When Joe Kehoe chose a wireless application to gather information from a well that needs to be monitored by Tampa Bay Water in Clearwater, Fla., he made the wireless decision based on the cost and difficulty of running a cable. “I have two wells at a site, and we need to measure flow rate and run indication to make sure the wells are running,” explains Kehoe, instrumentation and control supervisor at the plant. “To do a simple wire run, I would have to go under a railroad and across 100 feet.” According to Kehoe, running wire under the track would be a tough proposition, both in terms of dollars and in resistance from the railroad itself.
In another instance, Kehoe uses a wireless system at a customer’s plant. His goal was to retrieve water quality signals for a hydrogen sulfide removal station. Running cable would have involved running conduit through the customer’s operation, then creating a cabinet to collect the data. The wireless solution allows Tampa Bay Water to place an analyzer right at the customer’s point of discharge, while sending the sensor’s data straight to Tampa Bay Water’s facility. No wires. No mess. No blurry lines of responsibility for conduit and cable.
Simple Math
Both of these instances illustrate a growth area for wireless applications in industry. These applications are incidental and the decision to use wireless devices is based on simple cost arithmetic. Going wireless doesn’t necessarily improve the function that a cable delivers, but it can certainly make specific point-to-point connections easier and cheaper. The logic is much like using a cell phone rather than a land line—there isn’t much difference in the function, but the absence of an awkward wire can be quite liberating.
“There is a whole class of products that are simply wireless cable replacement,” explains Harry Forbes, senior analyst at ARC Advisory Group Inc., Dedham, Mass. “It’s very opportunistic.” Forbes sees a growing number of wireless applications that show up like Kehoe’s need to get across the railroad tracks. “Manufacturers use wireless when they have a job where they have a small thing to add and there are a lot of costs. If they can get point-to-point wireless applications and it’s inexpensive enough, they use it.”
Other areas of wireless connectivity actually deliver new functionality for manufacturers. Radio frequency identification (RFID) offers up promises of “perfect inventory visibility.” By tagging a product, truck or padlock with an RFID device, the user can see where that item is at all times. The small tag contains a silicon chip with unique data and an antenna that sends out the information. As a tagged product passes from truck to dock to shelf, every item can be counted. And if a truck begins to move while the driver is inside a motel sleeping, somebody knows about it.
RFID can add considerable accuracy to warehouse operations. When Chicago-based electronics distributor Newark InOne equipped its warehouse and transportation systems with RFID technology from Manhattan Associates, Atlanta, the company gained the ability to pull and count orders without scanners. All of the company’s trucks are now outfitted with RFID. “Our dollar accuracy is now around 99.2 percent,” notes Kevin Deaton, Newark’s director of transportation. “And our location accuracy is 98.5 percent.” According to Deaton, Newark will recover its $500,000 investment in RFID within three years.
According to Bob Parker, industry strategist at AMR Research Inc., Boston, wireless applications for manufacturers fall into three basic categories:
1. Data transmission of fluid levels or sensors that monitor equipment for maintenance purposes;
2. Part or asset tracking; and
3. Manufacturing applications delivery, which includes wireless local area network (LAN) technology.
“The applications investment has been outside the plant floor,” says Parker. “Manufacturers have opted to put wireless applications access into field services and sales.”
的技术可以提供最大的一ll benefit is RFID, notes Parker, which he includes in the part and asset tracking category. “The RFID tags are being used in everything from aerospace and defense to consumer packaged goods,” he observes. “That could change how we think about software for manufacturing. If everything has an RFID tag, you won’t need to track all of your transactions to know your balance.”
Applying wireless
Overall use of wireless technology may fall into three major groups, but in the actual manufacturing activity, wireless technology is being used for a number of individual functions, from tracking labor to instructing workers on the plant floor. Here are some current uses for wireless devices on the plant floor.
Sensor monitoring or malfunction detection. Wireless is increasingly used for cable replacement. “We’re trying to eliminate wiring in the control of process manufacturing,” says Davis Mathews, product manager for wireless devices at Phoenix Contact Inc., Harrisburg, Pa. “It’s difficult and expensive to run conduit and cable to a flame detection system in petrochemical processes,” explains Mathews. “Wireless eliminates that expense.”
