Human Machine Interface (HMI) is any interface that allows humans to interact with machines. It enables a user to communicate with the machine. A properly designed HMI solution enhances productivity for the operator. HMI devices can be as simple as a switch controlling a motor or can be as complex as multi-touch-enabled control panel. With the development of modern technologies, the way we interact with devices has also changed.
Various HMI solutions for machines
- Membrane Keyboard
Membrane keyboards are characterized by the use of keys that are pressure pads with symbols printed on them. They are made of three different layers, which are made of very flexible materials. Beneath these layers are conductive traces, which trigger the appropriate command when the user presses a key.
Membrane keyboards are thin and have a very compact design. They are waterproof and have a longer life span. Backlighting features can also be provided for these keyboards.
2. Capacitive Keyboard
Integrating capacitive touch sensing is a new way to improve HMI features. The capacitive touch-sensing technology helps to create more elegant touch interfaces compared to traditional mechanical buttons. The capacitive touch sensors can be designed in a variety of shapes, sizes, configurations, and materials to suit various products and different interface functions. Capacitive sensors are preferred for various applications as they are versatile, reliable, robust, low cost and also are very easy to implement. Backlighting features are one of the highlights of Touch sense keyboard.
3. Metal Keyboard
Metal keyboards are made using stainless steel material or aluminum. This makes them very tough and thus they can be used in very harsh environmental conditions. They are waterproof and vandal proof. These types of keyboards are especially used in Petroleum industry, Aerospace industry, Public Utility systems (Kiosk and ATM machines), Pharma equipment, etc. AES encryption can also be provided in metal keyboards which make them perfect to be used in defense industry.
4. Silicone Rubber Keyboard
Silicone Rubber Keyboards are high quality washable keyboards that are flexible, waterproof and rated the best where frequent cleaning of keyboards is required for example in medical industry where the risk of cross contamination is higher. Silicon can be molded into any shape and size as per the user requirement. This type of keyboard can also be offered in a variety of colors to add to its aesthetics. It also has an advantage to be used to make illuminated keyboards.
A perfect HMI should have the following characteristics
- Should be user friendly
- Should be able to work in harsh environments
- Excellent durability
- Strong graphic clarity with back lighting options
- It should be able to communicate with major communication protocols
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