Wither Wireless OI?

The Technology for Handlheld Machine Monitoring Applications Has Been Around for Years, So Why Aren't You Using It?


Way back in 1991, Tom Mefford, an engineer at Positech in Laurens, Iowa, built a radio-controlled manipulator for Northrup to handle parts on the B2 bomber during assembly. Mefford says the manipulator rarely was used, then abandoned by Northrup.

That seems to sum up the history of wireless technology in the machine builder industry: The technology has been available for quite some time, people tried it, but nobody is using it.

The Technology Is Here

Wireless control technology has been around for a long time. Not only did Mefford use it in a manipulator 12 years ago, people were controlling overhead cranes with wireless devices way before that. Wireless warehousing operations have been up and running for 20 years.

Although machine builders are still shy, vendors and end users on the process industries side of automation have been using the technology for several years. In 2001, at least one process control system vendor was supplying wireless PDA-based human-machine interfaces (HMIs). "We have to provide wireless HMIs these days, especially for compressor controls," says Roman Rammler, president of Micon Systems LLC (www.miconsystems.com). "Engineers like to walk around a compressor train with an HMI in their hand."

At the time of that report, Micon's handheld HMI (Figure 1) had been available only for four months, but Rammler said it had been partially responsible for landing several major control system orders. Now, the handheld is an integral part of the Micon product offering.

Some people find wireless technology extremely attractive, especially when long distances are involved, since running hard wiring can be expensive. "We are a system integrator that works primarily with water and wastewater utilities," says Larry Weinheimer, control engineer at Byrd Industrial Electronics (www.byrdelectronics.com). "The Wi-Fi systems we have installed involve monitoring and control of water systems including level monitoring, pump control, and security monitoring. We have deployed handheld devices into these systems, using [IEEE] 802.11b methods to access data from almost anywhere in the system."

Building automation is going wireless, too, says ARC Advisory Group (www.arcweb.com), and for the same reason. "The leading impetus for considering wireless sensors and controls for building automation applications is fundamentally to lower the cost of wiring," says David Clayton, ARC analyst.

Manufacturing operations are taking to wireless. The Toyota plant in Princeton, Ind., uses wireless monitors to observe work in process, and the Johnson Controls plant in Ossian, Ind., uses wireless HMIs on forklifts to tell operators what to pick.

Two of the most advanced HMI/SCADA software companies in the business--Iconics (www.iconics.com) and InduSoft (www.indusoft.com)--have been hawking handheld HMIs for years. They've run countless demos at trade shows with their pocket PCs and Casio PDAs. Both have had some success selling into the process industries, but not to machine builders.

PDAs certainly are a reliable, proven technology. Upward of 30 million Palm PDAs have been sold to date, and it's likely a similar number of wireless pocket PCs, handhelds, and tablet PCs have been sold. Prices for PDAs range from $299, and HMI software is readily available at reasonable prices for machine builders and similar OEMs.

For those who prefer a more industrial HMI, Rockwell Automation (www.rockwellautomation.com) offers the MobileView portable tablet PC (Figure 2). Concept Systems (www.conceptsystems.com) is introducing its PlantLinq wireless troubleshooting, alarm reporting, and machine control system (Figure 3). It's based on a standard PDA, but has software suitable for monitoring machine operations.

So, it's apparent the technology is here. Why aren't machine builders using it?

Emergency Stops and Other Hang-Ups

Jim Taylor, group manager for industrial automation at industry analyst Venture Development (www.vdc-corp.com), conducted a study of industrial wireless use in North America last year and he agrees that machine builders have not been using wireless.

"Our study forecast good growth in wireless operator interface terminals for use with material handling equipment, particularly conveyors," says Taylor. "On site operator interface (OI) terminals will grow to be the largest market segment for OIs in 2006, but most of these applications will not be in real-time control. Rather, the largest application for these is expected to be in mobile programming, maintenance, and repair applications. These enable personnel to monitor and interact with equipment without having to be in a fixed location."

Ralph Rio, director of marketing at ARC Advisory Group, says wireless is neither suited to nor needed for machines. "Have you ever operated a machine?" he asks. "They run at high speed and are potentially dangerous. When someone bangs on the big, red, mushroom-shaped e-stop button, the machine needs to react immediately. People feel more secure with a hardwired interface. Technically, wireless would work, but it makes people nervous."

In addition, argues Rio, an operator does not need a lot of mobility while using the controls, so what is the benefit of a wireless OI for machines?"

Taylor agrees. "One factor may be that safety considerations necessitate an operator be in close proximity to the machines at all times," he explains. "The machines are more compact, and there is a need for an operator interface near the machines--all lessening the need for wireless operator interface terminals."

Both of them raise good points. Nevertheless, the analysts at Frost & Sullivan believe wireless is coming to the industrial machine business anyway. "In the increasing push toward lean production practices in the machine tool industry, manufacturing is migrating from closed, computerized numerical control (CNC) systems to more open systems, including commercial off-the-shelf (COTS) PC-based technology," explains Sath Rao, industry analyst at Frost & Sullivan (www.frost.com). "In fact, PC-based control systems are increasingly deployed in cell manufacturing topology for lean production initiatives, where one worker is managing several machines."

So, this seems to be an ideal environment for using wireless handhelds as HMIs, but Rao sees a problem, too. "Palm-based readers used in industrial networking systems need a noise-free environment," he notes. "Interference caused by electrical sparks and electromagnetic surges can cause data corruption. This is one of the reasons for the reluctance among managers in the machine tools industry to adopt handheld devices."

In Defense of Wireless

Dave Kaley, product manager at Rockwell Automation, sits on the other side of the fence. The company offers MobileView wireless OI that few machine builders want to buy, and he hears the same objections.

