A data processing apparatus executes a process on each piece of data repetitively transmitted from a device and transmits processing information on the process to a receiving apparatus, and includes an outputter and a GW communicator. The outputter acquires conditional information, indicating whether a transmission condition required for transmission of generation data generated in execution of the process to the receiving apparatus is satisfied, after every generation of generation data. When the conditional information indicates satisfaction of the transmission condition for the piece of generation data, the outputter outputs additional information on satisfaction or dissatisfaction of the transmission condition for at least one of another piece of generation data generated immediately before or after the piece of generation data. The GW communicator transmits the processing information including the generation data for which the condition is satisfied and the additional information to the receiving apparatus.