Patent ID: 6658495
Filing Date: 2003-12-02
Classification: H04L

Abstract:
A data communication apparatus for opening and transmitting data to at least one of a plurality of communication ports, comprising:transmitting means for providing an address region showing addresses corresponding to the plurality of the communication ports respectively in a command for opening the communication ports, wherein each said address has a corresponding data, and for transmitting the command to the plurality of the communication ports with the data of the address of at least one select communication port which is to be opened being set a first predetermined value; receiving means for receiving the command transmitted back from the plurality of the communication ports and determining whether the at least one select communication port is opened based on the data being set a second predetermined value in the address of the at least one select communication port in the address region of the command for opening the communication ports; wherein the select communication port becomes opened by the first predetermined value in the command transmitted from the transmitting means and data is transmitted to the select communication port opened.