Overcoming real and imagined barriers to wireless adoption
Wireless is being used now more than ever in control architectures. It is flexible, versatile and can be cost
effective. However, concerns with the security, reliability, and capacity of wireless continue to prevent
conservative end users from reaping its benefits. Are these concerns valid? Adrienne Lutovsky disentangles
the misconceptions from genuine challenges, providing insight about how to overcome obstacles now and
down the road with proper understanding, planning and execution.
IS WIRELESS BETTER or worse than a wired
network? The answer is no; it's different. A
plethora of wireless technologies exists to suit
a variety of users. Is it for every application?
No¡ But for many, wireless can be more
flexible, versatile and cost effective than wired
networks. Yet, questions regarding security,
reliability and capacity of wireless continue to
prevent conservative end users from reaping
its benefits. Can these be overcome?
Security is the first topic to arise when
discussing wireless in a plant network and the
decision to deploy is often not one made in
isolation. Plant engineers want to ensure uninterrupted
production, and that security measures
are in place to protect their process and plant
floor equipment. IT engineers want to ensure
that systems deployed in the plant co-exist well
with networks in the rest of the organisation
and that nothing compromises the security of
corporate information. Though different, the
concerns of both the plant-floor engineer and
the IT engineer are of high importance.
Today, the mechanisms are in place for
industrial wireless systems to address the issues
of both stakeholders. However, understanding
what capabilities exist in wireless networking
devices and how to use them for the
betterment of the operation is not always
appreciated. Modern encryption techniques can
be used to avoid someone interpreting your
data maliciously. Filtering and strong authentication
allow only authorised devices on the
network. The mechanisms that are relied upon
by the US government for transferring secret
information are present in today's industrial
wireless devices, and address many of the
concerns of security of information, assets and
reliability of processes.
So, do not view the discussion on security
for a plant network as one in which IT
engineers and plant engineers have competing
interests. Instead, acknowledge that each has
their own experiences. Plant engineers have
depth of experience in around-the-clock reliability
and the role reliability plays when
deploying automation networks. IT engineers
have depth of experience in co-existence of
multiple systems and network management.
The two can complement each other if cooperation
Wireless isn't a drag: The autobody plant in the
Gestamp plant at McCalla,Alabama uses a 1000-tonne
sheet metal press.Wireless Ethernet is permanently
attached to the massive, floor-movable die carriers
replacing problematic drag cables.
Getting IT onboard
Swallow the lump in your throat and engage IT
from the get-go. The IT people have most likely
deployed wireless more pervasively throughout
their networks and will want to incorporate their
best practices, allocate frequencies to ensure
coexistence with other networks, and potentially
help plan which technologies will be used.
If IT is not included in the process and you
proceed with your system, they can and will
shut you down.
Lean on your solution provider. They should
understand the needs of both departments and
can bridge this gap to find a common solution.
Open the dialogue about the security measures
that can be put in place to achieve the same
level of security as they are accustomed to with
the wired systems. Today, with the standards
that are in place, a fully provisioned wireless
system can lock down the network securely and
satisfy enterprise requirements. Sometimes this
involves getting around red tape.
For example, heavily regulated industries like
pharmaceutical must adhere to strict data
collection specifications, so the IT departments
are more sensitive to security concerns. It is
important to be clear on what you need and
what IT will need from you in order for them to
feel comfortable with your technology decision.
I'm a control person and now I've brought IT
in on my system. Pose the questions: 'So, who
owns my network in the event of a system
down?' 'How quickly can it be handled?' 'How
quickly can it be diagnosed?'
This is where it gets tricky. We are control
people. Relinquishing decisions about our
processes is antipodal to our natures. Who
controls the network often comes down to the
policy that exists or is set in place. With wireless,
the same rules of demarcation should apply as
would with Ethernet. In some cases, IT owns
anything connected to Ethernet. In other cases,
the plant floor will own anything producing
output. Sometimes IT will be involved in the
decision making process and frequency
allocation, but the plant has responsibility for
installation and maintenance of the system. In
any case, what becomes important is that the
line of demarcation be established upfront and
that the selected wireless technology provides
the diagnostic tools to satisfy both of these
The tools for IT and the plant floor may differ.
Having the appropriate tools for each is critical
to prompt resolution. In the IT world, tools are
based on SNMP, which is supported by some
industrial radios. Higher level diagnostics may
include OPC level data that can be used to
integrate diagnostics into the control system.
Though policy varies from one organisation to
another, the trend seems to follow suit of wired
Ethernet on the plant floor. Whether wired or
wireless, when a line goes down at two in the
morning, it is the plant manager whose phone
rings. Regardless of who owns the network, it
is fair to say that troubleshooting a wireless
network has a different process than with a
wired Ethernet system. A wireless network is not
tangible, for one. You cannot hold it in your
hand. It can be affected by outside contamination,
which can widen the scope when trying to
isolate the root cause of a problem. This is why
it is essential to have proper tools in place to
monitor and diagnose your system.
As with every other essential component in
your system, have someone clearly identified
who knows how to use these tools and understands
the equipment. Select a vendor that can
support you throughout your implementation
and down the road, with the proper tools and
training, technology selection, and technical
support program. With these things in place,
someone who is familiar with doing the diagnostics
on a wired network can also diagnose
the wireless network.
How can I feel assured that a wireless system
will meet my bandwidth requirements, especially
down the road?
Firstly, do your homework. Know your network
demands, your goals, and the environment you are
dealing with. What are the distances and speeds
you require? Do you need mobile worker access?
