Discrepancies upset me, so I was pleased to meet with John Morse of IMS at Hanover so I could ask him about the differences between the PROFIBUS node count he reported for 2006 and our own count. His was half of ours. I received a reply from John after he had the opportunity to review his data source. Turns out he had extrapolated based on previous data we had provided:
“15.4M Profibus notes were installed at the end of 2005 and that by 2010 that number would increase to around 20M by adding about 1M new nodes per year. At the time I felt this was underestimated and eventually settled on 1865.8K for 2006. In the event it would seem that this increased figure has fallen a lot short of reality.”
We are confident in the numbers we report. Why are we so sure of our numbers? We count the chips. Almost all PROFIBUS devices use an Application-Specific Integrated Circuit (ASIC) to unload communication tasks from the main device CPU. These chips are available from a number of suppliers who provide us with an accounting of their numbers. We don’t count the devices that don’t use the ASICs so we are probably under-counting the node count by a little.
John concluded his response: “These [reports] are always a snapshot in time but I would suggest that the rise in the sales of Profibus enabled ‘nodes’ has far exceeded all expectations.”