When we talk about packaging machinery or packaging equipment, we usually put an emphasis on the machine speed, its features and the range of applications. That is why we decided to use this blog post to discuss the importance of the HMI (Human Machine Interface). After all, no matter how advanced a piece of packaging machinery is, it still needs humans to operate it, which means that the packaging efficiency greatly depends on the operator’s ability to use the machine easily and intuitively. In the following lines, we will go through a short history of human-machine interfaces in the packaging industry and explain the most important aspects of HMI.
A LITTLE BIT OF HISTORY…
Put simply, “HMI” is the medium by which an operator interacts or controls the packaging machine or the entire packaging process. Many years ago it consisted of indicator lights on a control panel and hard wired push buttons, without any sort of visual display. An operator had to rely only on constantly looking at the packaging machine or the process, or listening to the sounds of feedback and alarms while pushing control panel buttons to control the process. As technology advanced, text panels or Alpha-Numeric based operator interfaces emerged and replaced some of the hard-wired push buttons and indicator lights. Now, the operator was able to read pre-programmed messages displayed on the LCD screen, which gave a little bit more visual information about what is going on with the packaging process or the packaging equipment. This was a huge advantage. With further technological development, more refined control systems and visualization products were introduced, starting a revolution in industrial automation. Hi-Resolution and touch screen graphical displays replaced text panels which provided programmers with the flexibility to design a visually pleasing, more informative screen. More importantly, the user or operator could know what was going on in the process without having to scan the entire facility. Everything that the operator needed to know was displayed on the graphical interface in front of him.
WHAT IS A GOOD HMI?
A well designed HMI should have the following characteristics.
- It should communicate with all major brands of PLC’s with their respective protocols.
- Should work in harsh environments.
- Should have rich graphics and good backlit display.
- Should have data logging capability.
- Most importantly, packaging machine software should be user-friendly.
- A well-designed HMI should do more than just control the packaging process. It should provide an operator with the bird’s eye view of the entire process while being safe, reliable, and cost-effective. The HMI is the principal point of contact between the user and the packaging process, so it should perform all functions with minimal effort, increasing packaging productivity to the user’s satisfaction.
Providing an operator with information is the basic function of displays in an HMI application. Displays have come a long way since its invention. During 1990’s LCD (STN / TFT) displays were a standard. The trouble with these displays was that they were operating only at normal temperatures. If the temperature gets too cold or hot, these would stop working. Fortunately, display technology has evolved since the ’90s. Now, most of the HMI manufacturers use LED backlit high definition displays, which are not only durable but can function in a wide range of temperatures.
Most manufacturing production and packaging floor/environments present a number of challenges for HMI’s. Good HMI’s should be at least NEMA 4/4X, IP65 rated, which means it should protect the inner electronics from moisture, oil, dirt, and gases. The best HMI is usually conformal coated, which means it can withstand excessive heat, cold, shock, and vibrations.
DESIGNING A PROJECT
While designing a project to control a particular packaging process, we keep in mind what kind of visual, auditory or tactile feedback is best suited for that application. How many screens are necessary, how many objects are the best fit for one particular screen? For us, simplicity is the key. We try not to crowd a screen, or fill the screen with an irrelevant group of objects that will force an operator to spend his time searching for relevant information. Special attention needs to be given to alarm reporting as well. If there are any alarms, they should be distinctly displayed on the screen to catch the operator’s attention, so the operator is informed that the error has occurred, where the error is and how to solve it.
At Nortech Packaging, we strive to utilize the HMI to make the operator progress through it intuitively and logically.
So if you are in a search for fast, efficient and, above all, user-friendly packaging solution, search through our website and don’t hesitate to get a quote!