Why Won’t My RFID Reader Interrogate Some Tags?

By RFID Journal

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Ask The ExpertsWhy Won’t My RFID Reader Interrogate Some Tags?
RFID Journal Staff asked 10 years ago

I am using a low-frequency (LF) reader to interrogate LF tags that I have received from different companies, but it can only read some of them. Is there a reason for this?

—Name withheld


There could be several reasons. The tags could be using a different frequency, and might not actually be low-frequency. An ultrahigh-frequency (UHF) reader cannot communicate with high-frequency (HF) tags, for example, and vice versa.

They also could be utilizing different air-interface protocols. There are a variety of standards established by the International Organization for Standardization (ISO) for radio frequency identification systems. For HF, there are ISO 14443, ISO 15693 and ISO 18000-3. For passive UHF, there are ISO 18000-6A, ISO 18000-6B and ISO 18000-6C. If you have some tags based on ISO 14443 and some based on ISO 15693, and you have an ISO 15693 reader, then you would not be able to interrogate the ISO 14443 tags with that device.

Even if tags employed the same air-interface protocol standard, it is possible that you still might not be able to read every tag from every provider. Manufacturers implement the standards in slightly different ways, and very little conformance testing is conducted in the RFID industry to ensure that a reader complying with one standard can interrogate all tags based on that standard. As the industry grows, this could become a bigger issue, so I would expect that conformance testing will soon become more common.

—Mark Roberti, Founder and Editor, RFID Journal

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