Selecting RFID Tags

If only purchasing passive RFID tags were as simple as looking for the best price, or the “Gen 2” label. The reality is that your tag purchase will be far more complicated than that for the foreseeable future – if you do it correctly.

First of all, do not assume that a tag and a label are the same thing. There are several different categories of finished, passive RFID tags:

• Labels – typically are affixed to corrugated cardboard, paper, or plastic.
• Laminated cards or cardboard tickets – are usually carried by a person.
• Plastic injected molded tags – these can address an number of applications, including rugged environments and metal mounting issues.

Supply chain RFID tags require low-cost disposable RFID tags that typically replace barcodes. Supply chain tags have no power source and harvest radio waves as energy. This harvesting of radio waves allows them to build enough energy to transmit their ID (barcode) via radio frequencies to nearby radio receivers (RFID Readers). This type of tag is typically called a passive RFID tag. Supply chain tags have a useful life of one day to several years.

Asset RFID tags are disposable (supply chain) RFID tags that have been ‘hardened’ by encasing them in plastic or rubber coatings to survive repeated exposure to a wet, cold, or metal-mount environments. Asset tags need a minimum of a five year life span. Typical uses for asset tags include manufacturing processes where reused containers require careful monitoring, wash processes in food processing, or automatic notification of asset return or checkout.

Most people have no idea how much engineering goes into the design and manufacture of an RFID tag. A great deal more than just volume determines price. There are so many variables that affect price and, more importantly, performance. If you plan to purchase more than a few hundred tags, it's in your best interest to understand that tags are not created equally.

While RFID tags have read/write capability (you can change the ID / data on the tag ‘electronically’) there are few processes that should ever change the RFID tag data. PC’s ‘decentralized’ data processing in the 80’s and networks have re-centralized data processing. The same concept can be applied to tags. While a local tag could have it’s data stored directly on it -- the future of RFID tags / tag data will be merely as beacons into a central database. Central databases will store the complete tag history and data. The advantage of a central WIP (Work In Process) system where tags are the ID and the central system decides on the action is the next logical step.