Abstract: An RFID reader system has an RFID tag and an RFID reader. The tag authorizes the RFID reader by receiving a plurality of successively-transmitted initial RFID read signals and determining respective initial-read signal power levels of the received initial RFID read signals. Using the determined initial-read signal power levels, a controller automatically selects an authorization sequence. A plurality of successively-transmitted authorization RFID signals are received sequentially, and respective authorization-signal power levels of the received authorization RFID read signals are determined. The determined authorization-signal power levels are automatically compared to the authorization sequence using the controller, so that the RFID reader is authorized if the determined authorization-signal power levels correspond to the authorization sequence.

Abstract: A method of verifying the identification of fluids to be supplied successively through a fluid-supply hose that selectively connects to successive movable, RFID-tagged fluid containers includes providing an RFID reading unit including an antenna. A sequence of reference container identification codes is received. A container-present indication indicating one of the containers is positioned so that its RFID tag is in the antenna range is received. In response, the RFID tag of that container is read using the RFID reading unit to determine an identification code of the container. A controller automatically verifies the determined container identification code against the first reference identification code in the sequence using a controller. The starting through verifying steps are repeated, using successive values from the sequence in the verifying step, until all values in the sequence have been verified against container identification codes read using the RFID reading unit.

Abstract: An RFID reader system has an RFID tag and an RFID reader. The tag authorizes the RFID reader by receiving a plurality of successively-transmitted initial RFID read signals and determining respective initial-read signal power levels of the received initial RFID read signals. Using the determined initial-read signal power levels, a controller automatically selects an authorization sequence. A plurality of successively-transmitted authorization RFID signals are received sequentially, and respective authorization-signal power levels of the received authorization RFID read signals are determined. The determined authorization-signal power levels are automatically compared to the authorization sequence using the controller, so that the RFID reader is authorized if the determined authorization-signal power levels correspond to the authorization sequence.