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Are smartphones the new human-machine interface?

Industry is starting to switch to smartphones as a primary HMI tool on the factory floor. Neil Ballinger takes a look at where the trend leads

Neil Ballinger
|Nov 15|magazine10 min read

In this new age of working, plant managers and engineers alike are switching to smart phones to see how the various machinery on their factory floor are operating. But does this mean that the traditional human machine interface (HMI) is about to vanish?

Many industrial automation manufacturers, such as ABB, Haas, Rockwell and Siemens, have started introducing smartphone connectivity to their machinery. Linking an assembly robot or a CNC machine with your smartphone offers a range of benefits, such as remote control and status alerts. As more and more machines are being connected in this way, one would be forgiven for thinking that smartphones are the new HMI.  

Tough and ubiquitous

Personally, I believe HMIs are here to stay and are even going to become more widely used. If you think about it, almost everything has a HMI — from a coffee machine to the most sophisticated assembly line. Using a HMI is beautifully straightforward. Unlike with a smartphone, you don’t need to take your gloves off, pop a pair of specs on, wait for the app to load or navigate a complicated menu.

It’s not just their simplicity, but also their ruggedness that make HMIs such an invaluable tool. Most liquid crystal displays (LCD) on HMIs can be operated with your gloves on. Moreover, the glass screens of phones etch easily, for instance when they come into contact with metal fragments or chemicals. The screens of traditional HMIs are thus uniquely suited to a manufacturing environment.

Trouble shooting

HMIs are not without their problems of course. When the screen begins to flicker, becomes less responsive, or the device needs several attempts to power up, then the user experience is severely impacted. 

The good news is that many of these issues can be easily fixed. Firstly, a flickering screen is a sign that the HMI backlight needs replacing. Second, even though HMIs are designed for tough environments, LCD screens are actually very sensitive. Only use your fingers to operate it and if the touchscreen becomes unresponsive, have it replaced.

If your HMI needs several reboots before it starts, then this could either be due to a software issue or a problem with the internal power supply. The manufacturer, or a good automation parts supplier, should be able to help you fix this. It’s important that operators recognise this problem early and seek expert assistance before the HMI fails completely.

One of the major advantages of a HMI over a smartphone is that nearly all its parts can be replaced individually. At the same time, some functionalities that are used in smartphones have now been introduced to HMIs. Operator controls can now be animated and graphics enlarged or rotated to provide for better visibility of processes.

The HMI of the future

HMIs are evolving all the time. The long-stroke keys have almost entirely disappeared in favour of panel-based solutions that drastically reduce the cost of installation, because only one wire is required instead of one physical connection for each individual button. 

With the Industrial Internet of Things (IIoT), machinery and robots rely increasingly on complex real-time algorithms that require internet connection to crunch all the data involved. So, HMIs are now only one of several ways of managing the data input and output of a machine. 

Introducing smartphone-based steering of machines sounds like the next step in this process. Smartphones are indeed very useful for receiving alerts, for instance on downtime. Such alerts are managed with an app-based solution and usually necessitate linking your machines to the internet. However, relying completely on smartphones risks overlooking the central position that HMIs hold in manufacturing.

The rise of tablets

If you’re still not sold on sticking with a traditional HMI, tablets offer a way to combine the advantages of both smartphones and HMIs in one single device. Tablets can be toughened up to withstand the wear and tear of an industrial environment. Also, a special software can be uploaded that has the same access, control and visibility as the existing HMIs. 

Yet the fact that tablets are decoupled from the machine offers the benefit of standardising controls, software and hardware replacements across the entire factory floor. Different types of machines no longer need to have their own HMI attached to it. Moreover, tablets can be fitted with improved software security and can be used to specify exactly who is authorised to access which machine.

It’s clear that the future of HMIs is across multiple types of device. Newer machines will allow for tablet-based steering and smartphone connectivity, whereas older equipment still relies on traditional HMIs. Therefore, it is important that the legacy technology is managed effectively alongside the latest innovations.

Neil Ballinger is head of EMEA at automation parts supplier EU Automation. 

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