Realizing the Promise of Wireless
Reprinted with permission from CEP (Chemical Engineering Progress), May 2009.
Copyright © 2009 American Institute of Chemical Engineers (AIChE).
Instrumentation
Realizing the Promise
of Wireless
Peter Zornio
Bob Karschnia
Emerson Process Management
Innovation drives the growth of wireless technology,
as successful applications demonstrate
cost savings, reliability, safety, and ease of use.
R
eliable wireless communications systems are
removing the physical and economical barriers that
previously made it difficult or impossible to access
many types of information in chemical plants. In fact,
wireless automation technology addresses many management priorities, including continuous process improvement, safety, and protection of the environment, with such
dramatic ease and clear benefits that it is changing work
practices throughout the industry. The technology of transmitting never-before-available information from processes
and equipment can be put to use right now, regardless of
the vintage of the plant’s control system.
Wireless networks
Wireless technology includes both field networks and
plant networks integrated into an overall wireless plant
architecture (Figure 1).
A wireless field network is a group of devices capable
of measuring one or several process parameters and
transmitting information wirelessly to a single gateway,
or receiver. Many types of wireless field instruments are
available for measuring temperature, pressure, flow, level,
pH, vibration, discrete switch status, and valve position.
Typically, the gateway forwards the field-generated
data wirelessly to a control system via a native interface,
Modbus, or a similar connection, where wireless, analog
wired, and Foundation fieldbus data are combined. Two
key characteristics of wireless field networks are verylow-power radio transmissions, and adherence to process
industry requirements for timeliness, reliability, security
and accuracy. The low-power characteristic allows for
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CEP
nonrecharged battery-operated devices.
A wireless plant network implements Wi-Fi networking
using the IEEE 802.11 standard or other higher-bandwidth
network technology for communicating with mobile workers,
for tracking people and/or mobile assets, and for implementing wireless video. These applications are characterized by
their high bandwidth, use of devices that are rechargeable or
electrical-line powered and share applications bandwidth,
and transmission clarity and security.
Typical plant networks employ industrial-class mesh
IEEE 802.11 access points, a centralized network, and security management, including overseeing a series of wireless
local area network (WLAN) controllers, which are responsible for network-wide wireless functions. This provides a
cohesive wireless communications platform across the physical as well as the functional areas of plant operations, so that
the shared network can support diverse applications.
Chemical manufacturers can begin taking advantage
of wireless technology at the plant level and work down to
the field, or begin at the field level and work up. We have
found that starting at the field level yields quicker returns,
and this article focuses on those applications.
Standards for wireless field networks
The information technology (IT) community has
evolved the standards and practices now in use for plant
networks. However, the broader wireless community has
not provided a rigorous, well-tested and industry-accepted
standard suitable for wireless field sensor networks. Such
a standard should encompass robust industrial reliability
with very low power consumption for field measurement
Digital Automation System
Predictive Maintenance Software
Digital Automation System
Digital Controller
dP Flowmeter
Native
Interface
Foundation Fieldbus
Wireless
LAN
Controller
Smart
Wireless
Gateway
dP Level
Transmitter
WiFi
Access
Point
Video
Mesh WiFi
Network
pH/Conductivity
Analyzer
8-input
Temperature
Transmitter
Mobile Device
Digital Valve Controller
and Valve
Discrete
Transmitter
Vibration
Transmitter
pH Transmitter
Valve Position
Transmitter
High-Density
Measurement
Transmitter
Temperature Transmitter
S Figure 1. A wireless plant architecture integrates field and plant-wide applications networks. Processes and
equipment are monitored by WirelessHART devices in the field network, while operator mobility, people and asset
tracking, and video surveillance use Wi-Fi functionality at the plant level.
and control applications, and exhibit communications reliability approaching that of wired signals.
WirelessHART provides that, giving end-users the
promise of dependable wireless field-network instruments. These come from the member companies of the
industry-wide HART Communication Foundation (HCF)
that approved this standard in September 2007. WirelessHART products are now being shipped, and installations in chemical plants began during the latter part of
2008. See the sidebar on p. 24 for more information on the
WirelessHART standard.
