Patent ID: 7737822

Claim:
A method of recognizing whether a transponder designed for communicating with a communication station belongs to one of at least two groups of transponders under which method the communication station designed for communicating with the transponder delivers a request signal to the transponder, which request signal comprises a command data block and a CRC check data block, and under which method, data contained in the request signal is evaluated in the transponder in order to recognize whether the transponder belongs to a group of transponders, wherein, for each group of transponders, a CRC check data block that is significant for the group of transponders is generated, and wherein the data that is evaluated for the recognition of whether the transponder belongs to a group of transponders is data from the CRC check data block that is significant for the group of transponders; wherein the transponders process the command data block only if evaluation of the check data block of the request signal indicates that the transponder belongs to the group of transponders that is identified by the CRC check data block.