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What is a Human Machine Interface? - An Exploration
Briana Watson

Bridging the gap between humans and technology is essential to the creation of any device. Without this connection, it becomes nearly impossible to use these products to their fullest potential. As the Internet of Things (IoT) continues to expand, humans need to be able to understand what the technology can do, and technology needs to be able to give humans everything they need to work with it. It is because of this, that the development of a Human Machine Interface has become an important part of the evolution of technology.

What is a Human Machine Interface?

industrial worker with robotic arm machine Image by Gerd Altmann from Pixabay

Human Machine Interface, also known as HMI, is the physical dashboard or user interface that connects a ‘human’ to the device. Whether this is a system, machine, or something else entirely, it is the point of contact that allows a person to control a device and allows the device to follow a person’s commands. The function of an HMI is similar to that of the Graphical User Interface (GUI) but there are still differences. They often pair well together, though. In fact, it is very common to see an HMI that utilizes a GUI for the visualization capabilities that they are able to provide.


The biggest difference between an HMI and a GUI is how much they are capable of. GUIs are very prevalent in different types of devices within the realm of technology as they make it possible for users to interact with various kinds of software. On the other hand, HMI’s are primarily seen in industrial settings, showing up mostly within machines and automation devices. An HMI will typically utilize a GUI for designs like touchscreen interfaces that let a person send commands to the software and hardware of a machine. While they can often be seen together, and do work well together, it is still important to make the distinction between these two elements of technological design.

How Does a Human Machine Interface Work and What Is It Used For?

HMIs work by creating a usable interface that allows a person to communicate with a device. The simplest way to look at it, is as an input/output device. Information is ‘input’ using the HMI by a person who is operating the machine, and the machine ‘outputs’ the commands based on what information was given. Conversely, the machine may input information from its sensors or hardware that is then output on the HMI for the person who is operating the system to see and understand. Then, combined with programmable logic controllers (PLC), machine sensors are able to record and provide information as it is given and received. This particular input/output relationship is why HMIs are so often seen in industrial settings. In these settings, an HMI is often used to interpret, view, and even control the following information:

  • Production Time
  • Production Trends
  • Visual Data
  • Temperature Control
  • Oversee KPIs

This is by no means a comprehensive list, but it is a good place to start when working to understand the full scope of HMIs. Typically, the complexity of the HMI is determined by how complex the needs and tasks of its machine are. Some HMIs are dedicated to only completing a single function while others are more intricate and are used to complete an array of tasks, control several types of equipment, and record a variety of information to present to its users.

Benefits of a Human Machine Interface

Human Machine Interfaces have become so integral to machine designs in the industrial industry, largely because of just how many benefits they offer. For one, the increased visibility that these interfaces provide allows data to become centralized, easy to read, and ensures that important notifications or changes in production are never missed. Enhanced efficiency provides accurate, real-time data that is especially useful in such a high paced environment. Other benefits of HMI include, but are not limited to:

  • Cost Reduction
  • Improved Usability
  • Improved Time Management

Who Uses a Human Machine Interface?

As mentioned previously, HMI is primarily used in industrial settings. The need to communicate with and control machines is a key part of working within these types of industries, and is why the use of HMIs has become so popular there. Being able to interact with machines allows for an optimal industrial process as well as better control over the final product and the overall safety of the process. HMIs are typically operated by those in the engineering and system integrator roles within an organization due to the level of skill needed to fully understand the system. Some of the industries that use HMIs include:

  • Manufacturing
  • Recycling and Waste Management
  • Oil and Gas
  • Energy and Power
  • Food and Beverage

HMIs are used so extensively in these particular industries because of monitoring ability that they give to engineers and managers. Not only do HMIs direct hardware to complete various tasks, but they allow users to accurately monitor the overall production and adapt to production needs at a moment’s notice. With HMIs added to a production team’s arsenal, efficiency is improved and downtime is often significantly decreased. Maintenance issues also become much easier to address as HMI systems can often tell their operator exactly where any problems are occurring.

However, it is worth noting that HMIs aren’t exclusively seen on an industrial level. As consumer technology continues to advance, the use of GUIs contained within HMIs becomes more and more common. An example of this can be found in most modern home climate systems. Users are able to use an HMI to control their air conditioners and heaters, monitor the temperature in their homes, and adjust those settings according to their personal needs and comfort levels. Another example is home security systems, which are evolving to use HMIs and GUIs to provide increased levels of safety to their alarm and monitoring systems.

The Future of HMIs

What can we expect to come next for HMI? Current trends in tech development suggest a variety of changes and improvements that we can expect to see for this particular bridge between human and machine interaction. One of the first changes we’ll likely see is the incorporation of remote monitoring that will allow operators the freedom to monitor and control machines from different areas. Keeping with this idea of remote accessibility, we’re likely to see further development and implementation of cloud based software for HMI. Data being easily accessible is a must-have for any device, and is especially important for industrial machines that record and store so much information. Being able to access this information anywhere will be a marked advancement for the operators of these machines. Other advancements that are soon to come include: intuitive control panels, stronger touch screens, and gesture recognition.


Here at Total Phase, we are always excited to see what is coming next in the world of technology. As we continue to further develop our own tools, we look to other industries to get a stronger sense of what our customers need to develop their embedded systems. Our line of I2C/SPI host adapters, including our Promira Serial Platform, gives users the ability to emulate and test I2C or SPI devices, prototype systems, or quickly program  I2C and SPI memory devices. These tools combine with software like our Control Center Serial Software or Flash Center Software to give engineers all of the tools they need to debug and development systems that incorporate HMIs. With its growing popularity in industrial and even personal settings, we’re likely to see great things from this particular tool in the continued communication between man and machine.