real-time data transfer, the Internet is currently not a suitable
solution.
A slow transition
Whatever form process automation may take in the future, the rational
use of information appears to be what is currently needed. There is
simply no demand for data at any cost. A mountain of information does
not help anyone operating a system. Operators merely need to decide
whether they should shut down equipment or not in case an alarm is
raised. Service technicians, on the other hand, can make good use of
selected information.
Control system manufacturers and device suppliers will face a growing
list of tasks to address in the coming years. Because technical
complexity continues to increase, maintenance and service will play a
dominant role in device technology in the future. Many devices are still
a long way away from offering plug & play functionality, despite the
fact that simple operation is high up on the user priority list. Today
more than ever, very solid know-how is essential to really make use of
new functionality and integrate the devices into existing systems. This
applies both to the manufacturer and the user.
There must be a realistic timeframe for the transition from the analog
to the digital world. Old and new systems will have to coexist, and
manufacturers must respond to this reality. They must also take account
of the fact that structures in companies will change as a result of
mergers and spin-offs. Small companies prefer solutions from a single
source, whereas large corporations are familiar with using various
versions at different locations. <<
Source: Dechema
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