By Robert Davies, Marketing Manager
EAO Ltd And David Pearson, Technical Director Anglia Components
The design of HMI’s are constantly evolving, with technological and ergonomic trends driven by the developments in consumer electronics and automotive technology. Whilst the touchscreen might seems to be ubiquitous, the increasing number of machines and electrical appliances in daily use means that there more products than ever that need HMI’s – and often a touchscreen does not meet all the operational needs, or it may not be commercially viable.
Modern equipment, must now be designed for daily use in whatever environment the user wants to operate it in, so there is a drive for compact equipment that can be used even in challenging conditions. Take the example of mobile phones that are now designed to be waterproof and impact resistant.
In the industrial and professional equipment markets, HMI’s are designed to be reliable, to last for the lifetime of the equipment and must provide the user with an intuitive and positive operator experience. Other products, for example ticketing, public transport and public access systems are used by the general public and must have vandal resistant tactile HMI’s that also take into account the needs of disabled or partially sighted users.
HMI’s incorporating electromechanical switches can help to provide an intuitive interface with a positive tactile and visual feedback, where each individual equipment function can be easily selected from clearly labelled buttons without the need to navigate multiple menus within a touchscreen.
Evolution of electromechanical switches for different markets and applications.
In industrial applications such food processing, or machining operations HMI’s operate in aggressive environments, where the equipment is subject to harsh daily usage, by operators using gloved hands and is then followed by intensive cleaning operations. Here, rugged industrial switches offering full switch travel and tactile feedback are essential for intuitive operation, but they must also be durable and resistant to hose down or jet washing. Switches with a metal construction option and with IP69K jet wash protection such as the EAO series 45 are ideal for these applications. This new range is designed to last for up to 10 million operations, includes every conceivable switch type and offers easy single point one hand installation. Rugged construction, reliable switching, long life LED illumination and easy low cost assembly give a competitive full life cost for a premium quality device that can last the lifetime of the equipment without the need for costly maintenance and service visits.
In professional equipment applications the trend towards attractive, compact and ergonomic design has forced the development of new electromechanical switches that meet the needs of today’s product designers. HMI’s now need to be increasingly compact and produced to fit in to small spaces or enclosures on the front operator panel. The use of mixed technology; touchscreen and electromechanical switching placed together means that a switch often needs to be close in depth to the LCD screen.
Flush mount switches that protrude only a few mm from the front panel offer an attractive design option and need to be available in a choice of different front construction materials to match the front panel. Designers may need products with lower cost, black plastic or metallised plastic lenses and bezels, or alternatively there could be a requirement for more a rugged anodised aluminium finish that can be coloured to match the front panel, whilst equipment for public use, or in hygienic applications might also need a more durable stainless steel switch construction.
Intuitive use is part of any modern design and this is improved by bright illumination and easy identification of switch functions with icons or text. Laser marking, etching or engraving of lenses allows coloured lenses for each function or ‘secret ‘till lit’ legends that are only visible when the function is available to be used by the operator. By incorporating the latest LED lighting technology designers can create dynamic multi-coloured lighting effects even on electromechanical switches that offer a satisfying tactile haptic response to the user. Products such as EAO’s flush mount Series 84 and Series 82 panel mount switches are ideal from modern HMI’s due to their low mounting depth, metal or plastic construction, bright vibrant illumination and wide range of marking options.
It’s an emergency – just Stop
Many modern HMI’s have most functions built in to the a touchscreen display, but for safety reasons where there is a danger to the operator of the equipment, or those around it, a clear fool proof and reliable means to bring about an ‘emergency stop’ is needed. The emergency stop function maybe fitted on the front panel of a machine or instrument, or it may need to be fitted into a hand held controller used by an operator near to the machine. Each application has its own special requirements so Emergency Stops have evolved to provide a vast range of products from compact 16mm mounted fully waterproof products suitable for hand held control boxes through to large 22mm mount metal body products resistant to operator abuse and harsh environments. In environments with low light levels or for night time operation the Emergency Stop may also need to be illuminated so it is easily located. EAO has a vast range of compact, rugged and illuminated Emergency Stops suitable for nearly every application.
Integration – ‘plug and play’ HMi’s
Equipment builders want to concentrate on their ‘core competencies’ – ensuring their products do what they say- in the best, most cost efficient manner. This is helped by a trend to a more integrated HMI, where added value products such as cables, connectors and front panels are supplied as a fully assembled and tested package. By working with an expert partner for Human Machine Interfaces such as EAO, the design, manufacture and supply of the complete HMI can be outsourced to a trusted partner.