Yokogawa Electric Corporation

Hiromichi Ebashi

Takeshi Nakajima

Masayuki Murakami

Kuniharu Akabane

Kenji Habaguchi

Toyoaki Yokoi

Koji Demachi

Takeshi Hongo

Akinori Ishii

Sadatoshi Sogo

Takashi Mizumori

Hajima Akai

A communication control system is provided that performs communications satisfying a request for industrial applications and a request for open protocol communications at the same time. To this end, in the invention, a high-priority communication section performing critical communications to provide real time property and reliability, and a low-priority communication section performing communications based on an open standard protocol coexist in a same communication station.

Communication control system

A communication control system is provided that satisfies the needs of industrial applications in terms of real time properties, scalability and flexibility. For this purpose, the invention causes a communication station performing communications in accordance with a standard protocol to perform multiplex communications based on time division of a communication band. Communication is performed by dividing a communication cycle into time slots, and assigning a set of communication stations and a type of a communication section to each of the time slots.

A duplex communication control device for a communication system comprising a plurality of stations which communicate data therebetween, wherein the stations are connected to a duplexed communication network and each station comprises a bus status list storing information indicating whether the station can communicate over a first or second communication line of the network; a token generating means which carries the newest bus status information on a token frame and transmits the token frame over the communication lines; a list updating means which receives the token frame transmitted over the lines and updates the contents of its own bus status list according to the bus status information carried on the token frame; and a transmission-reception means which selects one or both of the lines according to the bus status list for communication.

Duplex communication control device

Growing community of inventors

Tokyo, Japan

Hiromichi Ebashi