RS-485: The Ever-Evolving Interface

Abstract: In a world obsessed with seeking new and “disruptive”technologies, the usefulness of some legacy technologies caneasily be forgotten. Over twenty years, since it was firstapproved by the EIA/TIA, the RS-485 standard continues to bethe workhorse of industrial automation communicationssystems.In this design solution, we review the requirements forusing RS-485 transceivers in an industrial environment (Figure1) and learn how these circuits have evolved. Finally, we considera new approach that will inject new life into this timelessinterface which shows no sign of retiring anytime soon.