The emergence of wireless field networks
Recognizable by their radio-frequency (RF) antennas
and absence of wiring, wireless transmitters (Figure 2) are
characterized by their low-power circuitry, onboard RF
transceivers with reliable and secure mesh communications, and long-life batteries.
The devices are represented the same as wired instruments on piping and instrumentation diagrams (P&IDs), and
S Figure 2. Wireless transmitters
are recognizable by their radiofrequency antennas and absence of
power wiring, which is replaced by
onboard long-life batteries.
operators do not see any differences in the data displayed by
wireless and wired instruments. The engineering, installation, and commissioning of wireless systems are, however,
much simpler. Furthermore, wiring drawings, cable tray
space, conduit or armored cable, tunneling, and scheduling
and performing installation are all minimized or eliminated.
Wireless instrumentation practices involve less planning, with easier and quicker installation and startup to
create the network. Attractive economics and ease of use
distinguish wireless technology from past process automation approaches, enabling engineers to unleash their creativity and imagination and do what previously was impossible.
Installation cost estimates for conventionally wired field
networks run from $50 to $100 per foot, depending on the
amount of engineering and construction required. Wireless
devices can save as much as 90% of the installed cost. As a
result, plant assets that were once prohibitively expensive to
monitor, such as remote tanks or pumps, manually operated
valves, safety showers, etc., can now be outfitted with
wireless transmitters to return data to the control room,
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23
Instrumentation
The Wireless HART Standard
There are clear reasons why WirelessHART is the one
standard needed to support the global deployment of
wireless technology for process field sensor networks.
WirelessHART enables reliable and secure communications based on channel hopping and self-organizing
mesh technology with end-to-end encryption, optimized
for low-power process applications, including control.
WirelessHART is easy for users to adopt, because
it is backwards-compatible with more than 26 million
installed HART devices, and it employs existing methods
of engineering, asset management, and host system
(DCS, PLC, etc.) integration. Thus, when configuring and
operating WirelessHART devices, users will see minimal
differences from their wired counterparts, and can even
retrofit existing wired devices with wireless communications for the purpose of transmitting additional information. This is critical to ensuring rapid and easy adoption.
WirelessHART is the only field network technology
recognized by formal standards committees. It is based
on the global standard IEEE 802.15.4 and approved
by the more than 210 HART Communication Foundation (HCF) members. It was also recently approved as a
Publicly Available Specification (PAS) by the International
Electrotechnical Commission (IEC) and is expected to become a global standard shortly. The International Society
of Automation (ISA) also has several committees working
on wireless standards for the process industries, including the wireless specification ISA100.11a, and the newer
WirelessHART convergence specification ISA100.12
focused on the process industries.
improving process reliability, safety and asset management.
Wireless is easy and simple to implement, requires
minimal engineering effort, and improves operational effectiveness. The number of times operators or maintenance
personnel must go into the field to gather information and
the amount of time needed to take corrective action can be
greatly reduced through structured or automated collection
of data from wireless transmitters.
The business advantages of wireless technology will lead
to continued growth. Last year, the Boston-based ARC Advisory Group, an industry research and consulting organization,
issued a five-year analysis and forecast called “Wireless for
Process Manufacturing,” saying, “The market for wireless
devices in the process manufacturing industries will grow at
an annual rate of 32% to reach $1.1 billion in 2012.”
Wireless or not?
Today, wireless is being used mainly for two application areas, and a third is on the horizon.
New, must-have measurements in existing plants. As new
environmental and safety laws are passed, many companies
are choosing wireless as the best, least-expensive way to
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May 2009 CEP
comply. These new, “must-have” measurements might be
required for storage tanks, pressure relief valves, or safety
showers — applications where wireless devices are easy to
install and can be put into operation almost immediately.
Want-to-have measurements in existing plants. The
second category, and by far the larger opportunity for
wireless, is the “want-to-have” measurement that could
not be economically justified previously. When a plant is
built, many proposed measurement points are never wired.
Later, operations and process supervisors invariably find
additional things they would like to measure in order to
improve plant performance, but installing new single-point
wiring is almost always cost-prohibitive. Cost-benefit
analyses show that many of those desired measurements
can now be had with wireless.
