What Is HMI?

Many times, we heard about machines and the varied technologies that have been used to control and operate these complex machine operations. Engineering technology exists in an increasingly interdependent world. The Internet of Things (IoT) is a dominant trend that connects industrial and consumer products via the internet. Human Machine Interfaces (HMIs) are becoming more refined in order to operate these devices. In this blog, we will learn about such a technology known as HMI technology that allows you to interact and operate with a machine.

What is HMI?

HMI is an abbreviation for Human Machine Interface. A Human Machine Interface (HMI) is a feature or component of a device or software application that allows humans to engage and interact with machines. An ATM machine is a very common HMI that we all encounter in everyday life. Its screen and push buttons allow you to operate the machine in order to dispense or deposit money. Let us now understand industrial HMIs. The automation process in the industry would be impossible without HMI technology.

In the industrial context, HMIs are typically screens or touchscreens that connect users to machines, systems, or devices. HMIs are used by factory operators to control and automate machines and equipment as well as production lines. HMIs can range from simple screen displays mounted on factory machines to advanced touchscreens, multitouch-enabled control panels, pushbuttons, computers with keyboards, mobile devices, or tablets. They may contain data such as temperature, pressure, key processes, and material counts. They can also display very precise levels in tanks and machine positioning.

Whereas previously machine information was displayed on multiple indicators, it is now displayed on a single screen. Only the software and hardware are used to limit the possibilities. Many HMIs can also connect to PLC logic and highlight it on the screen for debugging purposes for maintenance personnel. When compared to connecting a computer or laptop every time, this can save time.

HMI Technology

The Evolution of HMI

In terms of entering input, batch processing was the dominant mode of interaction with machines in the 1950s. Batch processing needed a user to define all of the details and sequence data of a task, which was usually done with a punch card. This punch card was inserted into the punching machine. The punch card was evaluated by the machine, and the results were delivered. Batch processing was not an efficient mode of human-machine interaction because the technique was prone to error. 

Engaging with Machines

A similar process was followed by the formation of command-line interfaces. Command-line processing allows users to interact with machines more interactively by issuing direct commands to the machine. This is accomplished by entering successive lines of text into a text-accepting programme. During the 1960s, this was the dominant mode of interacting with machines.

Using Graphical User Interfaces to Interact with Machines

The next stage of human-machine interaction was graphical user interfaces (GUIs). These interfaces enable end-users to interact with machines through the use of rich graphical elements such as windows, buttons, and icons. This is known as the WIMP model (window, icon, menus and pointer). Keyboards and other devices, such as the mouse, were used to engage.

The Post-WIMP Stage

As the use of computers and technology doubled in modern society, so did the demand for more advanced levels of human-machine interaction. This resulted in the introduction of touchscreens and comprehensible user interfaces, which allow users to interact with virtual objects through the use of a physical handle.


Due to their resemblances and the fact that they work together, HMI and SCADA are frequently confused. In fact, an HMI is quite often used as part of a SCADA system.

SCADA systems are used to manage large systems, such as an entire plant or site. It is a mash-up of numerous other systems, including PLCs, sensors, and Remote Terminal Units (RTUs). A SCADA system is responsible for data collection and recording. It can also control the operation of equipment, sometimes automatically. An HMI, on the other hand, is the interface through which a person interacts with a SCADA system as well as other systems and equipment. Both are critical components of the wider industrial control system. While the SCADA gathers and stores information, the HMI allows users to interact with and manage the equipment through the use of a user-friendly dashboard. They are both required. Without SCADA, an HMI would be unable to display information or control equipment. Users would be unable to see the data collected by the SCADA system or instruct it on how to control equipment without an HMI system.

SCADA and HMI are both elements of the same larger system. SCADA operates in the background, whereas HMI is usually the only element with which users interact. This is why users frequently refer to them together.

Role of Human-Machine Interfaces in SCADA Systems

In order to function properly, most SCADA (Supervisory Control and Data Acquisition) systems rely on embedded HMI components. The SCADA system is the main, overall control system in a factory or plant, and it is in charge of regulating all of the complex operations that are taking place.

Conventionally, to integrate a manufacturing line with an HMI, the HMI had to be linked to a Programming Logic Controller (PLC), and the HMI displayed data from the PLC and gave the PLC user input. These graphical displays were typically very simple.

The basic HMI enables the operator or plant manager to check usual parameters such as machine(s) temperature, processing counts, machine(s) status, and material counts.

Examples of HMI and SCADA

A common scenario incorporating an HMI occurs in many water and sewage treatment plants. Because water treatment involves numerous phases such as screening, pumping, and the removal of various harmful microorganisms and residuals, these facilities frequently face challenges. Furthermore, each phase of the treatment can take place in areas that are hundreds of kilometres apart, making monitoring of equipment and processes difficult.

