A data processing system includes a unit which executes predetermined data processing by linking first and second apparatuses, a communication control unit which establishes and maintains a communication connection between the apparatuses even if the connection is not in a predetermined operation state capable of executing data processing, a pairing unit which causes the apparatuses to transition to a pairing state, and a control unit which, if the apparatuses' transition to the pairing state is not in a predetermined operation state, causes transition to the operation state by transmitting predetermined signals between the apparatuses via the communication control unit. The execution unit causes the apparatuses to transition to a pairing state, and then executes data processing by linking them. The communication control unit judges whether to establish a communication connection between the apparatuses by referencing pairing states between them, and of a combination with another first or second apparatus.