Perhaps the best example of “we’ve always wanted to
monitor them, but couldn’t cost-justify the instrumentation” are the many manually operated (and even some
automatic) valves that currently provide no feedback on
their actual positions. Yet, incorrectly positioned valves
represent a significant cause of safety-related incidents.
Infrequently used valves are not normally monitored
because the cost of wiring them is too high. However, wireless monitors are much more attractive, at only 10%–20% of
the cost of a wired solution. The advantages of monitoring
such valves may make this the largest application area for
wireless devices in chemical plants, at least in the near future.
Measurements in new plants that are normally handled
by wired instruments in today’s existing facilities. In addition to monitoring, wireless can be used for closed-loop
control. Current examples include applications such as
steam headers and remote tanks. Just about anything with
an acceptable long time constant for change can be controlled using wireless instrumentation currently available
on the market.
High-speed control is also possible, but the faster
device-sampling rates require the batteries to be changed
more frequently. As battery performance improves over
the coming years and confidence builds in the reliability
of wireless, its use for control purposes will become much
more commonplace.
As the performance of nonrechargeable batteries
improves, the potential exists for future plants to use wireless technology in critical monitoring situations where wired
instrumentation might normally be used. The most likely
scenario is that a small number of devices, for example, those
that are safety related, to be wired and the remaining devices
to be wireless. Wireless control systems will probably appear
first in major upgrades and greenfield plants.
User confidence in the reliability of wireless will be the
key factor that determines how quickly the technology will
be implemented. Some believe that wireless is inherently
less reliable than wired. This is not necessarily
true. Wired signals can be unreliable, especially where grounding is difficult, and in those
instances, wireless may be much more reliable.
The typical process plant’s “canyons of steel”
and moving obstacles, such as trucks and equipment, are also believed to cause problems for
wireless systems. This, however, is being overcome with advances such as time-synchronized
mesh protocols (TSMPs) in self-organizing
mesh RF networks, which have delivered wire- S Figure 3. Wireless monitors improve
the performance of filter systems.
less reliability exceeding 99% in numerous
applications around the world.
Wireless field network applications
The chemical industry’s interest in wireless instrumentation is reflected in the growing number of requests for
information related to this technology, and approximately
90% of those requests are for information on field networks. In addition to the monitoring of manually operated
valve position (as previously discussed), the following are
some common applications and real-world examples of
successful solutions.
Heat exchangers are often allowed to run until fouling adversely affects performance. Instruments are rarely
installed, even in newer plants. Wireless monitors give
plant personnel the advance warning they need to plan for
cleaning at the next regularly scheduled shutdown.
A major process company in Europe developed an
equipment health system for improving heat exchanger
maintenance. One of the company’s engineers explained,
“Wireless monitoring of heat exchangers enabled us to
determine which unit was the most fouled. This knowledge
let us compare the cost of cleaning with potential increases
in throughput to be gained, so our maintenance efforts
could be most productive.”
Filters normally run until they become clogged, but
their performance can be improved significantly and
energy consumption reduced by attaching wireless monitors to important filtering systems.
A European polyethylene maker uses wireless devices to
detect blocked filters and prevent production downtime at its
plant in Cologne, Germany (Figure 3). Finished polyethylene
pellets are transferred to a storage silo through pneumatic
conveying systems, and the incoming air is filtered to prevent
product contamination. When the hard-to-reach filters become
blocked, they lose efficiency, and the quality of the final product is reduced. Wireless differential-pressure meters enable
the maintenance team to determine which filters need cleaning
or replacement in order to minimize production disruptions.
Tanks pose a unique instrumentation problem, especially where dozens of vessels across a remote tank
farm need to be
monitored for level,
temperature, pressure,
S Figure 4. A self-organizing wireetc. Because of the cost of less network monitors 16 points on a
reaction tank at a fertilizer plant.
underground wiring over
the long distances involved,
such tanks are rarely instrumented, so a network of wireless devices provides an ideal solution.
