PURPOSE: To decrease the number of times of retrieval by providing a pointer table based on an information in a text.

CONSTITUTION: A pointer table PT is provided, which constitutes a basic number connecting a part or all of address information extracted from a transmission side equipment address designated in a transmission/reception text and a part of all of number information extracted from the logic unit number of a receiver and uses the basic number as a pointer, and a bus control table is arranged according to the pointer. Thus, uniform distribution of bus control tables TP01∼TP62 is expected along with the pointer, the table pointer is used as the index for search, then useless search number of times is avoided and the processing time is reduced remarkably.