Brian Oulton
Networks Manager
Rockwell Automation
Mayfield Heights, Ohio
Forward-looking machine
builders understand that
the increasing use of EtherNet/IP technology will
significantly affect how
the plant floor and IT work
together at customer
sites. For starters, the
protocol helps companies
automate by fostering
communication among
individuals, devices, and
equipment across the factory floor and throughout
the company.
The EtherNet/IP protocol uses standard, unmodified Ethernet and the same Common Industrial
Protocol (CIP) used in DeviceNet.
CIP delivers real-time I/O and
drive control, information for human-machine interfaces, and controller-to-controller communication. Standard Ethernet is used
in such familiar office tasks as delivering e-mail, Web pages, voice,
and video, and in most corporatecomputing functions. With over
1.3 million nodes installed worldwide, and three of the top five
global automation suppliers supporting EtherNet/IP in core control architectures, the technology makes networking in manufacturing work just like any other node
on the enterprise network.
Merging plant-floor and IT networks using EtherNet/IP means
different things to different customers. Some are running multiple functions on the same wire to
cut costs and training time. Others have a different goal in mind,
for instance, developing a shared
expertise, common language, and
a list of best practices.
Rockwell Automation and
Cisco Systems in San Jose, are
working together and with standards organizations to help develop reference architectures. They are a series of thoroughly
tested guidelines and design recommendations for using EtherNet/IP in real-time manufacturing. A few of the many guideline
topics include security, reliability,
wired versus wireless, and choice
of topologies.
OEMs that include EtherNet/IP
capabilities in machines are ahead
of the game because the technology allows predictive maintenance and quick handling of
customer machine problems. For
example, EtherNet/IP networks boost troubleshooting efficiency. Technicians can directly connect to
a machine from remote locations and determine its
status in a variety of ways. Cameras can be mounted
in areas that are
inaccessible to operators, providing
machine images
to individuals inside and outside
the plant. Web interfaces can supply technicians
critical machine
data and, with appropriate safety
measures in place,
technicians can
even make program changes remotely. This helps
reduce customer
downtime and
cut OEM time and
travel costs.
In addition, EtherNet/IP networks let OEMs remotely administer firmware and software upgrades. Machine updates can be sent directly
to the machine, or to workers via e-mails and text
messages to mobile phones. These same capabilities can be used to order replacement parts or raw
materials. For example, when a machine breaks
down, the control system sends an e-mail to a local
distributor to replenish the failed part.
When is Ethernet
not Ethernet?
Nearly a dozen industrial Ethernet networks have appeared
in the past 10 years. However, they vary considerably,
with several so far removed
from the standard that they
shouldn't even carry the same
name.
For example, some protocols described as "standardsbased" start out using a network standard. But ultimately
they deviate to a proprietary
network that can be hard to
learn and difficult to integrate
with previously installed Ethernet versions. The protocols
usually violate the hardwarelayer standards (IEEE-802.3)
or ones for the middle layer,
called TCP/IP/UDP — the language used by the Internet and
e-mail. Lack of TCP/IP/UDP
can make for a network that
plugs together, but doesn't
play together. Such networks
might use standard Ethernet
cable, but require proprietary
switches. Also, they may be
incompatible with standard
IT network management or
troubleshooting tools. Special
training and services are often
needed to make the networks
work. Fortunately, EtherNet/
IP doesn't have these issues,
as it is a standard, unmodified
Ethernet protocol. |