Magazine Article | February 1, 2006

Do You Have The Right RFID Readers?

Source: Field Technologies Magazine

When implementing an RFID
(radio frequency identification) solution,
you must select the correct blend of
fixed, vehicle-mount, and handheld
RFID readers for your needs

Integrated Solutions, February 2006

For the sake of this article, let's say your company has decided to implement RFID, either for a mandate or to gain some automation in your warehouse and/or manufacturing environments. You and your team have researched the technology, developed a business plan, and made the case to receive the funding. Now, you're ready to implement, but you're facing an assortment of RFID products that make up a solution – products whose successful integration determine your project's success. RFID readers can make or break your project, and you need to know the best ways to implement the multiple types of readers out there.

You first need to determine where in your DC (distribution center) or manufacturing facility you want to take reads of RFID data. Read redundancy is essential, so you'll need multiple read points. However, you don't want to interrupt the natural movement and flow of materials. Hence, the best way to determine these points is to do a time-and-motion study of the facility's processes. You should be able to identify points in your facility that all goods pass through or by, such as dock doors, sections of conveyor belts, and shrink-wrap stations.

Some RFID readers merely activate tags and collect data; they require additional software to perform more advanced functions such as filtering data and sharing it with back end systems. "Hidden reader software costs may go undetected when initially buying RFID readers," says Jeff Jacobsen, president of RFID reader provider AWID. "Determine whether readers you're considering have middleware already integrated, or if you'll need to purchase additional software. This software can cost an additional $20,000 to $30,000 beyond the reader price."

So-called intelligent readers have middleware already integrated in them and can collect RFID data and send it to your WMS (warehouse management system) and/or ERP (enterprise resource planning) applications. Intelligent readers also can externally verify good and bad reads, so workers can take action to reapply a bad tag. A lightstack, which looks similar to a stoplight, can light up green for good reads or red for bad reads.

The real benefits of RFID come from sharing data – knowing exactly what products are where in the supply chain and how long they've been there. "Companies should make sure middleware, whether included with the reader or purchased additionally, can integrate with the middleware of their trading partners," says Jacobsen. Big names like SAP and Oracle are likely suspects for ERP systems you'll need to integrate with; other trading partners likely use homegrown, legacy software.


Fixed readers are those that, as the name suggests, are installed in specific points throughout a facility and do not move. The most typical fixed readers surround dock doors and read tagged product passing in or out of a facility. "Companies implementing RFID merely to meet mandates, and that don't want to integrate RFID into their businesses any more than they have to, will most likely be satisfied with fixed readers," says Mike Fisher, RFID business development manager at RFID solutions provider Intermec Technologies.

A setup like this works when companies are shipping a small amount of SKUs (stock keeping units) to a trading partner, either for a mandate, as Fisher suggests, or as a pilot project to get started with RFID. "Portal readers work for companies shipping, for example, 4 out of 4,000 SKUs to a retailer," says Michael Smith, RFID business development manager at RFID reader provider LXE, Inc. "There may be 100 dock doors, but only a few need to be outfitted with readers. If a company moves toward tagging all 4,000 SKUs, they need to find an additional way to read tags."


In your DC or manufacturing facility, you probably rely heavily on forklift trucks to move product around. By placing RFID readers on those trucks, you can read tagged items without interrupting your business processes. "Companies have developed warehouse processes over the last 25 years while using bar codes," says Smith. "It makes sense for RFID data collection processes to mirror that and to follow the flow. Readers on fork trucks – which must pick up cases anyway – can collect data without the loader needing to do anything. In the case of a full pallet move, you're taking 15 seconds out of the process for data collection (that's approximately how long a scan would take with a tethered bar code scanner). If you make 100, 200, or several thousand such moves, you're talking a real time savings. There are opportunities for reduced labor and increased speeds of product moving through the warehouse."

Four antennas can be linked to one reader, so you can put antennas in a few different places on the vehicle to optimize the automation of picking a pallet. Antennas can be placed between the forks to read a floor location tag or shelf tag, and you can place antennas on the front of trucks and the top of trucks to read the case. You can also use side-mounted antennas to verify that drivers are in the right locations.

Vehicle-mounted readers require more customized work because of their metal construction and moving parts. "Each installation becomes a custom engineering project," says Fisher. "Every time I look at a forklift installation, I know it will involve us as a technology vendor, the end user, and a local forklift dealer or integrator. Integrated RFID readers aren't supported by forklift manufacturers yet, but they might be soon."

Vehicle-mounted RFID readers can also verify case quantity, which eliminates mistakes made by human error. For example, if a warehouse employee is instructed to pick 10 cases of product X and 20 of product Y, he might lose count while picking the cases and building the pallet. That mistake won't be discovered until the shipping stage, when other cases have been added and the pallet is built, or even when the pallet is received by your trading partner. With RFID readers on the forklifts, the readers can serialize each case tag and keep track of how many are loaded. The reader, linked with the WMS, knows how many cases are needed, and if an extra case is added or if there aren't enough, a lightstack can be lit or horns can blow.


Handheld readers are primarily used for exceptions, since you'll have established fixed read points throughout your warehouse processes. "You can't always bring items past the fixed readers, so you need to be mobile," says Fisher. "If an item is lost, or you're doing asset inventory tracking, workers can program a tag number into a handheld reader and walk around with it, reading tags, until it beeps that the tag has been found." Handheld RFID readers aren't the type of readers that your RFID solution should solely subsist on.

The ideal situation is to have a blend of all three types of readers. Vehicle-mount readers can help you maintain existing processes and add accuracy to picking operations, fixed-mount (portal) readers can verify reads taken during picking, and handheld readers can be used to find lost items. "Depending on the business a company is in, some readers will be used more prevalently than others," says Smith. "For example, if a warehouse is heavily automated, there will be a majority of fixed readers. CPG [consumer packaged goods] companies make heavy use of vehicle-mounted readers."

Finally, RFID is evolving, and second-generation specifications (Gen 2 specs) are right around the corner. These new specs can affect how your RFID products work together and what new products are available as you upgrade. Ask your vendors whether their products are Gen 2 upgradeable so you aren't left purchasing an RFID solution all over again.