Digital Busses

As reported in the Sound OFF! Editors' Blog, the ISA issued a press release announced that the ISA-SP104 committee has completed adoption of EDDL as an ANSI standard specified by IEC 61804. It is now: ANSI/ISA-61804-3 (1004.00.01)-2007, Function Blocks (FB) for Process Control - Part 3: Electronic Device Description Language (EDDL).

So if you are an automation engineer you might ask... so what? I have attempted to address this "so what?" question in prior posts, but it is something I will try again in my quest to simplify in my mind--if not yours.

The best way I can think of it is a text-based file that is associated with your smart Foundation fieldbus, HART, or some of your PROFIBUS devices in your plant. This text-based file presents its operation, diagnostic, performance analysis, operating statistics, calibration and other information in a standard, globally agreed upon way. Applications like your control system, asset management software and handheld devices that support this standard can present the information to you in a standard, intuitive way.

The analogy I have used in the past is the Really Simple Syndication (RSS) standard for publishing and consuming information across the web. Like the smart field devices, web news feeds, blogs, and other RSS-enabled content provide their information in this agreed upon global data standard. You can use RSS readers like my favorite, Google Reader, to read the information to which you choose to subscribe.

Continuing the analogy, your RSS reader presents this information to you in a common way--the look, the fonts, the shortcut keys, etc. The content can come from different suppliers' web servers, be on different operating systems, and even run with different software applications that create these standards-based RSS files.

Likewise, your application that understands the global EDDL standard (like Emerson's AMS Device Manager and 375 Field Communicator) can present the information from various smart field devices, from different suppliers, and even running different digital communications protocols. As ISA-SP104 Committee Chair (and fellow blogger), Terry Blevins said in the release:

Using tools based on EDDL can mean faster device commissioning and loop checkout, as well as reduced field trips and the elimination of unnecessary maintenance.

In an earlier post, I had mentioned the ISA-SP104 committee had established an EDDL.ORG site as an educational site. The committee has been hard at work creating educational information including basic information, participating organizations in this standard, and other news, events, and technical resources.

And, as reported this past April, the EDDL team and another smart device-based standard, FDT Group, agreed to combine efforts and work toward a unified solution for device integration that is compatible with both technologies. ARC Advisory Group sums up this collaborative effort well:

ARC applauds the collaboration efforts of the parties involved. The actions of this group will be remembered as the tipping point where practical common standards for field device integration were founded. Working toward the singular goal of easy equipment configuration and management will provide more value than anyone could have imagined.

For those like me who were college educated in the pre-internet, pre-Google days you can really appreciate how access to information required for learning has gotten easier. With a Google search bar and some quiet time, you can become conversational on nearly any topic in a few minutes and on the road to being an expert with some more time. There is no way we could learn this quickly in the days of libraries and books.

I bring this up because Terry Blevins, co-author of the Modeling and Control blog, and Emerson's Marcos Peluso have made their "best of" Foundation Fieldbus tutorial presentations available over on the EasyDeltaV.com website. This tutorial is covered in 12 parts from a very basic Fieldbus Overview to Advanced Functionality. The presentation series includes:

• Fieldbus Overview
• Justifying Fieldbus
• Example Applications
• Installation of Fieldbus
• Devices Available
• Fieldbus Standard
• Fieldbus Communication
• Fieldbus Function Blocks
• Fieldbus Diagnostics
• Fieldbus EDDL
• HSE Fieldbus
• Advanced Fieldbus

As technologists, Terry and Marcos have created a presentation series which more deeply explores the workings of Foundation fieldbus. This series complements the modules in PlantWeb University in the Foundation fieldbus section in the way an advanced class complements the introductory class.

If you happen to be searching around for information on Foundation Fieldbus and happen upon this blog post, enjoy the fact how quickly you can get conversational or become a true expert based on the time you spend following some of the links.

It's always a pleasure to highlight the work of our technologists around Emerson Process Management. It's even better when their work is recognized by ISA, a premier organization for automation professionals. Congratulations to Martin Zielinski and Carl R. Jones on their recent awards for outstanding achievement.

Martin, the Director of HART and Fieldbus technology in Emerson's Asset Optimization division, was elected to the distinguished grade of ISA Fellow for his significant contributions in the development, standardization, and deployment of digital communications technology. Through his career he has worked in the forefront of some of the automation world's leading open, interoperable communications standards including the HART Field Communications Protocol, the FOUNDATION fieldbus communications standard, and the Electronic Device Description Language (EDDL). In fact, for two years while the Fieldbus Foundation was getting started, Martin served as its Chief Operating Officer. If your automation system or asset management software is receiving diagnostic information from intelligent field devices, you can bet that Martin's leadership and expertise went into it somewhere along the line from his work on these consortia and standards bodies.

Carl, retired from and now consulting with Emerson's Rosemount Analytical division, received the UOP Technology Award for the development of process analyzer applications, particularly those used in spectrophotometry. This award recognizes an outstanding achievement in the conception, design, or implementation of instrumentation and/or process control in an area of activity covered by the scope of the ISA's Automation & Technology Department. Carl developed numerous process analyzer applications, using a full range of liquid and gas process analyzers and holds a patent for a unique electrochemical oxygen sensor and technology that speeds response time. He has contributed numerous publications and presentations serving to advance process instrumentation technologies.

