COMMUNICATION CONTROL DEVICE

A communication control device (1a) is provided with: a communication request processing unit (11) that, on the basis of write-in request information, creates a command frame that writes data to a transmission destination, and transmits the command frame to a PLC communication processing unit (10-1 to 10-n) that corresponds to an available connection; a communication request processing unit (13) that generates a command frame for reading data from the transmission source on the basis of read-out request information, and transmits the command frame to regulator communication processing units (12-1 to 12-m) corresponding to the transmission source; and a data transmission processing unit (14) that creates read-out request information for a transmission source defined in the data transmissiondefinition information of a data transmission definition unit (15), and, when data requested in the read-out request information is received from the transmission source, creates write-in request information for writing the