top of page
  • Writer's pictureRick Forsgren

3 Pillars of Effective HMI Design in Packaging and Beyond

HMI establishes a machine builder’s brand, so any upgrade requires a balance of optimal user experience, hardware options and upstream communication

An industrial control panel with intuitive UX
As the main point of interaction between the machine and the equipment end user, the HMI essentially is the machine builder’s brand. So it’s important to offer a great UX, rugged hardware and simple upstream communication.

For machine builders in all industries, differentiation over the competition is a source of pride. Maybe you like to be known for high throughput, 24/7 reliability, flexibility with easy changeovers or sheer speed to market for a new design. Maybe you enjoy a reputation for always using the latest mechatronics, AI, vision technology and so on.

Those are all great competitive advantages. But they do little to establish a cohesive brand among a customer’s execs, engineers and machine operators. Nor does a fancy logo or corporate promo items or sleek copywriting.

The most important aspect of any OEM’s brand probably wouldn’t make most people’s top 10 list. Still, the human-machine interface (HMI) is the most critical component for ensuring a positive relationship with your brand. This key combination of hardware and software is the first impression your customer has of the machine’s functionality and ease of use. However, it’s often the last aspect considered in an application, and many companies simply slap on the same drab plastic panels that are about as exciting as an old analog TV.

Let’s explore why this is and what you can do about it whether you work for a machine builder, system integrator or end user of equipment. To help evaluate any HMI update, it’s helpful to consider at three pillars of effective HMI.

Pillar 1: Software geared toward UX

Much has been said – maybe too much – about the iPad generation. But we can all agree that the rise of tablets and smartphones has played the dominant role in setting user experience (UX) expectations, even in industrial settings. Back in the day, machine operators had to receive extensive maintenance training and rely on PLC programming knowledge to make changes to (or just make sense of) cryptic interfaces with limited troubleshooting assistance. With today’s continued labor shortages and reduced automation expertise on the plant floor, that’s not an option. Despite these harsh realities, this was never a good approach to machine operation due to unnecessary downtime.

TwinCAT HMI software on a computer monitor
To create optimal UX, TwinCAT HMI supports programming in a graphical editor familiar to controls engineers and offers standard tools to implement CSS themes and build additional programs with APIs.

Any contemporary HMI should offer simple, intuitive software navigation with fewer pages to navigate and multi-touch functionality to find everything faster. The design, on-screen text and labels should be created for users to understand in their local languages, with easy-to-understand terminology, controls and troubleshooting measures. There should be no “engineer speak” in the headings, and the HMI should offer variable parameters to allow non-programmers to make changes intuitively without having to get anywhere near a PLC to edit the machine code.

Developments in web-based HMI open up even more possibilities for machine operators. This takes the bring your own device (BYOD) approach to the plant floor. With HMI software built using modern web development standards such as HTML5 and JavaScript, OEMs can implement a responsive UX that automatically scales and reformats based on any piece of glass – whether it’s the industrial HMI in landscape or portrait orientation or those previously mentioned smartphones and tablets. The ability to take your machine’s HMI anywhere communicates a clear wow factor and top shelf flexibility for the machine’s authorized operators.

Beyond usability, a better HMI helps users manage parameter changes consistently, ensuring no damage is done and safety protocols remain in place. A modern UX also enhances diagnostics, giving more context to error codes and helping users quickly troubleshoot problems. You can even embed instruction videos or PDF documentation – for example, how to fix material feed issues on a Vertical Form Fill Seal (VFFS) machine. The more actionable information at the machine that’s easy for everyone to understand, the greater time savings and overall equipment effectiveness (OEE).

