Yamatake Corporation

Fieldbus Foundation

Yasuo Kumeda

Hiroshi Mori

Mitsugu Tanaka

Ram Ramachandran

Lee Allen Neitzel

Thomas B Kinney

Kenneth D Krivoshein

David A Glanzer

Jack Elias

Chuji Akiyama

William R Hodson

Patricia E Brett

Frank Lynch

Ashok K Gupta

Terrence L Blevins

Masato Kuroda

Shinichi Akano

Fumio Nagasaka

Terrance L Blevins

A field apparatus for controlling a controlled element includes a diagnosis unit for diagnosing abnormality of the field apparatus and/or the controlled element and a bidirectional digital communication device to send a digital signal which shows a diagnosis result to outside and to receive a digital signal from outside in order to execute a control of the controlled element. Other predetermined functions are effected based on a command signal in the form of an analog signal received from outside by a analog communications device of the apparatus. Electric power for operation is supplied through a switching means that can switch either a electric power that is supplied by the analog communications device or a electric power that is supplied by the bidirectional digital communication device.

Field apparatus

The present invention is a block oriented control system that allows interoperability between devices made by different manufacturers. A block oriented control system is a system which includes a plurality of field devices incorporating a physical layer, communication stack, and user layer, with the field devices being connected by a transmission medium, such as a bus. The physical layer receives signals from the bus and translates the signals into a message for the communications stack, and receives messages from the communications stack and translates the messages into signals for the bus. The communication stack controls the communications between devices operating in the control system. The user layer is a block oriented approach to the system's control functions, and includes function blocks and system management. The function blocks are standardized encapsulations of control functions, such as analog input or proportional/derivative. The system management allows synchronization of the device applications and the network processing.

Block-oriented control system

When each access apparatus is to update its own data written in a common memory device, the transmitting unit of each access apparatus transmits the previous data previously written in the memory device and new data to be newly written in the memory device as a pair of data via a bus. Upon receiving the pair of data from the access apparatus, a determination unit in the common memory device determines whether the data stored in a memory coincides with the previous data received from the access apparatus. If these two data coincide with each other, the data in the memory is rewritten into the new data; otherwise, a data update in the memory is rejected.

Method and apparatus for controlling memory access by a plurality of devices

Block oriented control system

Growing community of inventors

Tokyo, Japan

Yasuo Kumeda