So you tried RFID, and it was a bust.
But why? Is it worth another attempt?
Radio-Frequency Identification (RFID) is both simpler and more complicated than many think. To successfully deploy RFID in your business, there are a lot of factors you need to take into account and best practices you need to follow. Miss a key area, and your project could fail—but if you learn from the problem and try again, you may find that RFID tracking is the perfect answer for your inventory and asset management issues after all.
How does it work?
Before we go over the common problems with RFID deployment, it’s worth going through a quick refresher on how RFID actually operates. Misunderstanding the technical side is the cause of a lot of common issues, so getting the specifics clear upfront may save you a lot of time.
There are three key components to a fixed RFID system: readers, antennas, and tags.
Readers are perhaps confusingly named as they don’t actually ‘read’ anything themselves. Instead, they process the data picked up by the antennas and send it on to the connected server. A fixed reader will generally be hidden from sight in a cabinet, wall, or ceiling, and is usually wired into your network with ethernet cabling. Some readers can also send data wirelessly using WiFi or a mobile data connection. Depending on the reader, you could have up to eight antennas connected with special coaxial cabling.
Antennas send out radio signals to activate the tags and receive the data back in return, which they pass to the reader for processing. The best antenna for the job is dependent on the deployment environment: you’ll need to make sure you have enough antennas, angled correctly, to cover the entire intended chokepoint. Usually, one or more antennas will be tied to a ‘location’ in your RFID tracking software.
Handheld readers are smaller and portable, with both a reader and an antenna built in. Typically they’ll take the form of a sled with a trigger grip, on which you can mount a smartphone-sized device to run tracking software. There are other types of mobile readers, but these are the most common.
Tags are labels, typically made from paper, foam, or plastic, with a microchip and a tiny radio antenna built in. When the signal from the larger antennas hits the tag, the tag’s antenna will activate and send back the data contained in the tag’s chip.
Here’s an example of a fixed reader and four antenna installation in the wild, from one of our customer case studies. Tags on pallets passing through this gap will be detected by the antennas, and the reader will send the tag data on to the RFID tracking software on the cloud servers.
Now that we’re confident with our terminology, let’s look at some of the common issues that arise in RFID deployments and how you can avoid them.
If you had the wrong kind of tags …
Not all RFID tags are created equal: you’ll need to take into account the material the tag is going on, your durability needs, and the general environment.
Need help choosing your tags? Click here!
RFID and Metal
Radio signals can’t travel through metal—they’ll bounce straight off. This makes it trickier to tag metal or metal-containing items. Fortunately, there are special foam tag ranges available that provide the insulation needed to make the tag’s internal antenna function correctly. For example, Zebra’s Silverline Blade II is specifically designed for use on metal and metal-heavy objects (like IT equipment).
Unfortunately, even the best on-metal tag won’t help you in the tag is inside a metal box as it passes an antenna. For a RFID tracking system to function correctly, your workflows need to be built around making sure that you give the antennas the best chance of seeing the tag. In the sample four-antenna chokepoint setup shown above, you’d want the tags to be placed on the sides of the pallet, and have forklift trucks consistently pick up the pallets in the correct orientation so that the tags pass the antennas unobstructed. That way, even if the pallet was stacked high with steel, the tag itself would still be seen and the tracking software would update as planned.
RFID and Liquid
Liquids absorb radio signals, so you can’t scan through them. This means high-liquid environments require us to get creative. There are all kinds of specialty tags designed for the purpose (eg. tags for wine bottle necks).
If you’re trying to tag items containing liquid, we recommend you book a free consultation so we can get a sense of the specifics and help you through the testing process to find the tag that’s right for you.
Size (and Shape) Matters
The bigger the tag, the bigger the antenna in it—and the better the read range. If you’re having trouble getting antennas to pick up the tags in otherwise ideal circumstances, you might need to consider a larger tag.
If you need a tag with a larger antenna, but the item you’re tracking is too small to fit it, not all tags need to be fully attached to an item—you could use a flag or loop tag to separate the antenna from the item. Common use cases often have special tag designs: you can buy loop tags made specifically for jewelry, for example.