Pillar 2: Hardware for durability and appearance

The main operator interface hardware on the machine has to be tough. Screens have to be resilient to constant use and harsh environments where bumps, scrapes and blunt force mishaps are all possible. The leading HMI designs today incorporate all-metal housings that are either milled out of solid blocks of aluminum or encased in steel. This ensures the displays can take more of a beating compared to plastic panels that are far flimsier and more prone to cracking and breaking. Beyond the build, panels with rugged metal housings should be ruggedized for constant vibration and extreme temperatures. For applications that are wet, dusty and a little messy, like food, beverage and pharmaceutical production, IP65-rated panels with stainless steel housings and bezels can get wet and be wiped down in typical hygienic cleaning processes.

Beckhoff control panels in different sizes
Scalability is key for HMI software and hardware, enabling use across various sizes of industrial-hardened touchscreens and mobile devices.

Some machine builders and integrators may think they only have the choice between vanilla and vanilla for their HMI screens, but they should look to vendors that offer a comprehensive array of screen sizes and orientations. While offering better looking, more durable and more reliable panels, there are vendors out there that also offer durable HMI hardware with screens that range from 5.7-inch all the way up to 24-inch – and a whole lot of options in between. Widescreen formats have become quite popular, but it’s just as possible to standardize on panels in portrait orientation in several screen sizes. However, some vendors understand that older formats such as 4:3 are still preferred by some machine builders and continue to offer options there. Best of all, there are options to include capacitive multi-touch functionality in almost all of these screen sizes and orientations to keep up with all the exciting developments previously discussed in HMI software technology.

While it’s important to ensure that HMI hardware is designed for rugged operation in the here and now, choose vendors that can ensure long-term reliability and availability so the hardware can last within the typically long lifecycles of machinery installed in the field. This reduces redesign requirements and helps make any HMI maintenance, repair or replacement with the same hardware viable for decades.

Pillar 3: Upstream communication

Functionality shouldn’t stop at the plant floor, not even at the remote machine control level. Modern HMIs should deliver the upstream connectivity necessary for manufacturers to create real business intelligence or calculate OEE, adding value for end users. This includes the ability to send information from the machine upstream for evaluation at the SCADA, MES or enterprise levels. It could also encompass using artificial intelligence (AI) or machine learning (ML) to optimize performance, throughput or energy efficiency.

Beckhoff HMI
With a 19-inch, multitouch screen, custom push-button extensions and stainless steel housing, the Beckhoff CP3918 Control Panel offers robust HMI hardware for ProMach Filling Systems’ XACT-FIL™ machine.

Here the power of your overall automation platform is just as important as the HMI software. Can you easily pull data from across the entire machine or plant – over EtherCAT, EtherNet/IP, PROFINET or other networks in the field, plus vertically with MQTT, OPC UA, AMQP, etc.? Can you bring a newly optimized control algorithm down via ML and implement it on your line quickly and easily? Can you easily and securely log into your machines installed around the world for remote service? As the digitization of manufacturing only accelerates, HMI can no longer simply be a static menu. It can be a gateway from the plant floor to the cloud and promote harmony of machine-level systems with higher-level operations.

And speaking of digital transformation, that mundane dynamic of having operators and maintenance personnel trudge back and forth between the HMI and the PLC to figure out an error code is simply no longer viable. I can guarantee that old routine isn’t part of anyone’s digitization game plan.

Choose your HMI technology wisely

So what does all this look like for the controls engineer, then? They should seek out HMI software that allows for programming in HTML5 and other common web-design standards. Your software should also offer superior portability so you can run the same program on the next generation of hardware, rather than needing to write a new program every time you make a change. Bonus points if all this is integrated into a universal automation platform and engineering environment that encompasses everything from HMI to PLC to robot kinematics to IoT. The resulting differences – both on the exterior and under the hood of the machine – can be awe inspiring for end users.

Want to upgrade your HMI hardware and software to make a great impression on customers? Contact your local Beckhoff sales engineer today.


Rick Forsgren of Beckhoff USA

Rick Forsgren is the Packaging Industry Business Development Manager at Beckhoff Automation LLC.

A version of this article previously appeared in Control Engineering.


bottom of page