"Many of the companies that might benefit most from wireless today are reluctant to adopt the technology," he says. "While some plants are integrating wireless in gradual steps, others mistakenly believe there are too many problems with the technology, or that it costs too much to warrant installation."

Kaley says most machine builder objections involve fears of inconsistent reliability, low security, and high cost. He believes he has answers for each:

* Inconsistent reliability: "Primary concerns stem from how electrical noise and interference might affect the signal--no small issue in an industrial setting where physical obstacles and operating machinery could potentially block or distort a transmission," he says. "The fact of the matter is that, since wireless was first introduced, technological advances have solved most interference issues." He points out most wireless devices use IEEE 802.11b, which operates at around 2.4 GHz--a frequency that drastically limits the types of interference that can affect a connection.

* Low security: Because no wires are involved, and there regularly are news stories about hackers getting into wireless networks, machine builders are worried about security. "The introduction of technologies such as spread-spectrum techniques, encryption, and digital-packet switching add security and efficiency to wireless systems," says Kaley. "Our mobile terminals, for example, use wired equivalent protection (WEP), which is part of the 802.11b standard." WEP provides 128-bit encryption that is equivalent to the security provided on most wired networks. "Many other protection schemes can also be used and new solutions are being developed almost every day, adds Kaley.

Harry Forbes, analyst at ARC, agrees. "The security risk has been over-hyped," he says. "Though the existing WEP security is breakable, the highly publicized horror stories of security holes stem from access points deployed in modes where WEP and other security mechanisms were simply left unconfigured. Most major manufacturers have defined responsibilities and policies to prevent these situations."

* High cost: "Many companies assume the price of wireless technology is beyond their reach," says Kaley. "In reality, wireless is quite affordable. There are even some cases where a wireless solution costs a fraction of the same installation using wire and cable. Cabling costs can be quite expensive and, when measuring the true cost of wireless versus wire or cable, it is important to take into account not only the initial purchase price, but also the installation costs and annual maintenance costs for maintaining the wire."

Forbes maintains wireless HMIs are coming. "The most likely scenario is WLAN (wireless LAN) capability will penetrate from laptops to rechargeable factory-floor devices such as mobile HMIs, PDAs, and bar code scanners. In the longer term, many control systems embedded in manufacturing equipment will become candidates for WLAN connectivity."

Waiting in the Wi-Fi Wings

So, what developments will trigger wireless inroads? Higher speed, for one thing. In September, the IEEE began work on a standard that triples the rate of wireless LANs. The current speed of IEEE 802 wireless LANs is 30 Mbps, and the new standard--IEEE 802.11n--will take it to more than 100 Mbps.

Another development that has been anxiously awaited is the ZigBee protocol, developed by Motorola and based on IEEE 802.15.4. The standard makes it easy to develop wireless sensor networks, the first step to a wireless machine. Motorola says acceleration and pressure sensors with the ZigBee protocol are available, so machine builders can start developing wireless PDA-based vibration, bearing wear, and similar sensing applications for maintenance and reliability.

Tools for Transmitting

Machine builders wanting to dabble in wireless HMI applications might find it easier than they expect. First of all, some Pocket PCs and PDAs often support the same software that's in your PC-based HMI. So, if you base your HMI on a handheld device that runs Windows CE 3.0, for example, you may be able to use almost the exact same programs that you have in your PC.

You may have to cut some of the capability, because Windows CE doesn't support all the fancy graphics you might have in your Windows 2000-based HMI, and you can't quite show as much information on that tiny screen as you can put up on a 17-in. PC display, but these are not insurmountable problems.

Many of the HMI vendors probably have what you need to bring up a PDA. If you are currently using their HMI/SCADA software, it's probably a good bet that your software vendor can help you out.



In the machine building business, much of what we do is influenced by the European market. This applies to everything from safety regulations and ISO specs to using metric nuts and bolts. If you want to sell in Europe, you must go along or you'll get forced out of the market. Since Europeans tend to adopt high technology quicker than we do, it is in your best interest to watch what the Europeans are doing with wireless.

According to Frost & Sullivan (www.frost.com) analyst Gabriela Martinho, the European wireless technologies market for industrial applications is at the initial stage of development and remains highly fragmented, in terms of suppliers, applications and products. "Despite the strong growth expectations for this market for the next few years, wireless products on the factory floor have so far been embraced by innovators and early adopters rather than industry as a whole," she says.

Martinho has some of the same objections as the other analysts, plus a few new ones. "One of the main barriers to the adoption of wireless products is the existence of several open and proprietary wireless communications protocols," she says. "That results in end-user confusion and hesitance to commit to one protocol, which could later not emerge as the universal standard."

There's more. "Another factor delaying growth in wireless solutions is user skepticism," she adds. "Although most potential users within the industrial market are familiar with the concept of wireless communications, there is not much knowledge of real applications of the technology in the industrial arena." Overcoming user concerns about reliability and security is essential for suppliers of wireless solutions.

Martinho says wireless OIs are being used in Europe. "Wireless devices on the factory floor have been mainly used for monitoring of machinery, systems, and processes rather than for real-time control," she says. "This is due to concerns over security and reliability and the critical nature of data transferred."

The analyst suggests you keep an eye on your automotive customers, because they are likely to be big wireless users. "The automotive market is one of the industrial sectors with the highest level of investment in new technologies and lean manufacturing tools," Martinho says. "This sector is expected to be the fastest growing applications area for wireless technologies. The increasing need for flexibility and mobility of production lines and cells, along with the increasing use of wireless devices within vehicles should boost demand for wireless products."

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