New ideas in Industrial Automation

Aug. 23, 2007
Network protocol advances manufacturing and IT.

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.

A FlexCell cartoner with a DeviceNet network works in tandem with EtherNet/IP, letting a manufacturer control all its cartoners from one operator interface. Additional ports on the local Ethernet switch plug into a plant-wide network.

A packing machine networked with the enterprise can send maintenance personal e-mail alerts should the machine need work.

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