From automotive infotainment centers to tablet computers, smartphones and industrial machine controls, interfaces are everywhere. They are used for both leisure and commercial purposes, with some interfaces found in the home and others found in the workplace. The fundamental purpose of an interface — regardless of purpose — is to provide a means for controlling a device, computer or piece of equipment. All interfaces are designed for this very purpose, but the way in which they work varies depending on the specific type. A lesser-known type of interface that’s become increasingly popular in recent years, however, is a human machine interface (HMI).

What Is an HMI?

An HMI is a special type of interface that’s used specifically to control a machine. The term “human machine interface” is a catch-all term that covers all interfaces that allow a user to control a single machine — the keyword being a single machine. It’s not uncommon for companies to use traditional graphical interfaces so that workers can control multiple machines or equipment in their workplace. An HMI allows this same level of control but for a single machine or piece of equipment rather than multiple machines or pieces of equipment.

Components of an HMI

Like all interfaces, HMIs consist of a variety of components. While the exact type of components and their respective quantities varies depending on the specific HMI, most include a few basic components. A typical HMI may feature membrane switches, rubber keypads and even a touchscreen displays. Membrane switches are electrical switches made of a soft, membrane material that deforms when pressed and reverts back to its original size and shape thereafter. Rubber keypads, as you may know, are keypads designed with a rubber-silicone construction. And touchscreen interfaces are displays that allow the user to control the connected device or machine by touching icons and other digital elements on the display. When used together, these components create a highly functional HMI that can be used in a variety of industries.

Other Types of Interfaces

Of course, HMIs are just one type of interfaces. There are also graphical user interfaces, web-based interfaces, text-based interfaces, conversational interfaces and more. The defining characteristic of an HMI, however, is that it controls a single machine or piece of equipment rather than multiple. After reading this, you should have a better understanding of HMIs and how they work. For many companies, it’s an essential tool used in their daily operations.