industrial//industrial automation//process automation

Process automation is the branch of industrial automation that controls processes whose variables change continuously, as in oil and gas, chemicals, power and water treatment. Pressure, temperature, level and flow are regulated rather than sequenced.

Process automation is the branch of industrial automation that controls processes whose variables change continuously, as in oil and gas, chemicals, power and water treatment. Pressure, temperature, level and flow are regulated rather than sequenced.

The task is to hold many interacting variables at their setpoints at once (pressure at 5 bar, level at 65 %, temperature at 180 degrees, flow at 200 t/h), which means tens to thousands of control loops, mostly PID, managed as a whole. It is one feedback control loop multiplied by a thousand and coupled through the same fluid, where alarm management and the interaction between loops matter more than any single gain. This is the home ground of the DCS.

The field side is instrumentation rather than switches: transmitters on 4-20 mA and HART, valves as actuators, and long plant lifetimes that keep several generations of instruments alive together (instrumentation).

A geographically spread process (a pipeline, a water network) adds the remote layer: RTUs and a SCADA center instead of a wired plant network.