There’s an article from Automation World, “Ethernet-based Motion Hot and Real-time,” that briefly describes the various Ethernet-based motion control protocols – emphasis on the word briefly. For a more complete explanation of how PROFINET does motion control, download the PROFINET booklet. PROFINET is the one technology that does all the things that need doing in industrial automation, motion included.
According to the article, ODVA “didn’t do anything to bastardize the standard OSI (model’s seven) layers.” I marvel that they think that trying to force an office standard into the industrial space is a good thing. Sure, keep the standards that can be used, like Ethernet (the lower two layers), but the industrial space makes far different demands on the software (the upper 5 layers) than the office space. PROFINET elected to create an industrial standard instead. Even there we use the standard TCP/IP layers when it makes sense, like for configuration and diagnostic information.
One thing really struck me about this article: PROFINET was the only technology whose spokesperson was from the open organization that supports the technology – all the others were from a vendor. So when I talk about global support for the technology (as I did in my last post), I mean support from an open, independent, multi-vendor organization.