Say, for instance, that one wanted to monitor the state of a device, and that in the event of some sort of failure, the tag would be changed so that when it was read, the failure would be identified. Is this possible?
Yes, it is possible. I have seen two ways that it can be done. One way to get information about the state of a device would be to create an antenna that would break if the device failed, or if something else occurred. The breaking of the antenna would make it impossible to read the tag, and the lack of a tag read would thus indicate a problem.
There are passive Near Field Communication (NFC) chips from NXP Semiconductors and passive ultrahigh-frequency (UHF) chips from NXP, Impinj and other companies that have an input-output port. This allows you to wire that passive UHF or NFC chip into another device. Signals can be transmitted from the RFID transponder to the device, or from the device to the chip. This is most commonly used in temperature sensors. When a temperature threshold is exceeded, that information can be sent to the transponder and stored on its chip so that the next time the tag is read, you would receive that data.
It should be possible to use this system to indicate the state of a device or its failure.
—Mark Roberti, Founder and Editor, RFID Journal
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