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RFID system are a number of components including tags, handheld or stationary readers, antennas, and system software. A reader is comprised of a transmitter, receiver, control module and a communication function, sometimes called a transceiver in radio terms, for it to link to a controlling PC or PLC.
Tags are used to identify objects, which can be uniquely programmed with information about the objects. A reader should have an attached antenna, which is used to transmit and receive the RF signal. Each reader is accompanied with software that allows the user to read and program tags. Serial (RS232 or RS422/485) or Ethernet are the typical communications methods, though others are available.