Patent ID: 8258929

Claim:
A RFID printer, comprising: a RFID reader/writer; an index sensor configured to detect a leading edge of a RFID record member, the RFID record member including one or more RFID transponders; an antenna configured to emit a RF field and coupled to and cooperating with the RFID reader/writer to read and/or write to a RFID transponder; a printing system having a print head and a drive mechanism to drive a web of RFID record members past the print head for printing data thereon; a memory; and a processor, the processor coupled to the memory, the index sensor, the printing system, and to the RFID reader/writer and operable to encode and print on the RFID record member as the web continues in motion, the processor configured to perform the steps of: determining if the RF field is capable of encoding the RFID transponder at a selected continuous web speed, detecting the RFID transponder in a generated RF field, counting a number of steps the RFID transponder remains in the generated RF field, and determining a RF field length based on the counted number of steps wherein each step represents a physical distance; if the selected continuous web speed is too high to encode the RFID transponder, determining a continuous lower web speed at which to encode the RFID transponder; and adjusting the web speed to the determined continuous web speed to encode the RFID transponder.