We're honored to have Martin and Carl recognized for their contributions to the advancement of automation technologies which help make process manufacturers more efficient.

In April 1997, the first commercial Foundation fieldbus application was installed in a Canadian plant running a series of ethylene furnaces. Emerson technology experts including a process automation hall of fame member were on the scene in this new chapter in process automation.

Since that time, process manufacturers around the globe and across many industries have been realizing benefits in installation and ongoing operations from this digital communications technology.

The ARC Advisory Group is performing a survey on Operational, Maintenance, and Engineering Benefits Related to Foundation Fieldbus. They are particularly interested in responses from end users that have implemented Foundation Fieldbus in their plants.

If you'd like to participate, here's the link to the ARC survey. I hear that the survey is open through the first week of August, so hopefully you can squeeze in a few minutes to answer the 15 questions. As a participant you'll receive a free copy of the results.

I'm curious what the ARC findings will be, and will be sure to point you to any highlights the ARC folks freely share.

The news of Emerson and Siemens working together to "exchange technology that will extend interoperability and end-user benefits" hit the business wire earlier this week.

The reaction among the small but growing band of bloggers in the process automation space soon followed.

AutomationWorld magazine's editor-in-chief Gary Mintchell wrote in his Interoperability Propelled post:

In both cases, this means more ability for customers of each to integrate more systems. Definitely a win for the customers. Competitors of each of these companies have long grumbled about them being pretty much closed companies when it comes to working with others. I guess this pretty well shatters some of that thought. Good to see them opening up.

Carl Henning over at the PTO PROFIblog wrote in his Wow! Talk about giving users a choice... post:

Emerson is known for supporting Foundation Fieldbus (FF) and Siemens will add support for FF to its devices.

Siemens is known for supporting PROFIBUS and PROFINET and Emerson will support those standards in its offerings.

I'd like to make a quick point that Emerson has a longstanding commitment to interoperability. The DeltaV system and many other Emerson products have supported HART, Foundation Fieldbus, OPC, Profibus DP, DeviceNet, AS-i bus, ODBC, XML, web services, and more recently wireless and many other important interoperability standards. A quick look at this fieldbus interoperability video circa 2001 demonstrates this longstanding commitment to interoperability. Also a quick Google search on Interoperability on the EmersonProcess.com site yields quite a few results.

I caught up with Duncan Schleiss, the marketing VP for Emerson's Process Systems and Solutions business which manages the DeltaV system about this latest announcement. His view is that standards are very important as it gives process manufacturers freedom of choice. The standards must facilitate innovation allowing each supplier to provide increased value to customers. With the innovation flexibility in the standard, the process manufacturer is the clear winner in being able to choose between suppliers yet at the same time being able to select products that have clear differences. It is this innovation that drives technology that improves process manufacturing productivity and adds the most value. So while standards are good, they must endorse and allow innovation.

A final point on difficulty in achieving interoperability from a very good AutomationWorld magazine article by Jim Pinto, entitled The Dichotomy of Open Standards:

End-users continue to ask for interoperability as a means to achieve vendor independence. But that is the exact opposite of what all the primary suppliers want. Standards turn proprietary products into commodities, with lower profit margins.

As Duncan points out, if the standard provides the flexibility to innovate to create value, it is something everyone-- both suppliers and end users alike can support.

As more and more process manufacturers incorporate digital busses into their automation architectures, debates often occur whether to limit the plant to a single bus or to incorporate multiple busses.

You can see both sides of this argument on a Foundation fieldbus forum in a Mixing fieldbuses thread. The original question posed:

In a new plant scenario, lets say an 800 point I/O count with about a 50-50 mix of analog and discretes. I think it's a no-brainer to go FF [Foundation fieldbus] where applicable for the analog control/monitoring. The question is, the remaining 400 or so points where we need shut-off valves, motor controls etc. what do we do?

Multiple buses should not be mixed in a system, not because it can't be done, because it can be done using most control systems in the market today, but because the system gets messy and expensive to operate and maintain.

Emerson's position in this debate differed greatly and was well articulated by Dewey Kuchle in our Hydrocarbon and Energy Industry Center in Calgary.

His key points in this forum thread include:
1. Remember the objective is to have projects on budget, on schedule, and operate efficiently. The selected technology is a means to this end.
2. No one digital bus technology is best for all the types of transmitters, actuators, motors, analyzers and other process instrumentation. Each technology and how it is implemented in the various process automation systems has its strengths and weaknesses. Pick the right one for the job.
3. Nothing beats "hands on" to compare the various systems and how they implement these digital busses like Foundation Fieldbus, Profibus DP, DeviceNet, and AS-bus. This is a great way to see what it takes to engineer, install, commission, operate and maintain them.

Digital busses like Foundation fieldbus are great for much of the process measurement and actuator instrumentation. It can be used, but is not as good a fit for motor control centers as DeviceNet or Profibus DP. The ideal situation is to have a single architecture that can support all of the most common busses and integrates them seamlessly, like our DeltaV system.

Conversely, these more discrete-oriented busses cannot pass back to the engineers, operators, and maintenance personnel the predictive diagnostics that intelligent measurement and actuator instrumentation contain that help run the process more efficiently and with fewer upsets.

Most of the reasons for the differences are the analog or discrete starting points of the technologies. Without delving into longer explanations, I will point to PlantWeb University's Engineering School which goes into the choices and tradeoffs in the "Choosing the right bus" section.