In a phosphate fertilizer plant, a self-organizing mesh
network provides accurate minute-by-minute readings
from 16 pressure and temperature measurement points on
a reaction tank located about 250 ft from the central control
room (Figure 4). The remote tank is 40 ft tall and has four
different beds of gases that react with various process chemicals. Although not classified as a hazardous area, the tank
layout and distance involved made wiring both difficult and
expensive. According to a distributed control system (DCS)
specialist at the plant, “The self-organizing architecture was
the clincher for this application, and we already have plans
to add more devices to the established network.”
Pump and motor health need to be checked frequently
to warn of developing bearing problems that could shut
down a vital pump or motor, which in the worst-case
scenario would cause a very expensive process shutdown.
Wireless vibration monitors transmit data to software that
detects and pinpoints problems long before a failure, so
maintenance can be scheduled at a convenient time.
At one plant where it was difficult for personnel to
collect vibration data using portable instruments, an automated collection system was sought. The solution — wireless vibration transmitters plus a smart gateway — was
operational in just a few days. Accurate vibration data are
now available continuously, so personnel do not need to
enter the hazardous area to obtain the needed data.
Monitoring mobile assets, such as skids, pumps,
compressors, portable laboratories and test equipment, is
generally not possible with conventional wired instruments.
Wireless devices can be used to monitor various parameters
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25
Instrumentation
on mobile assets, even as
they are moved from one
place to another.
An international
specialty-chemicals manufacturer faced a problem of
monitoring temperatures in
railcars at its plant. The problem was solved by mounting
on each railcar a wireless
temperature transmitter that
sends continuous temperature readings to a central host
no matter where the car is
S Figure 5. Wireless transmitters
positioned at the site. Opera- monitor the returned-water temtors are made aware of any
peratures needed for environmental
unexpected temperature rise, compliance by a cellulose-fiber
and the company saves about producer.
$15,000/yr since workers no longer need to climb onto the
cars periodically to measure and record internal temperatures.
Environmental standards frequently specify that water
taken from a lake or river can be no more than one or two
degrees warmer when it is returned. Regulations often also
stipulate that a continuous record of water temperature at
both inlet and outlet points be maintained.
A cellulose-fiber producer in Europe employed wireless
temperature transmitters to monitor water temperatures
remotely (Figure 5), and avoided the cost of installing
a buried cable. “This technology was easy to install and
integrate in terms of data transfer,” said a company spokesman, “and the network has been 100% percent reliable.”
Rotating equipment and turbomachinery are commonly
monitored manually using a portable vibration data collector on a periodic basis. Wireless analyzers now do this
job continuously on rotating equipment such as turbines,
generator sets, reciprocating engines, compressors, and
other motor-driven machines. When pending problems are
diagnosed, technicians are generally able to fix them before
they become serious problems.
A specialty-chemicals manufacturer installed wireless
monitors on a large number of pressure, temperature, and
vibration points as a cost-saving measure. The network
includes several wireless vibration monitors on brine
centrifuges that had not been monitored in the past. In one
instance, analysis of the vibration data revealed a lubrication
deficiency that could have resulted in severe bearing damage, but the issue was corrected before the problem surfaced.
Contents inside rotating process equipment can be
especially difficult to measure with wired instruments. At
an Australian chemical company, leaking slip-ring seals
allowed the entry of moisture into the wired instruments
on a rotating reactor, resulting in unreliable readings.
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May 2009 CEP
After wireless pressure and temperature transmitters were
mounted on one end of the moving vessel, measurement
reliability increased and the once-frequent reactor breakdowns and associated lost production time became things
of the past.
Electrical heat tracing on pipelines and process vessels maintains the correct internal temperature, but wired
monitors to assure heater integrity are expensive to install
and maintain on lengthy pipelines. At a facility in Australia, bitumen unloaded from ships passes through a pipeline
that is heated to keep the bitumen hot (160ºC) and fluid. If
a heater segment fails, a cold spot could form, causing the
bitumen to solidify and plug the line, an expensive problem
to correct that is made worse if a delay in unloading keeps
a ship at the pier longer than planned, with demurrage
costing up to $30,000 per day. The terminal installed eight
wireless temperature transmitters along the 3,000-ft-long
(900 m), 8-in.-dia. (200 mm) pipeline, sending temperature
readings at one-minute intervals to an onshore gateway
that channels data to asset maintenance software for
instrument configuration and performance monitoring. The
data collected are also forwarded via fiber-optic cable to a
supervisory control and data acquisition (SCADA) system
in the terminal control center, so operators are informed of
the status of the heat tracing system.
