Connecting and maintaining thousands of points in complex industrial applications that demand extremely high reliability hasn’t become a simple task despite the best efforts of the brightest minds in the industry.
As Ethernet takes over in the factory, one of the obstacles is that the information technology (IT) people who have set up corporate networking schemes don’t fully understand the requirements of manufacturing environments. When these IT specialists set up industrial networks, they are often surprised to find that the front-office design techniques they’ve used successfully for years don’t work.
“Everyone needs to quantify expectations. IT people often feel 90 percent uptime works, while manufacturing is looking for 99.9 percent. There’s no reason IT people can’t support high reliability. They just need to understand what it means in manufacturing,” says Brian Oulton, networks marketing director at vendor Rockwell Automation Inc., Milwaukee.
That underscores a fundamental challenge for many technical fields. The tools and technology are often well understood, but only by a very limited number of experts. If a design team doesn’t have someone who’s knowledgeable enough to troubleshoot all the issues, the job isn’t simple.
Real learning
That’s particularly true when IT and manufacturing people work in areas where the disparate nature of the two environments brings issues that touch on both sides of the divide. “When all is said and done, often it’s not a technical question. It’s more an education process recognizing the different needs for manufacturing and IT,” says Claus Abildgren, marketing program manager at Wonderware. “If the IT administrator spends a few days working side-by-side with process engineers, this is when real learning occurs.”
That said, tool makers continue to make their software more user-friendly. Rockwell Automation and San Jose, Calif.-based network products vendor Cisco Systems Inc. have addressed this by designing tools that leverage their experience in each area.
“Jointly developed products support CIP (Common Industrial Protocol) and traditional SNMP (Simple Network Management Protocol). That way, people can use tools they’re familiar with,” Oulton says.
Sidebar - New Approaches Help Broaden Ethernet's Reach
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But no matter how much product designers focus on simplicity, the tools can’t address everything. “When you start getting into the details, there are still issues, like what tools people will use and who owns what. There are still historical differences where the two organizations use the same words but with different meanings,” says Dan Knight, industry solutions manager at Cisco.
Those semantical issues even flow into systems that communicate between machines, leaving humans out of the loop. Just as with humans, terms or commands must be clearly understood by all parties to avoid problems.
“Machine-to-machine communications can be accomplished today. But if one machine doesn’t know what an alarm means to another machine, it doesn’t do much good,” Abildgren says.
He notes that the Organization for Manufacturing Automation and Control (OMAC, previously the Open Modular Architecture Control Users Group) has addressed this issue. OMAC put together proposals within the structures of the PackML state model that prescribe the states that machines can be in. “If you buy packaging machines from 10 vendors and they all use PackML, in theory, you could plug them in and start working,” Abildgren says.
Losing battle
The efforts of standards bodies and companies that constantly address user friendliness, compatibility and ease-of-use have brought a number of successes that make life easier for users. But most participants in these development activities acknowledge that they’re fighting something of a losing battle.
The non-stop advances of the electronics and communications industries helps alleviate complexity, but it also creates new headaches for integrators. When issues with one version of a standard become well known, an improved version emerges, bringing new questions that need to be ironed out.
New technologies also enter the fray. Wireless networks weren’t considered to be reliable enough in harsh industrial environments, but reliability concerns have been reduced dramatically. As a result, wireless applications are seeing increasing acceptance in many areas, forcing plant floor engineers and IT staffers to learn the ins and outs of deploying wireless in noisy industrial environments.
“As we go forward, wireless is going to play a greater role. Wi-Fi, Hart protocols and vendor-specific networks are really moving forward,” Abildgren says. Eventually, he predicts, broadband standard WiMAX will play a significant role in factories. Its long range—up to four or five miles—makes it attractive to large plants or companies with campus-like settings.