Click here to view our standard tag catalogue—or, if you need something more specialised, click here for a personalised quote or recommendation.
Rugged Tags
If you need a tag that’ll take some punishment, the Ironside and Viking tag ranges are designed with varying levels of durability, water resistance, and heat resistance. Contact us with your requirements and we can arrange to send samples for you to put through their paces.
Active Tags
So far, we’ve only discussed passive RFID, which relies solely on power emanating from the main antenna(s). Sometimes, though, it’s worth considering active tags, which contain a battery and run off their own power rather than absorbing it from the antenna. This significantly boosts the tag’s read range.
If you used a handheld reader …
Handheld RFID readers are a brilliant tool for easy stock and asset management, but it can take a little practice to get the hang of proper scanning technique. Here are some tips and common pitfalls:
- Make sure the reader’s power settings are set correctly.
If you’re scanning at range, you want all the power you can get. If you’re trying to scan a single tag with no interference, you want the power at minimum. Our RFID Asset tracking software allows you select the power level you need during stocktakes and asset searches so you can find what you need. - Make sure you’re scanning around potential obstructions.
Remember, RFID doesn’t like metal or liquids; and even less dense materials can cause problems if there’s enough of them. If you’re conducting a stocktake of tagged stock on a shelf, don’t just stand in front of the shelf and wave the antenna: get right up in there and to the back of each shelf, moving the reader around to get as many angles as you can. It’s still far quicker than a manual count, and you’ll get far greater accuracy. - Build your stock storage around RFID.
Take tag visibility and clear access into account when you’re arranging your stock: aim to have tags on the top or front of boxes, don’t over-stack, and make sure metal racking isn’t blocking any tags.
If you need advice on how to best to work with handheld readers, book a free consultation—we’re happy to help!
If you used fixed readers and antennas …
Fixed readers are a fantastic way to automate your processes and eliminate human error—but, of course, you need to set them up correctly first. Some common causes of performance issues are:
- Not enough antennas / antennas at the wrong height or angle.
Correct positioning requires careful testing. The TEC-RFID team conducts site surveys prior to every installation to determine exactly how many antennas you’ll need and the exact position necessary to cover exactly the right area. Post-installation, we tune the antennas’ power levels to make sure you’re scanning a far enough range—but not too far! - Wrong antenna polarization.
Many antennas have linear wave polarization, which can be very long range, but requires more careful tag positioning as it has a narrow read zone. Circular polarization ensures a wide read zone, which makes it good for scenarios where you can’t control tag positioning as closely—but the tradeoff is a shorter range. - Poor quality cabling.
Not just any coaxial cable will do: for best results, you’ll want specialty antenna cabling to minimise data loss. You’ll also want to make sure none of the cables are too long, for the same reason—we aim for a maximum of 15m in our installations.
If you need advice on a new fixed reader deployment, or improving an existing setup, book a free consultation with our expert team.
If your software didn’t fit your needs …
The best hardware in the world won’t help you if you can’t do what you need with the resulting data.
Asset Tracking
Our RFID Asset software is designed to work with handheld readers or fixed readers (or both!) to make managing your business assets quick and easy. We’re constantly improving performance and adding exciting new features.
- Location-based stocktakes let you make sure everything’s where it’s supposed to be.
- Locate hard-to-find tags with the Geiger-counter-style Find Asset tool.
- Easy mass-update of asset statuses or locations.
- Automatic location updates from fixed readers.
- Web portal for easy reports and data analysis.
- Flexible custom fields so you have all the data you need.
- Location-based alerts.
- User activity logs.
- REST API available.
- Google Sheets integration for custom reporting.
Partner Software
If RFID Asset isn’t the best fit for your needs, we also have resale agreements with other innovative tracking software providers. Contact us to explain your use case, and we can work together with our partners to design a system to your exact needs.
Ready to give it another try?
If you think your business could benefit from RFID, we’d be excited to help you set up a system that’ll meet your asset and inventory tracking needs. Click here to book a free consultation, or click here for more information on our RFID services.