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. Share on FacebookShare on TwitterShare on Google+ Comments are closed.