Techniques for Better Network Management

What is plant-floor network management’s most important issue? It’s uptime or availability, says Mark Wylie, manufacturing solutions manager for Cisco Systems (www.cisco.com), San Jose, Calif. He lists security as number two. “I now have this giant network that I’ve linked together. I need to make sure all of the devices are on or should be on that network—and I need to be able to recognize and configure those,” Wylie explains. More secure networks are possible through a common networking infrastructure, which is open-standard, unmodified Ethernet, he adds.

Indeed, a common Ethernet-based network is often the best solution, says Mike Miclot, director of commercial programs, integrated architecture, for Rockwell Automation Inc. (www.rockwellautomation.com), in Mayfield Heights, Ohio. He notes that such networks may have very high bandwidth, which is overkill for most automation applications. Nevertheless, Miclot adds, because Ethernet is native to both manufacturing-execution and enterprise-planning systems, it provides easier connectivity from the plant floor to the rest of the enterprise.

But caveat emptor, Miclot advises. “Do your homework. Not all Ethernet application layers (from different vendors) are the same. And you want to make sure that the Ethernet solution you choose does sequential motion and safety control,” he states.

With a common network, end-users have a backbone that can help ease the burden of network management, which Miclot says is composed of maintenance and forecasting. Forecasting relates to predicting how much traffic will be on the network, he explains, adding that server space and memory are both associated with traffic issues.

Traffic management relates directly to the availability issue that Wylie raises. But how do end-users manage this traffic? One method he suggests is use of a notification system for monitoring and diagnostics, as well as a backup plan.

Traffic management Charlottesville, Va.-based Frontline Test Equipment Inc.(www.fte.com)、发展协议分析仪的技术gy that could assist. “It analyzes traffic. It sits on top of the network and sniffs what’s going on,” explains Bill Drake, Frontline’s director of operations. “It allows the end-user to optimize the network’s performance and to detect deterioration before it creates a critical situation,” he explains. And that is the true importance of proper, timely network management.

Besides traffic issues, more general network operations exist in which controls systems engineers and technicians still must locate problems before they can be fixed.

“Seeing is understanding. If you can see something, then you can ask questions,” says Mark Fondl, president of Network Vision Inc. (www.intravue.com), Newburyport, Mass. Conceptually, that’s important for most, if not all, problem solving, but it is vital for good network management. “Visualization tools for network management are like pulling the curtain back on the Wizard of Oz: You expose what is really going on,” Fondl asserts. And that gives control engineers the ability to identify and fix problems, which he suggests are in connected devices—not software—90 percent of the time.

There’s also another big issue in network management, Fondl believes. Though information technology (IT) groups typically “own” the networks, he observes, they really have the primary responsibility of ensuring data flow within a company. The controls systems groups should be responsible for the plant-floor network because, Fondl says, because the data are theirs.

C. Kenna Amos,ckamosjr@earthlink.net, is an Automation World Contributing Editor.