Profibus vs. FOUNDATION fieldbus; ControlNet vs. Interbus; DeviceNet vs. SDS; Seriplex vs. AS-Interface—the bus wars continue to rage. But a new challenger has changed the battle.Ethernet, a standard in business networking since the mid-1980s, is touted by vendors and users alike as a contender for industrial applications.
In a stunning though not unexpected rebuke, the International Electrotechnical Commission's national committees voted Sept. 30 not to publish IEC 61158 as an international fieldbus standard. National members narrowly rejected Final Draft International Standard (FDIS) documents covering IEC 61158's Data Link Layer (DLL) and the Application Layer (AL).
In the second question of the Q&A sidebar that accompanied the "Implementing Industrial Networks" article in Control Engineering , July 1998, p. 114, misspelled the acronym for the most common cabling scheme, DB9. In Control Engineering , July 1988, p. 133, an incorrect location was given for Emcor Products.
No man is an island and pretty soon many factory networks will be a lot less isolated too.To help transform these networks from proprietary islands of automation into globally manageable data and control systems, Osicom Technologies Inc. (Santa Monica, Calif.) unveiled an alliance June 22 of four automation firms it says are committed to Internet- and Ethernet-based control networks.
Phoenix Contact discussed its "75 Years of Innovation" with more than 60 media representatives from around the world at its global headquarters here on June 17-18. Highlights included tours of two plants, presentations on intelligent networking, innovations in connection and interface technologies, and discussions of the Interbus digital industrial network.
More than 350 industry professionals attended the first "pc & automation" conference here on March 26-27. Organizers presented the international standards for Microsoft Windows running on PCs with fieldbus networks as the technologies that will drive automation in the future.
Working overtime at their 1998 General Assembly, Fieldbus Foundation (FF) members took action March 5 on an array of milestone issues. Most of these related to controls and instrumentation end-users preparing to install FOUNDATION Fieldbus systems, according to John Pittman, president of the Fieldbus Foundation (Austin, Tex.
When I joined Control Engineering 11 years ago, one of our seasoned editors said to me, "Jane, keep an eye on that ISA SP50 committee. They're trying to develop a digital networking standard for smart communication among multiple vendors' instrumentation. It's going to be the biggest thing since 4-20 mA!"We waited.
I thought the article, "Selecting the Right Industrial Network," [Control Engineering, January 1998, p. 61] was both interesting and useful. We are in the process of swimming through the variety of selections that are out there. This article was helpful! Thank you!Rick Tyson, electrical engineer, Salt Lake County Water Conservancy District, West Jordan, Ut.
As controls and automation become more distributed and integrated, industrial communication networks and buses are becoming more crucial because they link controls with real world, in-the-trench, manufacturing processes. However, due to growing choices of networks, protocols, buses, and node connections, it is helpful to understand the basic aspects of each network or bus before picking an overall architecture. Physical topologies include linear buses (with drops), and daisy-chained, ring (where all nodes are connected in a physical ring), star, and mixed types. Each has its own advantages and drawbacks. Bus arbitration schemes include master-slave and peer-to-peer (CSMA or collision sense/multi-access, and token-passing).