Equipment wear monitoring. If a part will eventually give out and bring a plant to a halt, it can be useful to monitor that part closely so it can be replaced before it malfunctions. “Under normal conditions, wireless connectivity is used for reliability centric maintenance,” says Dennis Gaughan, research director at AMR Research. “It lets you look at a reading of the equipment to indicate planned preventive maintenance.” He notes that the costs of wireless sensors have become reasonable.
劳动跟踪。Lyco制造业Inc .开发turer of food equipment in Columbus, Wis., has taken wireless computer connectivity down to its shop floor to track labor. “We have four terminals with touch screens that we use for labor data collection,” says Kim Archambault, who is in change of systems, production and inventory control at Lyco. As the labor information is entered, it is sent via a wireless system, produced by Guardian Business Solutions Inc., Brookfield, Wisc., to Lyco’s enterprise resources planning (ERP) system. “Before the wireless collection, we used manual cards,” says Archambault. “Now we take the touch screen to the manufacturing spot, put in the information and send it back to the manufacturing system.”
Machinery control. Lyco is also bringing wireless technology to its manufacturing equipment. “We’re converting a punch press to a computer-controlled system, and we will use wireless for that as well,” says Archambault. “Instead of running wire, we’re going to have the punch tap into our Cisco System, and we’ll tell it how to punch the material,” explains Archambault. “In the manufacturing environment, it’s easier to put on an antenna. It would take eight to ten hours to run the wire.”
Mobile computing. Guardian also produces a wireless product called ShopTalk that allows a manufacturer to set up a computer station anywhere on the factory floor. “We have a mobile computer that ties into a company’s ERP system and can bring up digital pictures or movies on how to set up a work center,” explains Bob Lazlo, Guardian’s director of sales and marketing. Lazlo notes that computers on carts are connected without wires to allow companies to track manufacturing as it moves across the shop floor. According to Lazlo, the mobile computers are particularly useful in industries such as aerospace, in which the manufacturing process is not fixed in one place.
AMR’s Parker notes that sometimes it is easier to move a computer than it is to move the manufacturing equipment. “You may have a plant floor with computer centers here and there,” says Parker. “With a wireless LAN, you don’t have to rewire the plant floor every time you reconfigure.”
Wearable computers. Another wireless solution comes in the form of a computer that can travel with the worker. “The wearable computer can do quality control,” explains Lazlo. “You can point out your quality defects and it goes into engineering or a work center that is supposed to fix it.” The wearable computer can also guide a worker through a series of tasks. “We use a voice prompt that allows workers to validate what they’re doing,” explains Lazlo. “This saves them from having to go back and forth to the computer.”
RFID–Intelligent Inventory. At Corporate Express Inc., a Broomfield, Colo., office supply company, an employee uses a wearable computer to tell pick-and-pack workers where to get the next item to fill a customer’s order. The items are mapped by RFID. “We download the orders from our warehouse management system, and it operates the voice that tells the employee which location to go to,” explains Tim Beauchamp, senior vice president of distribution operations. The system has an RFID backbone for stock location. As the picker chooses an item for the customer, it is matched and checked off in the order management system. The result: improved accuracy and efficiency. “Over paper-based, it’s easy to get 100 percent productivity gain, but the biggest benefit is an improvement in quality,” says Beauchamp.
The wireless future
Part of the argument on behalf of wireless applications is their potential cost savings. As companies become more accustomed to the use of wireless, and as costs come down, companies are more inclined to adopt the technology. “When our first customer, Alcoa, started using wireless, it was an experiment,” says Phoenix Contact’s Mathews. “Now it has become a conscious choice for them.” He notes that some of his customers say they’re reluctant to try it because it’s new. “And yet, they’re talking to me on a cell phone,” Mathews points out. “There is some hesitation,” he concedes. “But wireless will become a dominant technology because it offers real efficiencies.”
