Fieldbuses are down and Industrial Ethernets are up? Is that what a new IMS Research study shows (How Sustainable is an Industrial Fieldbus Infrastructure?)? Or, as Larry O’Brien put it in his blog post (What’s in a Node? Putting Market Research in Perspective): “[T]he study results have caused quite a stir in the media because they seem to predict the doom of fieldbuses in general in favor of Ethernet.” So, are fieldbuses doomed? NO! Despite the headlines, I think the real conclusion should be: “Fieldbus use is up, but Industrial Ethernets are growing faster, but from a smaller base.” It’s easier to have dramatic percentage growth if the base is small. Well, smaller than fieldbus anyway. By way of comparison, PROFIBUS installed nodes exceed 45 million and PROFINET, 6 million.
The study conflates discrete and process buses. It must be noted that there is no Industrial Ethernet equivalent for PROFIBUS PA or Foundation Fieldbus … today. You can’t have an Industrial Ethernet land in a hazardous area. Will the time come when that will change? Yes. For now though, the need for process buses will be filled by PROFIBUS PA and FF. In the factory world it’s different. There Industrial Ethernet is quickly becoming ubiquitous at the expense of serial fieldbuses.
A couple footnotes:
Larry wondered what a node was in IMS’ report. I had wondered the same thing from one of their earlier reports. I asked the question and got an answer that I reported at What is a Node?
If IMS is asserting that Industrial Ethernets are simpler to use than fieldbuses, I would agree. Finding installers for Ethernet is much easier than finding installers for fieldbuses. Ethernet is well-known and has no need for terminators or load calculations.
–Carl Henning