Are passive tags recyclable? With read-write chips, can information be added to the tag, or be written over existing information when the tag is within range of a reader?
With most RFID tags, you can write data to them, assuming they have read-write memory, using software supplied with the reader. Alternatively, if you need to write data to a large number of tags, you can utilize third-party software that will bulk-encode the tags. The Electronic Product Code (EPC) standard for passive ultrahigh-frequency (UHF) tags allows you to write a single 16-bit "word" to the chip's memory. The Block Write command lets you write multiple 16-bit words. In order to Block Write to the tag, both the tag and the reader must support the Block Write command. If you want to write over existing data, you can do so with the same commands, provided that the memory was not locked the first time data was written to the tag.
Passive tags can be recycled if they are encased in protective plastic or some other material that will allow them to survive the removal process. If you try to tear a passive RFID label off an object, you will likely destroy the connection between the chip and the antenna, thereby rendering the tag useless. You also will not be able to stick the label on anything else. But there are tags encased in plastic that can be affixed to totes that make multiple trips through the supply chain, or that can be affixed to assets via a plastic loop. Additionally, you can obtain hard tags that can be affixed to clothing and reused, much like how electronic article surveillance (EAS) tags are recycled.
The challenge with reusing tags is managing the collected data. You must ensure that when a tag is removed, its serial number is no longer associated with the item being tracked, and that it is properly assigned to a new object. If you are doing this for thousands or tens of thousands of items, that can prove challenging. Therefore, proper processes and controls must be established in order to ensure that each tag is associated with the correct item, every time.
—Mark Roberti, Founder and Editor, RFID Journal
Previous Post Where Can I Find a Passive UHF RFID Reader That Employs RSSI? »