Yokogawa Electric Corporation

Toyoaki Yokoi

Shunsuke Hayashi

Hideo Matsukawa

Takeshi Nakajima

Masayuki Murakami

Kuniharu Akabane

Kenji Habaguchi

Koji Demachi

Takeshi Hongo

Hiromichi Ebashi

Hiroshi Owada

Akinori Ishii

Sadatoshi Sogo

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 communication control system and method comprising, in one embodiment, a plurality of strobe signals are generated at different timings in a transmission circuit and a plurality of latch circuits equal to the number of strobe signals are provided in a receiver circuit so that data is retained in each latch circuit using the strobe signals one at a time.

Communication system and communication control method

A communication control system and method comprising, in one embodiment, a master station connected to a slave station using two redundant buses, wherein command frames having the same content are sent out to the buses and the communication process is changed depending on whether or not the contents of the command frames, when received by the receiving station, are identical.

A communication control system and method comprising, in one embodiment, a master station connected to a slave station using two redundant buses, wherein command frames having the same content are sent out to the buses and the communication process is changed depending on whether or not the contents of the command frames, when received by the a receiving station, are identical. In another embodiment, a plurality of units are connected to each bus in a multi-drop configuration, and a line length of each bus is defined so that reflected signals from other units reach a receiving unit on each bus after the transition period of a received signal at that receiving unit ends. In still another embodiment, a unit is connected to each bus and the unit is provided with a driver IC, wherein transmission data is first encoded into bit signals having a fixed number of bits, then the signals are supplied to the driver IC. In a further embodiment, a plurality of strobe signals are generated at different timings in a transmission circuit and a plurality of latch circuits equal to the number of strobe signals are provided in a receiver circuit so that data is retained in each latch circuit using the strobe signals one at a time. In a still further embodiment, an arbitration procedure is carried out using an arbitration bus when a bus master desires to use a data bus immediately after using the data bus, wherein it is determined whether arbitration has been carried out using the arbitration bus, and if none has been carried out, the arbitration procedure is omitted and the bus master is allowed to aquire the right to again use the data bus.

A Coriolis type mass flowmeter utilizing a measuring tube through which flows the fluid being examined and a pair of Coriolis signals generated thereby, wherein are provided a first and second A/D converter to convert the respective pair of Coriolis signals into respective digital signals; a first and second phase shifter for converting the respective digital signals to output signals each deviated from the respective digital signals by 90.degree.; a timing clock generator for supplying the first and second A/D converter with timing signals which are independent of vibrations of the Coriolis signals, and trigonometric calculating device for obtaining tan .PHI. using the following equation: tan .PHI.=(bc-ad)/(ac+bd), wherein a and c represent the outputs from the A/D converters, and b and d represent the outputs from the phase shifters, and tan .PHI. represents the tangent signal of the phase difference between the pair of Coriolis signals, whereby the speed of calculation is considerably increased and error of calculation is substantially eliminated.

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Tokyo, Japan

Toyoaki Yokoi