PURPOSE: To omit trouble of revision of an information generation frequency itself of an information generating section when the transmission frequency of the information of the information generating section is desired to be revised during transmission of the information in the information multiplex transmission in which information generated from plural information generating sections is sent to one information transmission section.

CONSTITUTION: A selection frequency table 9 is added to an information selection section 7 extracting information generated from plural information generating sections 1 and the information selection section 7 selects the information generated by the information generating section according to the frequency stipulated by the selection frequency table 9. Then the content of the selection frequency table 9 is revised by the information generating sections 1, 2, 3, the transmission frequency of the information by each information generating section during transmission of information is revised without changing the information generating frequency of the information generating sections.