Advancements in fieldbus controlled valve automation has been driven
by the need to reduce costs, operator intervention and footprint on
the field. The ability to control and manage processes has increased
to a great extent where field devices can execute process control
loops. In comparison to the analogue transmission system the fieldbus
system involves reduced cabling and higher data transmission rates
resulting in more information transmitted over the network.

Process industries are adopting fieldbus networks for the enhancement
of plant control and operation. The adoption of fieldbus systems is
happening on an increasing scale due to reduction of wiring costs and
diagnostic features that come along with fieldbus systems. Due to
these factors process industries have achieved increased return of
investment.

A general challenge in the fieldbus market is the fact that fieldbus
systems are selected based on the credentials of the company rather
than performance of the fieldbus communication system. Major
automation companies market field devices with fieldbus systems
developed by them. The lack of early standardization has contributed
to the development of individual fieldbus protocols by the major
process automation companies.

“Intelligent field devices have created a revolution in the way
machinery, process equipment and plants are being managed. Field
devices transmit a wide range of self-diagnostic information that can
be used to monitor their health,” says Frost & Sullivan Technical
Insights Research Analyst Vishnu Sivadevan.” This means that the
technological advancements in the development of ‘intelligent’ field
devices such as intelligent positioners and actuators are towards
incorporation of features that enable real-time monitoring and
diagnostics.”

The major challenge for upgrading a plant to fieldbus technology is
the operator training aspect. The personnel at the process
installation are usually trained for the existing industrial network.
An upgrade or an expansion of the existing industrial network with
fieldbus technology creates a situation where personnel have to be
trained for two networking protocols. Due to the time that may elapse
for operator learning and its effect on total installation time, the
industry is adopting a cautious approach for upgrades to fieldbus
systems.

“End users are only beginning to realize the true potential of
diagnostic capabilities of intelligent field devices,” says Sivadevan.
“A large section of process industries still function on analog
industrial networks that are not capable of transmitting information
other than control signals. In cases where industrial communication
systems have been upgraded to fieldbus systems, full utilization of
historic and real-time diagnostic information has not been achieved.
Technical advantages of fieldbus and significant maintenance cost
reductions where fieldbus automation has been implemented are
convincing reasons for industries to go for upgrades.”

Smart field devices such as valve positioners are indispensable to
attain and maintain optimum performance in process control. Proactive
planning of maintenance is possible due to the diagnostics and
predictive maintenance functions that are ubiquitous in most smart
devices.