The leading news at the PI press conference covered the continuing growth of PROFIBUS and our first node count of PROFINET devices. (You can read the full press release here.) I tend to get all excited about PROFINET at the expense of PROFIBUS, so before I get to the PROFINET story, here’s the scoop about PROFIBUS. In calendar 2007, we sold 4,500,000 devices – a 25% increase over the year before. This brings our total installed base through ’07 to 23,300,000. To put this in perspective: we probably sold more PROFIBUS last year, than any other fieldbus in its lifetime (except for Interbus). [And, no we don’t count HART because it’s not a bus. But just so you know – they claim 23,000,000 installed devices with only about 10% actually using the HART functionality; the rest just use 4-20 mA for the process variable.] For a little more perspective, we probably sold more PROFIBUS last year than all the Industrial Ethernets over their lifetimes… combined. Ouch.
How do we know how many PROFIBUS devices were sold? Almost every device has a chip. The chips are made in a handful of different chip foundries. We count the chips. We are therefore very confident in the accuracy of the number.
Although I get all excited about the numbers and the fact that we’re number one in market share by a long way, so what? What if I’m a user or prospective user of a fieldbus? Why does this matter to me? It shows that PROFIBUS is a really well-accepted technology; I can safely choose to use it, too. Knowing of this large volume of devices installed I can correctly surmise that there are lots of products, lots of installations, lots of tools, and lots of know-how available.
For all of us who predicted that Industrial Ethernet would usurp the traditional fieldbuses – I guess we were wrong about the timetable.
The number of PROFINET nodes through 2007 was (ta-da)… 1,140,000. This is a pretty impressive number considering we got a later start than the other Industrial Ethernets. But I think even more impressive is what we counted and how we counted them. It would be tempting to count the infrastructure components, like Ethernet switches. We resisted temptation. It would be tempting to make an estimate of the number of devices. We resisted this temptation, too.
We counted only controllers (PLCs), remote IO stations, HMIs, robots, proxies, drives, and sensors. Note that we did not count each IO module, just the IO station. Some Ethernet switches include PROFINET IO capability so you can make them part of your engineering system for diagnostic and alarm purposes. We did not count these switches either.
How did we count the nodes? This is a lot harder than counting PROFIBUS nodes because PROFINET uses just standard Ethernet – no chip is required. So we engaged an independent third party to count anonymously (the third party is called a “notary” in the press release). We told the notary which companies to contact. The notary contacted them and requested their PROFINET node count. The companies returned their count directly to the notary. The notary then gave us the total. We never saw the individual companies’ numbers, just the total: 1,140,000.
One of the questions at the press conference was: “How do the other Industrial Ethernets count their nodes and what do they count?”
“You’ll have to ask them.”