CODEWITHSUNDEEP
rfid
Westy
Westy

Reputation: 305

How Long is RFID Tag Session 2 Persistence?

When doing scanning with passive RFID tags, you can set the SESSION to '2' in order for the tag state of 'B' to persist for "an indefinite amount of time" even when it is not being energized by the scanner, according to the standards. Your tag will then not be visible to the scanner until this indefinite amount of time expires.

My question is, does anyone have any idea what the maximum amount of time is for RFID tags? I'm sure it's different for different tag manufacturers , etc. However, are we talking seconds, minutes, hours, or even days? I don't want to keep seeing the same tags over and over again while doing a scan in the storeroom, but at the same time, I don't want the tag to be hidden if they need to be scanned again at a later time.

Upvotes: 0

Views: 684

Answers (1)

Danny
Danny

Reputation: 466

The answer is: it depends. Please note that the standard says 'indefinite when powered'. When powered, it is really indefinite. When not powered, the standard defines it is longer than 5 seconds. For most modern tags, it is typically less than 30s, of course depending on environment conditions.

About the definition of 'powered': please note that this power can originate from any RFID reader, not only the one you are using to interrogate the tags with. Or any other radio device that transmits at the same frequency.

To circumvent this, you can use a SELECT statement to revert the session flag back from B to A.

Upvotes: 1

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