Published: 21/01/2022
A Human Machine Interface (HMI) unites person and machine as a communicative device most commonly used in industrial settings. These devices are usually linked to a Programmable Logic Controller (PLC) which then monitors and controls an automated process. The HMI generally comes in the form of a touchscreen, allowing the user to communicate with the PLC, providing commands for the device to follow. The PLC also acts as a translator as information travels to the HMI and is translated into a visual language for the operator to understand. The HMI is used for monitoring the process and tracking data, however more sophisticated devices can even power up or down machinery and adjust production speed.
All in all, implementing this device greatly optimises a process with great benefits to the people involved. Instead of the user walking throughout a production line to determine inconsistencies or issues, every piece of data is visible in one convenient location, displaying graphs and charts. These operators have kicked the notepad and pen to the curb in favour of this automated solution.
In the world of HMIs, there are three prominent variations including the overseer, data handler and pushbutton replacer.
Firstly, let's cover the overseer and no, we are not talking about Shyamalan’s “Unbreakable” fictional superhero. The overseer HMI usually uses the Microsoft operating system and SCADA to function, monitoring and controlling complex and extremely large systems. These interfaces can even control an entire site, providing integral diagnostic data.
But what is SCADA?
SCADA is an acronym for Supervisory Control and Data Acquisition and although very similar to the HMI, each has their own unique capabilities. While HMIs are all about conveying an accurate visual portrayal of data and act as a supervising support system, SCADA systems offer greater data capacity. Therefore, when the two come together, you have yourselves a recipe of visual communication and data storage all rolled into one.
The data handler is as you would expect, all about data. If you require constant information from your production line, the HMI LED display will provide a visual representation and summarise the status, saving valuable time. Equipped with a hefty memory capacity, these devices can be used for recipes, logging valuable data and for controlling alarms.
The goal of any automated device is to streamline and simplify an industrial process and this is exactly what the pushbutton replacer HMI achieves. In years gone by, there were numerous pushbuttons throughout a production line, each present to control a different element of the process. Nowadays, this single button has the power to control all functions.
By a country mile, the greatest benefit of a HMI is the user interface. This usually includes a colour coded system which identifies if there is a fault or if everything is plain sailing along with visual aids to contribute. This feature alerts the operator to errors promptly, saving valuable time in these scenarios. HMIs are so incredibly efficient, capable of reducing manufacturing costs due to its speedy fault finding capabilities. This intrinsically boosts productivity, automating tasks which would have once taken perhaps double the time, giving employees the time to put their skills to work elsewhere.
However, the benefits do not end there. HMIs often include remote I/O devices and other pieces of equipment which communicate. The addition of a HMI enhances this communication and with their varied compatibility, this can benefit a variety of automated solutions. In a world where Industry 4.0 is a constant topic of conversation, as a device attributed to the Internet of Things, your HMI also allows for network monitoring.
In a traditional industrial environment, there would be sensors aplenty and if a single one was out of action, serious faults could occur. A HMI replaces each one of these sensors with all information being visible on one screen, meaning reduced hardware costs and minimised space wastage.
Many HMIs are capable of recording valuable data, one of the world's hot commodities. By recording this information, the operator is able to reference it when an issue arises. For instance, if a breakdown occurs, the data can be reviewed which will highlight any irregular operational patterns. As the HMI translates data into a visual representation, the operator will also be able to view machinery schematics and feed it instructions. Imagine! No walking down the production line to press the big red button to power down, just head over to your HMI and that automated device will do the work for you.
HMIs date back to the 1940s when batch interfaces were introduced. These devices were not the interactive pieces of kit we know today but instead the operator would input the job details and would then receive output data once complete. No further input could be made once the process had begun meaning this was a far less flexible solution than the technology on offer today.
Later down the line in 1969 it was not just the moon landing making headlines. The world of HMIs was becoming an increasingly innovative space with the introduction of the Command-Line User Interface. This device would follow the same premise as the Batch Interface but it would also prompt the programmer for further input. For this reason, it was adopted by engineering and scientific professionals and is still commonly used. The most renowned example of this device is the Windows Disk Operating System, launched in Seattle and designed specifically for the IBM PC and gradually becoming king of the technology space throughout the 80s.
Just over a decade later, Graphical User Interfaces (GUIs) were introduced whereby the operator could input data using gestures sketched with a mouse or stylus, translating to a graphical output on the monitor. Studies show that “over 90% of information that is processed by the brain is visual. Furthermore, humans process visuals 60,000 times faster than text.” Moving away from text commands, as highly visual creatures, it is clear to see why humanity is embracing the GUI.
HMIs work in harmony with many different industries and applications, communicating with other devices to enhance productivity and provide valuable insights into the automated industrial process. From oil and gas, food processing and waste water to manufacturing, energy and transportation, the applications of a HMI knows no bounds.
We know where this technology all began but over time, operational requirements have changed, demanding a higher calibre of HMIs with even greater capabilities. While they simplify a process and contain control mechanisms in one convenient location, there will however be greater strain of your Human Machine Interface. Knowing how much responsibility the HMI shoulders, the idea of it failing is somewhat terrifying, however the device knows its limits and will notify the operator when servicing is required. This ability means no unexpected downtime, allowing you to plan your preventative maintenance.
There are some key things to keep on the lookout for when identifying HMI faults. Whether it be a cracked screen, reduced level of brightness or pesky unresponsiveness, our team has you and your repair needs covered.
Northern Industrial is well experienced at replacing touch screen glass. We stock replacement glass for most of the major touch screen brands including Siemens, Allen Bradley, Omron, Schneider and Mitsubishi.
An unresponsive touch screen is only an impatient person away from becoming cracked or broken. Before that happens, we can replace the touch membrane in your HMI to bring it back to full sensitivity.
A flickering or extremely dim screen can be the result of a poor connection or faulty bulb. We have a wealth of experience in replacing backlight inverters and hold stock for most of the leading brands of industrial monitors to ensure fast turnaround times.
Faulty displays cover a wide variety of issues. The problem can be related to the communications rather than the screen itself if it is failing to even switch on. Whatever the problem, we can help. We keep replacement HMI components in stock for a wide range of operator panels. So we can offer a quick turnaround for many faulty displays.
Having those irritating lines across your operator panel display is another issue with HMIs and industrial monitors. They can be caused by a variety of issues from simple loose connections to built up ingress and more serious panel damage.
If you are having trouble with any software on your HMI operator panel give us a call. We can assist with tasks such as cloning hard drives and reloading software to get your HMIs back to full functionality.
The divide between Panel PC and HMI has become increasingly blurred over the past 20 years. Most operator panels have programs, parameters and settings stored onboard which can cause serious problems if lost. That is why we always backup your operator panel’s parameters when possible.
As with drives and other industrial equipment, touch screens and HMIs also have components that degrade with age, eventually leading to the failure of your operator panel.
These components include electrolytic capacitors which can dry out or leak. When capacitors dry out they usually cause faults that are initially intermittent but then become more permanent. Leakage onto the internal circuit board can short between tracks and also cause catastrophic results. These problems are avoided easily with a preventative maintenance service and is why we include them with every HMI repair.
From compact LCDs to large CRTs, we support a vast range of current and obsolete HMIs. We have made our HMI and touchscreen repair service easy and hassle free. With our unique No Fix No Fee promise means if it is beyond repair, you won’t pay. And what’s more, with your two year warranty, your repair will be guaranteed to withstand the test of time.
If you'd like to learn more, click the button below and one of our helpful friendly team will be in touch. Alternately you can reach us by phone on +44 800 234 3747
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