Patent ID: 7463586

Claim:
A data transfer apparatus that receives from an upper station a data stream that includes a plurality of types of repeat data, each type of repeat data being repeatedly transmitted according to a carousel transmission method by the upper station and repeat data of a same type being identical in content, and transfers the repeat data to a lower station, comprising: storage means having a storage area; extraction means for extracting the types of repeat data from the received data stream; writing means for writing the extracted repeat data to the storage area; data structure ratio determination means for determining a ratio between the types of repeat data to be output in a data stream per fixed length of time; and data output means for outputting the repeat data at the determined ratio by reading and outputting each type of repeat data a number of times that corresponds to the determined ratio, wherein each of the plurality of types of repeat data is composed of a plurality of data packets, each of a same size, the data structure ratio determination means includes: a counting unit for counting, for each type of repeat data, the number of data packets extracted over a predetermined length of time, and the data structure ratio determination means determines a ratio between the number of data packets counted for each type of repeat data as the ratio between the types of repeat data to be output over a fixed length of time.