Is there a long delay for a tag to begin responding to an RFID reader?
It takes only a fraction of a second for a tag to receive enough power to begin responding to a reader. If a passive tag has a sensor attached to it, it may take a second or two to get enough energy to power the sensor, but generally speaking, passive tags are interrogated so quickly that it seems instantaneous—even when there are multiple tags in the read zone and the reader must go through an anti-collision algorithm to communicate with each tag individually.
—Mark Roberti, Founder and Editor, RFID Journal
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