For example, the Low-Level Reader Protocol (LLRP) standard says the commands are queued. Are there any devices with a proprietary application programming interface (API) that could fulfill them simultaneously?
It would not be possible to simultaneously read a tag’s ID number and write to that tag. An antenna can only communicate with one reader at a time. The passive UHF Gen 2 RFID standard does allow for two sessions, enabling two separate readers to inventory tags. Reader #1 could communicate with a tag while it was in session A, then reader #2 could communicate with the tag once it switched to session B. However, I do not believe sessions would allow one reader to interrogate tags and another to write to them, because it would take more time and energy to write to the tag.
—Mark Roberti, Founder and Editor, RFID Journal
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