The reader will transmit a RF trigger pulse to activate (turn-on) the transponders. After a time delay, the reader then will transmit an encoded signal, referred to as the polling message which, upon detection and decoding by the transponder, will provide initial information to the transponder including the type of transaction the reader wishes to conduct.

The reader will then transmit an unmodulated CW.RF signal for the transponder to modulate with a data message while backscattering to the reader. The reader may repeat the polling-to-backscattering sequence until it obtains an error free data message from the transponder. The reader will then transmit an encoded acknowledge message to the transponder providing status information and requesting that the transponder not respond to the same polling message again for a fixed time period.