Patent ID: 7669767

Claim:
A tag access control system that controls data communication between a plurality of the reader/writers and one or more IC tags within a radio communication range of an antenna held by each of the plurality of the reader/writers comprises: a command accepting portion that accepts a command indicating an instruction to write data in the IC tag or an instruction to read data from the IC tag; a division portion that generates a plurality of divided commands for executing an instruction indicated by the accepted command; a parameter recording portion that stores a parameter for controlling the data communication by each of the plurality of reader/writers, a parameter change portion that changes the parameter concerning the plurality of reader/writers a plurality of times; the control portion that sends the plurality of divided commands to the plurality of reader/writers successively based on the parameter and that receives an execution result of each of the plurality of divided commands from each of the plurality of reader/writers, a result storage portion that stores execution results of the plurality of divided commands that the control portion sends to the plurality of reader/writers based on each of a plurality of parameters that are changed by the parameter change portion, the execution results respectively being associated with the parameters on which the divided commands are based; and a calculation portion that calculates an appropriate parameter for the plurality of reader/writers based on the parameters and the execution results of the divided commands stored in the result storage portion.