With dazzling wireless technology now available, it’s tempting for manufacturers to snatch up any wireless sensor that comes along as a means of optimizing processes and plant performance. This is especially true within the pharmaceutical industry, where vendors are plying industrial-strength wireless sensors for temperature, humidity and pressure, as well as sensitive process-monitoring wireless devices to support PAT applications.
But drug and other manufacturers may do well to exercise more caution when it comes to wireless. At least that’s the resounding message sent by a panel of experts who spoke on the current state of wireless standards at October’s annual ISA (International Society of Automation) Expo meeting in Houston.
The discussion drew an overflow crowd, and it was clear why the audience members, mostly from the end user community, had come: “Help!” If anything, wireless standards for industrial purposes have been getting more complex and confusing of late (see Box), and the audience was looking for a little comforting advice.
It did not come right away. “The wireless landscape is pretty confused, and will probably stay that way for a long, long time,” said wireless guru Hesh Kagan, Director of New Business Opportunities for Invensys Process Systems, near the start of the session. “Interoperability and coexistence are the issues we’re really grappling with, and I don’t have a prediction where standards will go, other than clearly they want to follow mass-market technology, which is driven by the communications and cell phone world.”
Jose Gutierrez, Corporate Director of Technology for Emerson Electric, agreed that telecommuncations companies are leading the advance of wireless technology, and cited what is being called Fourth Generation Broadband as a mobile, wireless technology that will have a transformative impact upon the wireless world in time. The problem is, as the panel pointed out, what’s good for commercial applications is rarely right for industrial ones. What’s a plant engineer with responsibility for wireless applications and planning to do?
Fortunately, the panel did get around to offering guidance and constructive advice, summarized here:
- Have a corporate wireless strategy. This strategy should be top-down and consider how wireless can work within the wired facility and within the company’s business model.
- Have a committee. Wireless decisions in one part of the plant can have far-reaching implications, and may even be antithetical to efforts elsewhere or to the business mission.
- Collaborate. In particular, get control and IT working together in decision-making.
- Start small. Try some wireless alerting and monitoring on a part of your plant that is not critical.
- Proceed cautiously.
Hail to the Incumbent
One of the problems with the wireless world of today is that, as in politics, the incumbent has the edge. Harry Forbes, an analyst with ARC advisory group, noted how the most accepted wireless (and wired, for that matter) protocols were also the oldest. People will stick to the same technology for a given application unless there’s a good reason for them to shift to a new one, Forbes noted. Thus for wireless, a Babel of standards has evolved.
Incumbency isn’t necessarily a bad thing, noted Ed Ladd, technical director for the HART Communication Foundation. “The old standards have migrated forward as the technology has improved,” he says. “These are evolutionary standards.”
There has been sufficient evolution to give most plant engineers the tools they need to build an effective wireless system, noted session moderator and Control magazine editor in chief Walt Boyes—this includes both industrial- and process-monitoring applications. “The landscape today is completely confused, as Hesh said,” said Boyes. “There’s all of these technologies, many of which are academic and not intended for industrial applications.”
However, Boyes noted, “there are three sensor network standards that you’re going to be seeing products from soon, in the next six months.” These include ZigBee, Wireless HART, and ISA100—though the ISA standards are not yet ratified, vendors are already developing prototypes for market based on ISA100.
“For purposes of what you’ve got to do as a decision maker, the standards are here,” Boyes said. “What isn’t here is the engineering tools to help you make those decisions. Companies need to develop those tools, and those are unfortunately behind the development of the standards.”
As others in the panel would do, Boyes cautioned engineers to develop their wireless strategies carefully and slowly. “Pay very careful attention and do it properly, or you will do rip and replace,” he said.
“Think about what you can deploy, how you can deploy, and how you can sustain it in the long run,” said Pat Schweitzer, Instrument Team Lead at ExxonMobil. “Because you basically can’t take it out of service.”
As Kagan put it, “The standard is secondary to the solution,” said Kagan.
What’s Your Strategy?
Honeywell’s David Kaufman, Business Development Director for Wireless Technologies, agreed that companies must be very shrewd in planning for wireless.“There are limitations in using wireless,” he said. “It’s not going to do everything you want to do, and you only have so much bandwidth. It time you will use all that up unless new bands open up.”
“I have talked to customers that have actually used up their bandwidth,” Kaufman said. These customers began to install wireless implementations and incrementally used up their entire band. “Were those the most important things that you wanted to use wireless for in your plant?” Kaufman asked the customer. “No,” the reply came. “They just kind of snuck in.”