Temporary measurements are easily handled by wireless, because systems integrators and end users can install
temporary transmitters in various parts of the process to
check on specific points during process startups or turnarounds and for troubleshooting.
An incineration manager in Singapore explains that it
is fairly simple to move a pressure transmitter from one
location to another to troubleshoot a problem. “I can often
determine what’s going on in just five minutes, address
the issue, and quickly return the transmitter to its original
application. The flexibility of the self-organizing wireless
technology makes it much easier to troubleshoot problems
as well as evaluate new applications.”
Implementing wireless field communications
The all-digital WirelessHART communications protocol is capable of working with any industrial instrument
application, whether for control or monitoring, just as all
HART products do currently.
Its mesh-based network offers many different paths
that transmissions can follow to reach the network gateway. The self-organizing network responds to changes
that affect the way radio signals propagate, whether those
changes are physical, such as equipment starting or stopping, trucks passing by, or other radio traffic, or due to an
outside influence such as a thunderstorm.
Transmissions can follow any one of several different
paths to the gateway and are not limited to line-of-sight
routings. Thus, there is no need for preliminary RF site surveys or assumptions as to what the RF characteristics will
be at any particular time.
The WirelessHART standard is based on the assumption that changes will occur fast and often. The environment will be very dynamic, and technicians will not have
the time or ability to react accordingly. Therefore, the
wireless network must react and reorganize automatically.
This is consistent with the legacy of HART in terms of
how data are acquired and utilized, and all modern control
systems today support that methodology. It will be very
easy for any existing control system that is compatible with
HART devices to integrate WirelessHART.
Consider a Wireless Field Network
when Your Application has …
•
•
•
•
•
•
Rules for network design
Begin with the supposition that all wireless networks
are easier and less costly to install than traditional wired
systems. Although self-organizing mesh networks do not
require site surveys, a certain amount of planning will
make the network operate more efficiently and reliably.
Some rules of thumb for designing a WirelessHART
network follow.
Plan to apply a field network project to a process unit
or area and obtain a scale drawing. Asset drawings are
good starting points. On a scale layout of the process unit
or area, identify the locations of desired field devices
according to the following criteria:
• The maximum effective range for wireless devices
with no obstructions is 750 ft (230 m).
• The maximum effective range for wireless devices
within moderate infrastructure is 250 ft (75 m).
• The maximum effective range for wireless devices
within heavy infrastructure is 100 ft (30 m).
• For the best functionality of the mesh network, each
wireless device should be connected to three other such
devices in the design of the network. The wireless connection distances between the devices may vary depending
on conditions, but should be within the previously stated
maximums. This assures a minimum of two pathways
when installed. If a wireless device does not have three
connections within maximum distance during the design
phase, additional measurement points or repeater devices
can be installed to fortify connectivity.
• Line-of-sight connections are not required in most
instances, but if a large building obstructs a wireless pathway or isolates a cluster of wireless devices, it may be best
to install another gateway to handle the traffic on each side
of the building.
• Devices installed in enclosed areas, such as an equipment room, may need to have an external antenna. Or a
repeater may need to be installed just outside the enclosure.
•
•
•
•
•
manually collected data — wireless can eliminate the
need to send technicians into the field to read gages
“must-have” measurements to satisfy environmental
or safety regulations — wireless allows the placement of instruments where needed
the need for diagnostics from HART-based
instruments
electrical classification problems — wireless
instruments can be installed in hazardous environments more easily than wired instruments
“want-to-have” measurements from locations that
could not be justified previously
long distances involved — wireless can eliminate the
need for long cable runs and trenching to
connect tank farms and similar assets spread over
a wide area
remote pumps and motors — wireless provides an
easy way to monitor many pumps and motors where
installing sensors would be prohibitively expensive
extreme environments — hot, dangerous, and/or
hazardous environments make it difficult to install
instruments and run wire; wireless minimizes the
problem
crowded environments — wireless eliminates
the need to snake new wires through crowded
enclosures and conduit
the need for feedback from manual valves that have
no connection to the DCS — wireless monitoring can
cost as little as 10% of a wired solution
mobile assets, remote sites, and rotating equipment
where using wired instruments is impossible, impractical, or too expensive
Integrating a wireless network
Integration of wireless field networks with plant networks will make business and process applications easier
to use and more robust, giving workers more power and
increasing their oversight of operations and the environment.
