What is HMI and How Can You Choose the Best HMI Solution?

Choosing the best HMI panel solution doesn’t have to be hard. It all starts with your requirements. How will it be used? Who will be using it? What inputs and outputs do you need? Where will it be installed?

First, let’s start with the basics.

What is HMI?

A Human Machine Interface (HMI) is a user interface most commonly used in industrial manufacturing and automation environments. An HMI allows operators to monitor and control machinery using visual representations of the components in real time. It also enables operators to optimize efficiency by providing insight into mechanical performance and progress.

What is HMI used for?

HMI solutions are most commonly deployed to control complex manufacturing and industrial automation systems by relatively few operators. Often the operators use SCADA (Supervisory Control and Data Acquisition) management software such as Ignition. Manufacturing facilities of every kind have adopted these graphic systems due to their reliability and ease of use.

HMIs are used to:

• Track production time and trends
• Enable automated control and offer feedback on those automated control systems
• Observe system inputs and outputs
• Monitor system health and performance

Since HMIs typically offer a visual representation of the system or systems being controlled, training is much easier and operators have intuitive insight into the status of equipment and production.

The best HMI is built for durability and a long lifecycle

In the past, desktop computers were commonly used for HMI systems because they offer a familiar interface and control via mouse and keyboard. However, consumer desktop computers lack the durability and longevity required in industrial environments. Dust, debris, and wide temperature variations are common environmental factors in those settings.

The best HMI can withstand an extreme environment and offers a long lifecycle. For your HMI panel PC,  you can select an industrial all-in-one panel PC or build one by combining an industrial or rugged computer with a separate touch screen display. When space is tight, an all-in-one HMI panel PC is often a good choice. However, if you want the flexibility to swap out components, choose a modular build-your-own approach. 

For more information on how to choose a panel PC for your HMI solution, check out our blog on the 7 step process to select a Panel PC.

Touchscreen options: capacitive vs resistive

With the proliferation of industrial HMIs comes the need for more and more advanced touchscreen systems and software. The two primary touchscreen technologies for HMI applications are capacitive and resistive, and OnLogic offers options for both types.

Capacitive touchscreens use the human body’s electrical field to process input, similar to many of today’s smartphones. Capacitive touchscreens are frequently used for installations that require highly accurate touch sensing or multi-touch capabilities (such as pinch to zoom), so they are frequently used for kiosks and interactive digital signage.

Resistive touchscreens rely on physical pressure to transmit touch data. Since resistive touchscreens can be used while wearing gloves, they are a great choice for industrial automation, food processing, and healthcare applications. They are also a good choice when a more tactile interface is preferred.

What are the different types of HMIs?

There are three main types of HMIs, each with different capabilities that are suited for different applications. Understanding the difference between each type of HMI is critical in making sure the one you choose is well-suited for your unique application.

Pushbutton Replacer HMI

Pushbutton replacers take the place of manual buttons. Instead of having potentially hundreds of buttons, switches, and LEDs on a control panel, you can have a visual representation of all of these on one screen. Because pushbutton replacers allow for more controls in a considerably smaller space, these types of HMIs are often used in industrial and other space constrained settings.

Data Handler HMI

Data handlers are often used in applications that require the constant gathering and monitoring of data. Because data handlers are responsible for processing large amounts of data, they often come with large capacity memories. This makes data handlers ideal for applications that require high amounts of data collection from machinery.

Overseer HMI

The Overseer HMI is ideal for MES (manufacturing execution system) and HMI SCADA applications. The most visual of the three, overseer HMIs offer an intuitive graphical user interface (GUI).

What should you consider when choosing an HMI?

With so many different types of HMIs that are all best suited for varying applications, finding the right onefor your solution is key. There are a few things you should consider. Where will the HMI be mounted?  What are your input and output requirements? What is your power source?

OnLogic’s line of HMI solutions are engineered with reliability and flexibility in mind including a variety of mounting options and legacy I/O options to enable connectivity to a broad range of devices. We offer solutions that are resistant to:

• Vibration and impact forces
  • Check out our customer story on SAT Technologies. They mounted a panel PC on a forklift that is subject to sudden movement and vibrations. With their solution, the panel is used to provide instructions to workers on the best way to stack a pallet.
• Moisture
  • In many industries, such as the food industry, panel PCs have to be wiped down and sometimes even hosed down. That’s when an HMI with an IP65 rated front bezel is essential.
• Temperature extremes
  • In energy and heavy industry applications like oil and gas production, panel PCs with a wide operating temperature range allow you to be able to remotely monitor assets from practically anywhere, from the desert to the arctic circle.
• Airborne particulate
  • In manufacturing and food-production environments, airborne particulates can get into panel PCs and cause malfunctions and damage. Fanless and ventless panel PCs offer reliability in environments where airborne particulates are high.
• Fluctuating input power
  • Power issues including spikes, interference, or frequent power loss can create issues in any environment. We can work with you to meet your power requirements. And in the case of power loss, many OnLogic computers have the capability to automatically reboot. In fact, auto power-on is just a setting away.

Once you understand your requirements, we’re here to help you choose the best HMI solution. Contact our technical sales staff today!

Editor’s Note: Inductive Automation has ended their Ignition Onboard program. Ignition licenses must now be purchased directly through Inductive Automation. While the IGN versions of our solutions are no longer available, our computers remain a great fit for use with Ignition software. Explore our recommended hardware here.

This blog was originally posted on July 8th, 2020. It was updated for content on May 2nd, 2023.