PURPOSE: To improve the line use efficiency by transferring data, which has a relatively small data volume but requires a quick responsiveness, with one polling and transferring data, which has a relatively large data volume but does not require a quick responsiveness, with plural pollings.

CONSTITUTION: When receiving a polling from a host computer 1, a terminal equipment A3 sends a text in a transmission buffer 8 to the computer 1 through a transmitting/receiving circuit 4. In this case, a quick responsiveness is required, and the whole of the text is transmitted with one polling. When the computer 1 sends a polling to a terminal equipment B11, the equipment B11 sends a text in a transmission buffer to the computer 1. In this case, a quick responsiveness is not required, and a transmission continuing flag is set, and the equipment B11 divides the text by, for example, two-block units to transmit it, and a data link is broken by a repeating code thereafter. Thus, the equipment A3 receives the polling from the computer 1 without waiting for a long time.