industrial//industrial automation//HMI

The **Human Machine Interface** is what the operator uses: process diagrams, buttons, alarms, trends, temperatures, motor states.

The Human Machine Interface is what the operator uses: process diagrams, buttons, alarms, trends, temperatures, motor states.

It can be a local screen on a machine, delivered by the OEM with the machine's own PLC, or a set of screens inside a SCADA or DCS.

What the operator can do through it is bounded on purpose: watch, acknowledge alarms, change authorized setpoints. Reprogramming the controller during a shift belongs to the engineering station, not to the HMI.

The HMI shows the present. History, contextualization and analysis are other layers (historian, MES).