Touch Panel - Basic Properties, Terminology and Theory
What is a Touch Panel?
Touch Panel is a term for Human Machine Interface (HMI). Sometimes referred to as touch screens, this electronic interface replaces pushbuttons, lights, gauges and other traditional hardwired devices. The most popular is the dedicated operator interface systems because they are easy to use, fully integrated and cost effective.
Touch Panels are available in panel mount or stud mount, monochrome or 256 color screens ranging from a two-line display up to 12.4 inches with excellent visibility. Choose from stand-alone controller or units that communicate with other devices like PLCs.
Whether replacing hard-wired pilot devices and pushbuttons or providing machine control and even SCADA functions, Touch Screens can be used in a variety of applications. From monitoring and diagnostics, as well as operator controls for critical start/stop, ramp/jog and set point adjustment or simple message displays, Touch Screens offer a reliable and safe interface for a wide range of industrial applications such as:
- Discrete manufacturing machine diagnostics and controls
- Oil platform monitoring and control in the petroleum industry
- Central and remote water and wastewater control panels
- Monitoring and control panels for local facilities/air handling equipment
- Tire manufacturing mixing and building processes
- Industrial and commercial power house controls; building HVAC controls
- Material handling and palletizing monitoring and control
- Automotive press and machine parts controls
Top 10 Tips for Touch Panel Design
Communicate clearly and configure quickly. Those are the dual goals of touch screen design. Accomplishing those goals depends on the techniques you choose and the tools you use. Here are ten quick tips for making sure your next operator interface project is a success.
- Color Scheme Simplicity - Lay elements on a screen with a neutral color like gray. Highlight items that need attention with a bright, bold color, such as red or green. The neutral color minimizes distraction when an operator is doing their normal job, and the bright colors help to draw operator attention to extraordinary circumstances.
- Information Simplicity – Don't crowd the screen with information – place only the information for the current task. More information than needed on screens forces an operator to search for the information they need. This could lead to an operator pressing a similar button and making an error, or increase operator time for problem solving.
- Consistency - Have a consistent set of menu buttons to help operators navigate easily from screen to screen, and maintain their location on each screen. This makes operations simple to understand and eases training.
- Functional Separation - Separate operator screens from maintenance and supervisor screens. Consider who is using the device the majority of the day and modify the screens for that user for optimal efficiency. In relation to Tip #2, Information Simplicity, this enables you to create a separate set of screens for a particular user, if appropriate.
- Test Your Knowledge - Capture how many times a button is pressed, a page is changed, which page is used most, etc. Reviewing this data may surprise you. You might find that a piece of information missing on the main page is more important than you thought after your review. This process allows you to fine tune your application and help operators spend less time navigating from screen to screen.
- Multi-language Considerations - Make text areas large enough to accommodate various languages because some languages might often use a larger text area than the English equivalent once they are translated.
- Watch Your MLAs - Multi-letter acronyms and other abbreviations only work when all users understand their meaning. Spell out acronyms whenever possible. If you don't have enough room to place the actual phrase, note that your screen might be too crowded or too small.
- Use Images - Pictures and illustrations a great way to quickly draw a user's attention. In a pump application, for example, use an illustration of the pump itself and highlight specific areas that need maintenance or adjustment.
- Group Data Together - Place elements associated with image close to the drawing. This could include the start and stop buttons and readouts for current, temperature, volts, hours run, etc. Placing this information elsewhere on the screen can lead to confusion and limit operator productivity.
- Plan for Change - Assume that the application will eventually be used on a different size display. Prepare by keeping elements on the screen at a high contrast to the background. For example, use a black background and light-colored elements in your base design. This will be very visible on both color and grayscale displays.
Employing these tips and staying focused on the user will help you provide a useful, efficient application. Choosing the right tool can also help, because it will support the best practices described above.
Many analog Touch Screens have macro ability that can store application recipes, images, historical trends and alarm data. Select from a wide assortment of choices to fit your application.