5 Key Factors for RFID Success: Hardware and Tag Considerations 

While it’s relatively easy to find and implement good RFID software to help you manage and track all of your inventory and asset data and locations, your RFID hardware and tags will determine whether you’ll capture all of that data properly in the first place. Your hardware and tags must work together to detect, identify, and locate every asset in your unique environment and given your specific use case needs.   

This is why it’s so important to conduct site surveys and perform pilot tests, to help you assess your environment, identify the right RFID hardware and tags for the job, and validate that they’ll work for your applications and environment.   

At SK&T, our RFID and data capture experts do this for every RFID implementation, working with our clients to make sure that we specify, test and validate the right solutions for each application.   

In this quick article, we’ll take a look at some of the key factors we keep in mind when evaluating and choosing the right RFID hardware and tags, and we’ll provide examples of technologies and solutions that can help you get the ideal results.   

Key Hardware and Tag Factors to Ensure RFID Success 

1. Active vs. Passive RFID Tracking

Arguably the biggest determining factor in any RFID implementation is the type of tracking you need to do and whether it requires active or passive RFID tags. 

Passive RFID tags are the most commonly used and are the least expensive. They rely on an RFID reader, which sends them a signal to wake up and uses the energy of the RF signal itself to provide power to the tag. This way, the tags can communicate with a nearby RFID reader, which detects their identity and location.   

  

Active RFID tags are required in any use case where you need real-time updates or long-range reads and locating for your tagged items. 

With active RFID, your tags wake themselves up at regular intervals and power themselves with a tiny battery in the tag, which allows them to take a more “active” role and communicate with nearby readers at time intervals that you specify. Active RFID tags also provide a much longer range to transmit signals, with ranges of up to 325 feet (100 meters) or more, compared to ranges of up to 50 feet (15 meters) for passive RFID.   

Active versus passive RFID tracking requires different RFID readers, antennas and infrastructure. Active RFID systems rely on fixed-position RFID readers to communicate with tags, but you can readily use handheld RFID readers with passive RFID tags.   

Active RFID hardware is much more expensive than passive RFID systems, so this is a crucial factor for many organizations. Many only choose active RFID if the value of the items and assets they’re tracking justifies the cost, or if the savings from automating their tracking and locating and moving to real-time insights means it makes good financial sense. Otherwise, passive RFID may be the only affordable option, but if you need real-time tracking or long-range RFID reading, then passive RFID isn’t a viable option.

2. Tracking Items on the Move or at Rest 

Another big factor in achieving RFID success is making sure that you understand the different tags and hardware you might need if you’re looking to track items on the move vs. at rest.   

If you’re just tracking and locating tagged items at rest, such as tracking and managing inventory in a warehouse, then a passive RFID system with UHF tags might be all you need, and you can read those tags with a handheld or fixed reader, depending on your needs or preferences. For example, a warehouse worker can simply walk an aisle with a handheld RFID reader and automatically detect and locate large numbers of RFID tags on shelves, transmitting all of that data to your RFID software and business systems.   

However, if you need to track items on the move, such as identifying and locating items that are moving on a conveyor or through a dock door, then you will need fixed RFID hardware such as fixed RFID portals or tunnels that you install at key checkpoints or locations. As items pass through these portals or within range of their fixed RFID readers, their identity and location can be collected and the resulting data transmitted to your RFID software and business systems.   

To get the right results, you’ll need to match up the right hardware and tags with the type of system you’re using, the volume and density of items you need to track, and the right system design to make it all possible.  

3. The Liquid and Metal Factor  

Historically, two of the biggest challenges for RFID have been liquids and metals. If you need to tag and track metal items or those containing liquids, or if there is a high volume of liquids or metals in your environment, this can pose problems.   

Liquids tend to absorb wireless RFID signals, and metals are known to reflect and detune them, so you can end up with poor read rates or read failures, and your read ranges might be dramatically shortened. It’s especially challenging when using UHF RFID tags, which are the industry standard and most cost-effective for most RFID applications.   

In the past, you could compensate for these limits by using high-frequency (HF) RFID tags. These provided better read rates and reliability, but their read ranges were only around three feet (one meter).   

Fortunately, advancements in UHF RFID technology have helped break through these limitations. For example, Zebra’s Silverline RFID tags provide read ranges of up to 12 feet (3.5 meters) on metal and 7 feet (2 meters) on liquids. That’s a huge improvement because it more than doubles or can even quadruple your potential read ranges, depending on your environment and application. It also helps ensure much better read rates and reliability, so Silverline tags are highly viable in many current RFID applications. 

 

If you need to track liquids or metals, or you’re operating in an environment with an unusually high density of them, then you need to pay close attention, choose the right tags, do a thorough site survey, and perform pilot tests. This will help ensure that you can get the right results with your RFID implementation. 

4. Tag Density and Volumes  

One frequent challenge with UHF RFID systems is that signals from readers can potentially interfere with each other, especially where their coverage overlaps, you’re using different types of readers, and you’re working with a high density of RFID tags in your facility.   

This problem is called reader collision, and it typically occurs when multiple RFID readers are deployed or in use nearby. In this situation, signals that your tags are supposed to receive can be picked up by another nearby reader, leading to inefficiency and errors in RFID data collection and transmission.   

Fortunately, RFID tag technology has evolved and solved this challenge by using something called Dense Reader Mode (DRM). This is a channel-hopping method that allows readers to avoid interfering with other readers. Readers hop between channels within a certain frequency range and will often listen for a signal before using a channel. If they detect another reader using that channel, they’ll go to another one.   

In many situations, and especially if you’re going to have a sizable volume and density of tags potentially being read by multiple readers that could overlap, make sure that your RFID readers are EPC Gen-2 compliant and offer Dense Reader Mode.  

5. Cost Considerations  

As we touched on in our earlier discussion of active vs. passive RFID tags, a huge factor that can make or break your RFID implementation is cost. In fact, it might determine whether you can adopt RFID at all or whether you need to look at other alternatives such as Bluetooth low-energy beacons or even barcoding systems.   

RFID is not cheap to implement, but the return on investment can be huge, so it’s always important to weigh the total long-term cost of your potential system against the gains you can expect from automated tracking, better accuracy, and having better visibility into the inventory or assets you’re tracking, and the value this information can provide to your business.   

In many cases, RFID can slash the time to conduct inventory counts from days or weeks to minutes or hours; it can save hundreds of thousands of dollars in labor, time, and related costs in managing and tracking your inventory; and it can create huge savings by helping to avoid the loss of high-value and expensive assets or inventory.   

However, you still have to compare this to your up-front and long-term costs, and, even if the business case is clearly there, you still need to do your due diligence to perform site surveys, pilot tests, and a proper hardware and tag implementation, to help ensure that you achieve those desired results.   

To get started, just reach out to our RFID experts at SK&T, and we’ll be happy to help. As RFID, data capture, tracking and locating specialists for nearly 30 years, we’ve been on the forefront of RFID technology since its inception, and our systems engineers and technical specialists would be glad to set up a free consultation at your convenience.   

Just call us at 720-851-9108 or contact us online, and let’s get to work on ensuring your RFID project’s success!