Patent ID: 8213443

Claim:
A network system comprising: a plurality of control systems; a network interface card mounted in each of the plurality of control systems, wherein the network interface card comprises: at least two communication ports, wherein each of the at least two communication ports selects a coaxial cable communication port for connecting a coaxial cable, a twisted pair cable communication port for connecting a twisted pair cable, or an optical fiber communication port for connecting an optical fiber cable for a data connection, such that each of the at least two communication ports is configured to utilize a different type of data connection or a same type of data connection; a controller interface unit configured to interface data with one of the plurality of control systems; a media interface unit connected with each of the at least two communication ports and configured to interface the data with other terminals; a first address designating unit interposed between a signal converter and the controller interface; the signal converter configured to convert data input from the first address designating unit to the media interface unit by converting binary data into an analog frequency signal according to a signal characteristic of the data connection; a first data repeater configured to transmit a data packet received from the first address designating unit to a second address designating unit of one of the plurality of control systems, wherein the first address designating unit is configured to: compare a physical address of the data packet with a physical address previously provided to the control system, transmit the data packet through the controller interface unit to the one of the plurality of control systems when the physical addresses are the same, and transmit the data packet through the controller interface unit to the first data repeater when the physical addresses are different; and a transmission media configured to connect each of the at least two communication ports with at least two other communication ports of one of the plurality of control systems in sequence so that the plurality of control systems has a phase structure of a ring topology.