The SCADA system’s HMI screen is typically linked to the PLC, allowing the operator to remotely monitor water level, pH, water pump, dissolved solids level, or a specific toxic chemical. Much modern industrial HMIs designed for the smart-factory environment are multimedia-rich. They enable users to receive integrated SMS alerts about machine status, email alerts and watch integrated videos of factory floor processes. More advanced HMIs enable remote control over various machines and operations across multiple sites, as well as analysis of factory operations.

Dashboards with manufacturing and plant-related KPIs can also be displayed on HMIs. As new technologies are constantly being integrated, the role of the HMI is rapidly evolving.

Advances in HMI Technology

Improvements in the functionality of HMI technology have resulted from technological advancements and dynamic business needs. Touchscreens, mobile devices, cloud-based HMIs, and high-performance HMIs are becoming increasingly popular.

High-performance HMIs are a type of HMI design method that focuses user attention on only the most important elements. This allows users to see and respond to issues more quickly, as well as gather the information needed to make decisions more easily. The indicators on these HMIs are simple, and the dashboards are devoid of unnecessary graphics and controls. Other design elements are used sparingly so that the user is not distracted from the most important items. 

Furthermore, advanced technologies such as IoT and data analytics are attempting to have an impact on HMIs. HMIs can gather more information and become a subset of the IoT network as more connected devices become available. Advanced data analytics methods used in conjunction with HMI/SCADA software can assist businesses in making the most of the data presented on their dashboards.

Following are the few notable HMI advancements: –

Multi-Touch Screen

Touchscreens became popular with the rise of the smartphone, thanks in part to the multi-touch screen, which allows users to interact with multiple touches and gestures at a certain time. This feature is now accessible in HMIs used in the industrial sector. Here are some more benefits of multi-touch HMI that cannot be ignored.

Enhanced safety in operation

The HMI’s intuitive control means lower error rates. Multi-Touch also supports two-handed operation, which means that users cannot perform certain tasks with only one hand. This feature aids in the avoidance of potentially costly and even fatal errors.

Less training time

multi-touch use aids in reducing training time. Users can quickly learn how to use the system, and less experienced users can handle more projects safely and easily.


Touchscreens can handle harsh conditions better than keyboards, mouse devices, and other controls because they have no moving parts. It means that your equipment will last longer and perform more consistently.


With a touchscreen, process changes with a touchscreen do not necessitate rewiring a control panel. You can easily modify your software instead. Users can also simply build their custom dashboards based on their specific requirements and preferences. 

Remote monitoring ability through HMI Technology

Remote monitoring is another useful feature of contemporary HMIs. Authorized users can access dashboards and reports from anywhere using a browser with modern HMI. This means you can check in on operations and complete operational tasks from a computer in an office, a tablet at home, or a smartphone while travelling. Remote monitoring enables constant monitoring after working hours without the need for on-site supervision, as well as greater control over your processes and improved access to your data.

Advantages of HMI Technology in industrial organizations

As we have learnt lots of things about modern HMI, now it’s our turn to know about the numerous advantages of HMI in industrial organizations. The advantages are-

Increased rate of efficiency

You can use an HMI to monitor production and adjust to changing demand in real-time because it provides constant access to real-time data. Data visualisation, especially when combined with data analysis technologies, can assist you in identifying areas where your operations can be made more efficient.

Increased visibility

A high-performance HMI provides you with constant visibility into your operations. It enables you to monitor the performance of your equipment or facility from a single dashboard. This dashboard can even be accessed remotely. These features enable you to increase your productivity over time and respond to alerts more quickly.

Lower downtime

You can address problems more speedily with alerts on a central dashboard, reducing downtime. Viewing and analysing equipment performance data can also help you identify early warning signs of future mechanical issues and address them before they cause significant downtime.

Enhanced Usability of HMI

HMIs facilitate the viewing and understanding of data and the control of equipment by users. They present data in the form of graphs, charts, and other visualisations, allowing users to quickly analyse it. 

Future of Human Machine Interface (HMI)

HMI will become even more important because data has been becoming more prominent in industrial processes. Technology has advanced significantly in recent years, but it will continue to evolve in the future. 

There are presently a variety of speculations for the next level of human-machine engagement. Cloud computing, cognitive computing, and the Internet of Things (IoT) are all expected to play a role in the evolution of the next level of human-machine interaction. 

Predicting what will come to the fore as the next level of engagement is difficult. However, there is no doubt that the next level of human-machine collaborations will drive productivity in a variety of industries.

More industries are shifting to high-performance HMI, which helps direct users’ focus to only the most important information. This assists users in making sense of all available data and prevents information overload. Multi-touch screens, remote monitoring, and cloud-based systems are also increasingly being used by businesses.

Companies will increasingly use advanced data analytics and artificial intelligence to derive insights from data as technology evolves. These insights can then be communicated to users via HMIs. To create more effective visuals for HMI users, HMIs may incorporate augmented reality (AR), which overlays digital graphics on the real world, and virtual reality (VR) technology, which immerses users in a digital world, in the future. As automation is becoming more prevalent in industrial processes, users can use HMIs to monitor and control automated activities as needed.