"High Speed Ethernet-Promoting Openness in Hybrid Control" debunks the myth that developments in Ethernet backbones are directed only towards high speed, real-time factory automation. This paper shows how high speed Ethernet supports hybrid control through standard and flexible function blocks, bridging Fieldbus networks and allowing the use of Foundation Fieldbus and Profibus solutions.
Reviewed paper
High Speed Ethernet
Promoting openness in hybrid control
Eugenio F. da Silva Neto and Peter G. Berrie, Endress+Hauser Process Solutions AG
Many tasks in Process Automation require a combination of continuous and sequential control. Develop-ments in Ethernet-based backbones, however, are increasingly addressing the problems of high-speed, real-time Factory Automation only. There is one exception: FOUNDATION Fieldbus High Speed Ethernet. This paper shows, on the basis of practical examples, how High Speed Ethernet supports hybrid control through standard and flexible function blocks, provides innovative and powerful solutions by bridging field-bus networks, and allows the use of both FOUNDATION Fieldbus and PROFIBUS solutions when the applica-tion demands it.
Flexible Function Block / FOUNDATION Fieldbus / High Speed Ethernet / Hybrid control / PROFIBUS
1. Introduction as complementary technology and show how HSE can be used for hybrid control on the basis of practical examples. In It is a common misunderstanding that the High Speed Ether- addition, the benefits, acceptance and prospects for the net specification, first published in 2002, is a communication future will be briefly discussed.standard only, i.e. a way of getting control-relevant data from A to B. Nothing could be farther from the truth. It is the result of many years deliberation on the functions required 2. High Speed Ethernetat the supervisory/control level to supplement the powerful concept of the Function Block Application Process embed- HSE as plant backbone provides more than just a physical ded in the Fieldbus Foundation H1 specification. High Speed path and control of media access. It is fully standardized up Ethernet, as an open standard, contains a user layer that to and beyond the application layer. This paper does not provides everything required for decentralized process con- describe HSE in detail, but restricts itself to a general over-trol. It is "Internet for Process Automation". view of the features of interest to its use. More detailed infor-As Internet users we just plug-in, call up our favourite mation is to be found in the specifications and any good browser and look for the information we require. We use book on the subject [1, 2, 3].search engines to find information, send and receive e-mails, upload and download files, participate in interactive chat 2.1 Physical layersessions, pay bills, subscribe to publications, add short-cuts to "favourite" sites, etc. As a site owner we might also register Table 1 summarizes the main properties of the High Speed the number of clicks, check the origin of visitors, keep statis- Ethernet physical layer. Since they are Ethernet based, net-tics and monitor trends. If we attempt to access a closed site, works use a variety of commercial off-the-shelf (COTS) hard-an error message is displayed, but should it move from one server to another, more often than not, we are automatically Table 1: Physical specification of High Speed Ethernet.rerouted. In fact, how we get from A to B does not concern Property Descriptionus at all. We just enjoy the benefits of having open, i.e. stan- Standard IEC 61158; Application Layerdardized and seamlessly integrated web applications. Support Fieldbus Foundation OrganizationIf we look closely at the activities in a decentralized cont- Physical layer IEEE 802.3u; Ethernet 100BaseT, 100BaseFrol system, we see remarkable analogies to those performed Cable: Copper: 2x shielded twisted pairs; in Internet: data exchange, data acquisition, visualization, Optics: fibre optic cabletrending, alarming, parametrization, asset management, Cable specifi- Supported twisted pair cable category 5 or fibre optic cation componentsperformance tuning and security management. How would Max. length (UTP/STP)100m or (Multimode Fibre) 2000m, possible it be if we could just plug-in our host and see the whole plant to expand with repeaters (switches)view and have access to every asset? Participants 256Would this be an advantage? Does a "broad interoperabi- Transmission 100 Mbps (fixed)lity concept" bring any tangible savings and benefits to the rateplant? In this paper the authors will examine HSE more clo- Bus access CSMA/CD: Carrier Sense Multiple Access/ Collision De-sely, discuss the concept of the ... [download for more]
