Patent ID: 7643167

Claim:
A data communication apparatus connected to a plurality of transmission sources, the apparatus comprising: a reception unit configured to receive data from the plurality of transmission sources; an input unit configured to input at least transmission source specification information for specifying one of the plurality of transmission sources which is supposed to transmit expected data and reception period-of time specification information for specifying a period of time during which the expected data should be received, as conditions for specifying the expected data from among data received by the reception unit; a determination unit configured to determine whether or not the reception unit has received the expected data satisfying the conditions input by the input unit; and a notification unit configured to automatically transmit a message indicating that the expected data has not been received to the transmission source which is supposed to transmit the expected data and specified by referring the transmission source specification information input by the input unit as the conditions, in a case where the determination unit determines that the reception unit has not received the expected data satisfying the conditions.