Your HMI (Human Machine Interface) for your PLC is critical to your industrial automation’s success. The HMI provides a virtual window into your processes, helping operators keep facilities running safely, securely, and efficiently. Customizing your HMI ensures that it offers the right kind of information but is not so complicated that it overloads the user.
A successful HMI uses visually distinctive and easy-to-understand graphics and makes it a more useful tool in the hands of operators. Everything about your HMI project should focus on making it the best tool it can be by keeping the end-user in mind, avoiding errors and increasing efficiency.
Regardless of the information available on the HMI, there are benefits to optimizing the design. In doing so, operators can see important information like graphs, charts, alarms, and connect with SCADA and MES systems, all in one console.
Emphasis means giving an object, component, and data-point special significance. When focusing on the operator, you design a tool that an operator needs to know to do their job. When appropriately implemented, it conveys information effectively, increasing efficiency, and helps avoid human error.
When determining what to emphasize, specify the information that is most important to the operator. The higher the importance, the more emphasis it should have on the screen. Remember, what is essential for one operator may not be for another, so you may need to customize the HMI for multiple users and incorporate learnability into the design.
Any HMI project focuses the operator’s attention on the information most important to their job. There are four concepts to keep in mind to develop an HMI that works well for your operators. These are size, color, position, and isolation.
Optimize with size
Draw the operator’s attention to essential buttons and sections they use during their job by enlarging a button or area on the screen. Patterns are easily recognizable, but it draws attention to that item when something breaks up that pattern.
Applying this concept to your HMI, the more attention that element will command. When all screen components are the same size, they are easily missed or ignored.
Call attention with color
Just like breaking a pattern with size, different colors draw the eye, and the operator will notice. Complementary colors such as green/red, purple/yellow, and blue/orange are a great way to call attention to essential items.
In an HMI project, color is instrumental in creating alerts. To do this, make sure the color is unique to the screen. If your primary screen color is blue, select an orange color for alerts. A general rule of thumb is to use neutral colors for the main screen and use complementary colors for important buttons or icons.
Position items properly
We typically read left to right and top to bottom. Understanding this concept will help create the positioning on your HMI screen. The best way to implement this concept is to break the screen up into four quadrants.
Because we read left to right, the top left corner draws the eye first. Placing the most critical information in this area helps the operator notice it first. The bottom right section is the last read, so put less important information here.
Isolate for clarity
Isolation is the concept of creating space between items on the screen. When you isolate a specific section on the screen, the eye is drawn to it automatically. When you increase the area around an object, it creates more emphasis.
To do this, make sure your HMI screen isn’t cluttered. The more information on the screen, the more difficult it is to draw attention to essential items. The rule of thumb here is to keep your screens simple, optimizing the emphasis of critical sections.
The Best Approach for Optimizing Your HMI
Your HMI contains lots of information, but some sections are more important than others. Paying attention to the design concepts highlighted above, you can ensure that your operators will see the right information at the right time and in the right way.
No matter what your operating processes are, you can avoid errors and missed alerts. When an HMI is not optimized for the viewer, it becomes more of an obstacle than a benefit.
When creating your HMI, ask yourself, “How can I maximize the operator’s efficiency?” When you focus on the answer, you develop an HMI with the operator in mind.
For expert assistance in choosing, developing, and configuring a PLC and its HMI/IoT system, reach out to Browning Electric Co. We’re proud to help companies streamline their industrial processes and collect valuable data from their devices.