What is Human Machine Interface?

A Human Machine Interface (HMI) is a user interface or dashboard that connects a person to a machine, system, or device. While the term can technically be applied to any screen that allows a user to interact with a device, Human Machine Interface is most commonly used in the context of an industrial process.

According to the NIST of the US:

The hardware or software through which an operator interacts with a controller. An HMI can range from a physical control panel with buttons and indicator lights to an industrial PC with a color graphics display running dedicated HMI software.

Human Machine Interfaces are similar in some ways to Graphical User Interfaces (GUI) but they are not synonymous; GUIs are often leveraged within Human Machine Interfaces for visualization capabilities.

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In industrial settings, Human Machine Interfaces can be used to:

Visually display data
Track production time, trends, and tags
Oversee KPIs
Monitor machine inputs and outputs
And more

Similar to how you would interact with your air-conditioning system to check and control the temperature in your house, a plant-floor operator might use a Human Machine Interface to check and control the temperature of an industrial water tank, or to see if a certain pump in the facility is currently running.

Basic Human Machine Interface examples include built-in screens on machines, computer monitors, and tablets, but regardless of their format or which term you use to refer to them, their purpose is to provide insight into mechanical performance and progress.

Who Uses Human Machine Interface?

HUMAN MACHINE INTERFACE technology is used by almost all industrial organizations, as well as a wide range of other companies, to interact with their machines and optimize their industrial processes.

Industries using Human Machine interfaces include:

Energy
Food and beverage
Manufacturing
Oil and gas
Power
Recycling
Transportation
Water and wastewater
And many more

The most common roles that interact with Human Machine Interfaces are operators, system integrators, and engineers, particularly control system engineers. Human Machine Interfaces are essential resources for these professionals, who use them to review and monitor processes, diagnose problems, and visualize data.

Common Uses of Human Machine Interface

Human Machine Interfaces communicate with Programmable Logic Controllers (PLCs) and input/output sensors to get and display information for users to view. Human Machine Interface screens can be used for a single function, like monitoring and tracking, or for performing more sophisticated operations, like switching machines off or increasing production speed, depending on how they are implemented.

Human Machine Interfaces are used to optimize an industrial process by digitizing and centralizing data for a viewer. By leveraging the Human Machine Interface, operators can see important information displayed in graphs, charts, or digital dashboards, view and manage alarms, and connect with SCADA and MES systems, all through one console.

Previously, operators would need to walk the floor constantly to review mechanical progress and record it on a piece of paper or a whiteboard. By allowing PLCs to communicate real-time information straight to a Human Machine Interface display, Human Machine Interface technology eliminates the need for this outdated practice and thereby reduces many costly problems caused by a lack of information or human error.

What is the Difference Between Human Machine Interface and SCADA?

Supervisory Control and Data Acquisition (SCADA) and Human Machine Interface are closely related, and often referred to in the same context since they are both parts of a larger industrial control system, but they each offer different functionality and opportunities. While Human Machine Interfaces are focused on visually conveying information to help the user supervise an industrial process, SCADA systems have a greater capacity for data collection and control-system operation. Unlike SCADA systems, Human Machine Interfaces do not collect and record information or connect to databases. Rather, Human Machine Interface provides an effective communication tool that functions as part of, or alongside, a SCADA system.

Developing Trends in Human Machine Interface Technology

In the past decade, changing operational and business needs have instigated interesting developments in Human Machine Interface technology. Now, it’s becoming more common to see evolved forms of Human Machine Interfaces. More advanced Human Machine Interface examples include high-performance Human Machine Interfaces, touch screens, and mobile devices, along with more traditional models. These modernized interfaces are creating more opportunities for equipment interaction and analysis.

High-Performance Human Machine Interface

Operators and users are increasingly moving toward high-performance Human Machine Interface, a method of Human Machine Interface design that helps ensure fast, effective interaction. By only drawing attention to the most necessary or critical indicators on the interface, this design technique helps the viewer to see and respond to problems more efficiently, as well as make better-informed decisions. Indicators of high-performance Human Machine Interfaces are simple, clean, and purposely cleared of any extraneous graphics or controls. Other design elements, like color, size, and placement, are used with discretion to optimize the user experience.

Touch Screens and Mobile Devices

Touch screens and mobile devices are two Human Machine Interface examples of technological advances that have emerged with the advent of smartphones. Instead of buttons and switches, modernized Human Machine Interfaces allow operators to tap or touch the physical screen to access controls. Touch screens are especially important when used with a mobile Human Machine Interface, which is either deployed through a web-based Human Machine Interface/SCADA or via an application. Mobile Human Machine Interface offers a variety of advantages to operators, including instant access to Human Machine Interface information and remote monitoring.

Remote Monitoring

Mobile-friendly remote monitoring allows greater flexibility and accessibility for operators and managers alike. With this feature, an offsite control system engineer can, for example, confirm the temperature of a warehouse on a portable device, eliminating the need for onsite supervision after working hours. Soon, checking in on a process on your factory floor while being miles away from the facility won’t seem like anything out of the ordinary.

Edge-of-Network and Cloud Human Machine Interface

Edge-of-network Human Machine Interfaces are also in high demand because they allow operators to access data and visualization from field devices. Additionally, it is becoming more common to send data from local Human Machine Interfaces to the cloud, where it can be accessed and analyzed remotely while keeping control capabilities local.

Peering into the Future of Human Machine Interface

On the horizon, leading engineers are even exploring ways to implement Augmented Reality (AR) and Virtual Reality (VR) to visualize manufacturing functions.

As data takes on an increasingly essential role in manufacturing, the future looks very bright for Human Machine Interface. This technology may have come a long way, but its potential for growth remains virtually limitless.

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