Is your application indoor or outdoor? Are there
reflective surfaces? Will there be moving, rotating
and vibrating machinery? Will you be able to
articulate what traffic your network is expected
to support. There are many flavours of wireless,
each suited for different applications.
Secondly, choose your service provider
carefully. Work with industrial grade technology
from a vendor that can confidently determine
what you need in your specific application -
and can select a scalable solution to accommodate
your growth. Select vendors with a strong
understanding of your equipment and your
process. Look for the right combination of
diagnostic tools. Some vendors provide HMI integration
tools using OPC to give you a visual
overlay of your network. Verify whether the
company offers value-added services, such as
path studies and site audits. These are things
to look for when specifying projects.
Some applications, however, simply cannot be
supported by wireless. For example, production
lines using 1000 I/O points with millisecond
scan rates. Wireless technologies today cannot
deal with this level of capacity.
How can I protect my network from interference
if a neighbouring facility installs its own wireless
Be conscious of what else is in place. Think of
IT as an asset. Use the IT peoples' domain
expertise and build a maintenance program for
monitoring the health of the system. A solid
understanding of the necessary criteria can
provide the ability to anticipate wireless performance
over time. IT can sniff the network
periodically, monitor for new participants or
other change in the wireless environment -
measure outside interference and ensure performance
is not diminished.
However, even a perfectly implemented
network with a well-laid plan for isolating interference
is vulnerable to the ever-changing RF
environment. You cannot know if a neighbour
will move in and interfere with your network,
but you can take precautions or adjust you applications
later to limit impact.
Several precautionary options exist. To start
with, it is wise to choose a solution with flexible
frequencies that can be changed if needed
(802.11n has 24 channels in the 5GHz band).
Another effective method is the use of directional
antennas to strengthen the connection
between radios and to reduce sensitivity to
interference. Lining up directional antennas,
however ¡ª particularly at farther distances ¡ª
can be difficult. Advanced installation
techniques such as these are often set in place
during site surveys, performed by top tier
Is wireless any less reliable than a wired system?
The answer is no, it's different. In the same way
that a user would not run cable next to drives
because of interference, wireless interference must
be considered. Wireless simply requires different
steps. Factors such as line of sight and selection
of radio, antenna and cable become important.
Consider the specific performance features of
these devices against your application.
In many cases, a wired system can be less
reliable, particularly with moving equipment
where slip-rings are used for communication.
The nature of these applications subjects cable
to continuous flexing, breakage or degradation
Wireless in control
Wireless has long been successful in SCADA, but
in control too? In many cases, yes. In manufacturing,
Ethernet is now widely used in control;
and where there is Ethernet, wireless often
follows. Some wireless devices are sophisticated
enough to act as managed switches, providing
intelligent packet filtering. Some support deterministic
applications, and can provide a high
level of flexibility, speed, precision and
predictability. In these projects it is critical that
the design and technology of the system be
carefully planned and executed, working closely
with distributor specialists, integrators and
Engage IT from the start: The IT people are likely to have
deployed wireless throughout their networks and will
want to incorporate their best practices. IT engineers want
to ensure that systems deployed in the plant co-exist well
with networks in the rest of the organisation and that
nothing compromises the security of corporate
information. Though different, the concerns of both plantfloor
engineer and the IT engineer are highly important.
Another battle is the classic, 'perception is reliability'
clich¨¦. Any person with a computer and
Internet service has experience with wireless,
generally riddled with memories of crashing
routers and resetting modems. Who wants to risk
this in their plant? Today, wireless products exist
that are far more robust and reliable for industrial
environments than traditional consumer or even
enterprise level technologies. There are new
techniques and testing tools available to
determine when the network is approaching
failure, and user interfaces to provide real-time
health information. There are repeatable
technology management and procedural
management systems that can be put in place
to increase reliability.
Many real-world wireless applications have
actually improved efficiency and reliability by
trading their wires for antennas. Applications with
moving equipment can dramatically reduce costs,
downtime, and maintenance using wireless.
For example, Proctor & Gamble migrated to
wireless specifically to improve reliability. In
the plant, the company replaced slip rings with
a wireless network that was designed to optimise
its existing EtherNet/IP network. Proctor &
Gamble used an 802.11 solution on a 5GHz
frequency in order to co-exist with an already
saturated 2.4GHz band. The company was able
to meet performance requirements with determinism,
experienced fewer dropped packets, had
no downtime from communication errors, and
ultimately received a strong buy-in from plant
In a second example, Liberty Airport Systems
of Ontario, Canada, designs custom runway
lighting systems for commercial and government
airfields. The reliability of these lighting systems
is critical to facilitate aircraft movement, so
downtime can translate into flights being
delayed, cancelled, rerouted, or in worst case
scenarios, an incursion.
The primary fibre optic communication lines
run underneath airfield runways, and in the
event that they are damaged, can shut down
the entire runway. Liberty now uses wireless as
the independent backup communication system
for many of its installations in order to increase
uptime and cut maintenance costs. In one installation,
the fibre line was severed during
construction, and the wireless backup system
seamlessly carried on communication for a week
while the fibre line was repaired.
The keys to overcoming obstacles now and down
the road begin with proper understanding,
planning and execution of your wireless network.
Wireless is not a 'set it, forget it' solution. Audit
your network. Engage with IT people early on.
Give them what they need to feel comfortable
with the plan, and they will often help take care
of the network. With these things in place, users
can enjoy the flexibility and versatility innate
to wireless, and in many cases, reduce costs.
Adrienne Lutovsky works for ProSoft Technology