Rumble in the Fieldbus Jungle

I read with some bemusement the cries of protest railing against my "Fieldbus Jungle" articles (Industrial Networking,  Q1 and Q2, 2011, www.controldesign.com/articles/2011/FieldbusJungleIN11Q1.html and www.controldesign.com/articles/2011/FieldbusJungleIN11Q2.html). 

When I penned those articles, I knew that I could expect strong push back from individuals whose livelihoods are intertwined with the technology (Fieldbus instructors, salesman, etc.). What I did not expect was the large number of emails sent to me, thanking me for being one of the few people who wrote a balanced article about bus technology. That was very encouraging.

While I was willing to ignore the complaints the first time around, Mr. John Rezabek (a.k.a. "Chairman, Fieldbus Foundation End-User Advisory Council") felt obligated to repeatedly call me out by name for having the audacity to suggest that his beloved Foundation fieldbus was not the bastion of perfection his columns claimed it to be. In response, let me state a few simple facts:

1. I do not sell transmitters (fieldbus or 4-20 mA) and the fact is that I like digital fieldbuses, in the right application. I am not a technophobe, but I am an experienced implementer, who has worked in chemical plants for 25 years as both an end user and a systems integrator. I have designed, installed and supported fieldbus projects of various flavors, and the information in the articles was a direct result of my experiences and the experiences of others that I interviewed. Others may have different experiences (both better and worse), so there will always be arguments about whether a particular statement is too positive or negative.
   
   The article wasn't written to glorify nor vilify any technology, only to point out strengths and weaknesses, so the plant engineer could make an informed decision for his/her particular situation. The strengths are real, the weaknesses are real, and the intent of the article was to encourage readers to investigate beyond the hype.
2. Mr. Rezabek's columns are not nearly so balanced. This weekend I downloaded and read the last two years of his "On the Bus" column. In 24 issues, he never mentioned a single negative aspect of Foundation fieldbus, except to describe how misguided engineers might be for thinking such thoughts. How is that possible? Is it more responsible to write 24 articles espousing the benefits of a technology, rather than write one article suggesting there might be pros and cons? 
3. Interestingly, Mr. Rezabek did rail against other competing technologies (wireless, etc), branding supporters as "zealots" and complaining about their slanted savings calculators and failure to point out any of the negative aspects of the technology. Mr. Pot meet Mr. Kettle.

I realize this is heresy, but the fact is that no technology is going to take over the process industry and utterly replace the installed base because the simple truth is that every technology is well-suited for some installations and poorly suited for others. The words of anyone suggesting otherwise should be regarded very carefully.

P. Hunter Vegas
Avid Solutions, Inc.

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