industrial wireless book special edition - Networking ...

RFID
Tracking assets: RFID meets
industrial Wi-Fi networks
Globalisation and mobility trends have profoundly affected industrial plant operations and entire business
models, with assets that make up the supply chain being constantly in motion. Efficiently managing people,
products, equipment and raw materials is essential to keep global manufacturers competitive. One fast
growing technique that enables this is a combination of wireless networks with RFID technology.
IN THE PAST, a lack of visibility into the
location of valuable assets has hindered
efficiency and resulted in operational problems
such as misplaced mobile tools, jigs, machinery,
parts, or work-in-process (WIP) inventory. This
results in high equipment leasing and/or
replacement costs to offset losses.
Worker safety and security is another issue.
Accidents and security incidents can make it
life-critical to quickly locate employees and
building exit routes. Context-aware conditions
help minimise injury and losses. As manufacturers
seek to continuously improve business
agility, quality, reliability and safety, they are
taking advantage of increasing intelligence in
devices and networks.
Increasingly ‘smart’ devices, which include radio
frequency identification (RFID) tags and sensors
that have advanced diagnostics, are contributing
to the billions of devices now connected to IP
networks. This proliferation of smart devices is
referred to by some as the ‘Internet of Things’, and
it is projected to grow to trillions of devices that
will be connected using the emerging IPv6
protocol 1 . For manufacturers, a growing number
of connected smart devices promises to revolutionise
portability, mobility, context-aware
condition and use of critical assets.
However, devices must be continuously
connected – including in tough manufacturing
environments – and be integrated to deliver
context-rich information, alongside with data.
The combination of smart devices with wireless
networks is now able to deliver powerful smart
services, such as context-aware, real-time asset
management and location services.
PHOTO: CISCO
Indeed, the past year has seen an explosion of
RFID solutions used to track almost everything
imaginable.
Research firm Gartner suggests that the
explosion of mobile smart devices is leading
to an equivalent explosion of mobile applications,
which will create new wireless
infrastructure requirements 3 . When RFID
solutions are teamed with wireless networks,
manufacturers can suddenly increase operational
visibility almost anywhere. Today, RFID
and wireless networks are able to deliver
immediate, unprecedented visibility into assets,
WIP and people’s locations.
Manufacturers have been piloting and
deploying RFID in their organisations for some
time, and several trends are developing.
Passive or active?
There are both ‘passive’ and ‘active’ RFID tag
types. Passive RFID uses low cost tags that are
generally disposable as consumables (as used
in shops to prevent theft etc), while active
RFID uses more sophisticated tags that cost a
little more at typically Euro 17 – 68 ($25-
$100). There is also a third type – semi-passive
tags. These are similar to active tags in that
they use a battery to run the microchip’s
circuitry, but they cannot communicate with
RFID readers. To conserve battery life, some
semi-passive tags remain in a ‘sleep’ mode until
contacted by a reader.
Active RFID tags possess greater functionality
and tend to be associated with supply
chain or manufacturing process workflows. They
are reusable and have batteries that last five
or more years. Active RFID tags can also
function as low-cost remote sensors that
broadcast telemetry back to a base station.
Active-RFID deployment is a sector that is
seeing good payback and return on investment
for manufacturers.
Looking at wireless transmission, work with
RFID and the Real Time Location System (RTLS)
has led to the development and support of
multiple RFID technologies. The first is
Received Signal Strength Indicator (RSSI). This
is a measurement of the power present in a
received radio signal. RSSI is generic radio
receiver technology metric, which is usually
invisible to the user of the device containing
the receiver, but is directly known to users of
wireless networking of the IEEE 802.11 protocol
family.
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RFID + wireless
Technology analyst firm IDC included smart
services using RFID as one of its ten
Manufacturing Industry Predictions for 2011 2 .
industrial ethernet book
sponsored by Advantech
PHOTO: CISCO