The user interface in a manufacturing or process control system. It provides a graphics-based visualization of an industrial control and monitoring system. Previously called an “MMI” (man-machine interface), an HMI typically resides on a computer that communicates with a specialized computer in the plant, such as a programmable automation controller (PAC), programmable logic controller (PLC) or remote terminal unit (RTU). The HMI generally comes in two forms: either a touch panel or a software-based application that is loaded on a personal computer, workstation, tablet, or smart phone.
Copyright: Cybersecurity & Infrastructure Security Agency