OTHER FIELDBUS STANDARDS
Foundation Fieldbus - The result of work by many of the leading companies in process instrumentation, closely linked to the emerging international standards. It provides for operation at 31.25 kbps over a variety of media configurations and a higher speed (1 Mbps) version for use where larger amounts of data are involved and the lower power requirements of the slower system are of less importance.
- PROFIBUS- A fieldbus originating primarily from Germany, with three variants: FMS and DP for high speed applications, and PA for process automation.
- EN50170 FIELDBUS - A European standard, incorporating FIP, Profibus and P-Net.
- FIP - A fieldbus originating primarily from France, offering a high-speed device level protocol and a lower speed process version.
- P-NET - The third member of the EN50170 fieldbus techniques. It operates over a variety of media using a master-slave protocol with the capability for multiple masters.
Some useful terms
MASTER-SLAVE- Communications technique where a single device has overall control of a network of devices.
PEER-TO-PEER- Communications technique with many devices on a network each having equal rights of access to all of the others, with no single device having priority or coordinating powers.
ANSI X3.28 1976 - The standard for master-slave communications used in many older Status Instruments products.
FIELDBUS- Strictly, a general term for a communication system between elements of a control or monitoring system where the parts of that system are distributed throughout the installation being controlled / monitored. Over recent years the term has become associated with the worldwide movement towards a single common standard for communication between items of process control equipment.
IEC 1158 - The developing international standard for fieldbus. IEC1158-2 defines the physical layer and has been adopted by a number of the fieldbus developers as the first stage in moving towards a unified worldwide standard.
ETHERNET- A local area network (LAN) architecture developed by Xerox Corporation, with DEC & Intel, in 1976. Ethernet uses a bus or star topology and supports data transfer rates of up to 100 Mbps. In the case of Switched Ethernet, the hub is replaced by a switching hub, thus bandwidth is increased.
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