I have a Nordic ID Sampo S1 reader and I'm trying to figure out how to deactivate a bunch of RFID tags simultaneously. My use case is as follows: A user picks up a couple of products from the shop, then places those products on the reader (10 items, for example). The reader then identifies all tags and provides their tag ID numbers.
How could I deactivate all tags at once? I vaguely understand, from your resources, that with an access password, a reader can deactivate or kill tags. But could the device deactivate multiple tags at once? Please help me clarify this—and also let me know if it is possible to do this with a Sampo S1 reader.
A passive UHF RFID reader can never communicate with more than one tag at a time. That being said, the reader communicates with tags very quickly, so it often appears that 50 tags or more are being read simultaneously.
To deactivate the tags, the reader would need to receive each tag's serial number, send a password to unlock the memory block where the kill command password is stored, and then transmit the kill command. This process would be repeated for each tag. With 10 tags, it could take a second or two to complete the process. With 100 tags, it would obviously take longer.
I hope that answers your question, and I hope to see you next month at RFID Journal LIVE! 2018.
—Mark Roberti, Founder and Editor, RFID Journal