Valuable information will stream from field networks based
on the open interoperable WirelessHART standard and from
plant networks using industrial Wi-Fi standards.
Enterprise software architecture will improve, too, as
new web-based service-oriented architecture (SOA) makes
enterprise-to-factory-floor communication easier than ever.
For example, performance monitoring in plant field networks feeds plant and corporate optimization software, or
level monitoring in tank farms feeds inventory applications
to enable communications with customers, or diagnostics
from critical field devices are delivered directly to computerized maintenance management systems.
As with the transition between any two disparate
networks, the integration of wireless into a host control or
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Instrumentation
Modbus
OPC
Native
Interface
W Figure 6. Existing process
units can be made wireless
using various protocols for host
communications and adaptors
to transform wired devices into
wireless devices.
sensed” and “auto-configured” for quick and easy
startup and commissioning. In addition, HART
Smart Wireless
alerts from WirelessHART
Gateway
Coriolis Flowmeter
devices pass directly
with THUM
Wired Temperature
through to predictive
Transmitter
maintenance software,
with THUM
eliminating the need for
an additional network.
Wired Magnetic
Serial limitations. For
Flowmeter
with THUM
applications using a serial
Modbus communication
link, like that depicted in
Figure 6, the host system
Pressure
must have enough connecTransmitter
tion capacity available. To
Wireless
enable remote monitoring
Discrete
of the process variable and
Vibration
Transmitter
Transmitter
device status indicators,
Wired Digital
multiple Modbus registers
Valve Controller
High-Density
pH Transmitter
and Valve
Measurement
are needed for each data
with THUM
Transmitter
point. With serial systems,
Temperature
Transmitter
security measures are
limited to physical isolation
of
the
components
—
due
to
protocol limitations in the
information system relies on a gateway to translate signals,
existing
DCS/host
systems,
data
cannot
be encrypted and
for example, WirelessHART into Ethernet.
access
cannot
be
managed.
When adding a wireless network to an existing process
Ethernet options. If the host application requires inteunit, the interface requirements of the host system typically
gration
via Modbus TCP, OPC, or HTML, then either a
dictate the type of gateway interface that will be needed.
wireless
or wired Ethernet connection is needed. Ethernet
A wireless gateway can be integrated with a wide range
communications
have fewer restrictions than serial systems,
of host systems, as well as a wide range of programmable
but
may
require
the
involvement of the plant’s IT personnel,
logic controllers (PLCs), process historians, and other
who
can
identify
the
connection point, navigate the gateway
installed control systems (Figure 6) and protocols
through
Ethernet
fi
rewalls,
and provide remote access to the
(Table 1). A wireless adaptor can also be added to field
gateway.
Ethernet
also
allows
the gateway to be securely
devices in the existing process unit, enabling collection
managed
like
any
other
device
in an IT network.
and use of diagnostics or measurements not previously
Wireless
Ethernet
provides
enough
bandwidth to comaccessible in a central host.
municate
both
diagnostic
and
measurement
data. In fact, with
Go native. The best-case scenario for wireless intepower
as
its
only
need,
the
gateway
can
be
placed
almost
gration is a host system that includes native support for
anywhere
within
range
of
the
devices
and
the
host
connection.
wireless devices, as depicted in Figure 1. Indeed, for users
The
gateway
can
generally
be
moved,
if
necessary.
of these systems, wired and wireless field devices appear
transparently on the host system with no special software
Getting started
or communication know-how.
In the latest versions of systems with a native interface,
A wireless infrastructure can be installed very easily
more-advanced wireless gateways can even be “autofor use with a plant’s existing devices and control system.
