Bob Nelson and Todd Stauffer, Siemens Energy & Automation

PLCs and DCSs Converge

In the past it was fairly easy to determine whether a distributed control system (DCS) or a programmable logic controller (PLC) based system was right for your application, because their strengths and weaknesses were well understood. In recent years, however, this has become more difficult, thanks primarily to the advancement of the microprocessor, which has allowed the technologies to converge.