The machinery itself is often mechanically sound, reliable, and doing the job for which it was built perfectly well. Yet, it is digitally silent. Older PLCs do not have spare input/output (I/O) capacity, and many lack Ethernet altogether. Some plants no longer have the original source code, and, even when they do, nobody wants to touch working logic. One incorrect edit, and you are explaining to the operations manager why a validated line just went down.
So, you're stuck. The data everyone wants is locked inside machines nobody dares modify, an impasse that has defined legacy plant modernisation for years.
IO-Link, combined with capable edge devices, is changing that. This quiet yet rapid evolution means it is now possible to extract meaningful intelligence from legacy equipment – without going anywhere near the original PLC code.
Read the full article in DPA's January 2026 issue