SPS Drives 2008 Report: IO-Link Posted December 3rd, 2008 by Carl Henning & filed under Uncategorized. I’ve previously described IO-Link as HART for discrete. IO-Link was widely displayed at this year’s show. For more explanation, how it fits with PROFIBUS and PROFINET, reports, photos, and video, click here. ShareTweetPinStumble Comments are closed.