Modbus
Serial
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May 2009 CEP
Table 1. Primary wireless integration protocols
Protocol
Typical Host
Modbus / Remote Terminal Unit (RTU)
Distributed control systems (DCSs)
and programmable logic controllers (PLCs)
Modbus / Transmission Control Protocol (TCP)
DCSs, PLCs, and human-machine interfaces (HMIs)
OLE for Process Control (OPC)
Data historians and HMIs
Ethernet
Asset management systems and other applications on the plant local
area network (LAN)
Hypertext Transfer Protocol (HTTP)
Web interfaces used for configuration and simple monitoring
Extensible Markup Language (XML)
and Comma Separated Values (CSV)
Bulk data transfer
Many plants start small with a wireless field network of a
few devices communicating with a single gateway. The first
wireless point is inevitably the most expensive — to deploy
one transmitter, it is also necessary to install the gateway,
computer, software, etc. However, once this infrastructure
is in place, installing each subsequent transmitter will cost
very little more than the device itself, since one gateway
typically supports up to 100 transmitters. Many gateways
can be added to the network, each with up to 100 devices
— allowing for massive scalability.
Monitoring applications offer a good opportunity to
evaluate the technology with little or no risk. You can
obtain a relatively inexpensive wireless starter kit without a capital expenditure. Then, involve all departments
— engineering, operations, maintenance, etc. — to allow
everyone to see how wireless technology can enhance
equipment reliability, reduce plant downtime, improve
process control, and create a safer workplace.
Once the first wireless network begins to function, the
operations and maintenance staffs will find other applications around the plant for additional process data collection
and asset monitoring.
As noted earlier, the wired and wireless worlds are
easily integrated in a single, scalable infrastructure. As
a result, the benefits of the digital plant architecture are
extended to assets that were previously out of physical
and economic reach. Since this approach is based wholly
on open standards, system designers can choose from a
variety of wireless solutions without being tied to a specific
technology or vendor.
Looking ahead
The evolution from a wired world to a wired-and-wireless
world will continue as management recognizes the enormous
potential for continuous improvement. Corporate technology
groups, as well as IT and process automation personnel, are
collaborating in cross-functional teams to investigate and
implement new technology for operations, always working to
improve safety, the environment, and production. In addition
to existing-facility upgrades, there is potential for wireless to
replace wired instrumentation in new plants.
The door to the world of wireless is open for suppliers
to develop new wireless products and users to develop
applications that add value to an industrial process
without concern about the underlying technology. This
is somewhat like the emergence of the Internet, which
turned loose a proliferation of innovative applications
not even imagined before. We are on the cusp of a similar
revolution in this new age of wireless for industrial
process automation.
On the strength of the high reliability and performance
qualities of self-organizing WirelessHART mesh networks,
and the clear economic advantages they offer, we believe
WirelessHART technology will account for 20% of the
CEP
signals in new plants within five years.
PETER ZORNIO, chief strategic officer for Emerson Process Management,
directs strategic initiatives for Emerson, including the expansion
of PlantWeb digital plant architecture to include process and plant
networks that deliver a complete solution for improved productivity,
safety, and operational efficiency of process manufacturing facilities.
Zornio has a leadership role in prioritizing technology investments
and identifying acquisition candidates. He has strong background
with fieldbus technologies, which combine with emerging wireless technologies as the communications foundation of PlantWeb
and other leading Emerson Process Management technologies. A
24-year veteran of the process automation industry, he was most
recently director of product marketing for Honeywell, where he was
responsible for control systems, safety systems, and software for
asset management and manufacturing execution. He also worked
with measurement products, and the acquisition and integration of a
major automation company. He has a BS in chemical engineering from
the Univ. of New Hampshire.
BOB KARSCHNIA, vice president of wireless for the Rosemount Measurement Div., has over 16 years of experience in the process control
industry. He currently manages the Wireless Business Unit for
Rosemount’s wireless product offerings and coordinates wireless
initiatives across all of Emerson Process Management. Previously, he
held various design engineering and management roles throughout
the company. Before joining Rosemount, he developed rotatingequipment control systems at Compressor Controls Corp. and satellite
control systems for Lockheed Martin. He also served as an officer in
the U.S. Air Force working on satellite control and communications
systems. He has a BS in aerospace engineering from the Univ. of Minnesota and an MS in electrical engineering from the Univ. of Colorado.
CEP May 2009
www.aiche.org/cep
29
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