FEATURE |
HMI design more
than
pretty pictures Human machine interface (HMI) design. When boring reigns supreme...
I
n order to ensure successful implementation, effective HMI design should start with some proper planning. Just making a HMI look cool is not always the best answer. HMIs are present in a great deal of applications, leading to multiple lessons to consider when starting a new design project. More often than not, programmers overlook what they could have learned from past designs (and even mistakes) until it’s too late. It is imperative that accidents from the past are used to ensure success in the future. Arming yourself with simple rules from lessons learnt to communicate to operations is extremely important to the success of your project. Remember the need of your audience The primary HMI design concerns are not for Colour selection engineering, maintenance or management, It’s for the main line of control; the operator. Evaluate Keep it simple and boring, in this case boring means effective. It is all about being what would or should be showing to operations. able to show the anomaly in the process. Background colours should be kept Not that other groups should be disregarded but monotone using grey scale if possible. Primary colours such as red, green, or blue they should be secondary. Operations will spend should not be used as a background colour. Black and white show great contrast, most of their time watching the same things over and over again. Issues such as eyestrain are a large part to design consideration. Screen layout Alerts to changes should stand out, process A third layer may be used with additional holdups should be able to be evaluated piping detail and process representation Screen layout is important for quickly and all systems that are the same but should be done sparingly. Device good HMI interaction. Screens should look that way. Control functions information is ideal and accessible from should have set layers, as too many should be standard and the same across this third level. Remember operators drill downs will lead to distraction. the board. The secondary group will will do this every day and know the Good design does not have a lot of probably want to see a different layer of the equipment. What one thinks is important process detail, but more red light, system. For management it will be high when doing the initial design will change green light indication for the areas level overviews and production graphs with exposure. Single quick navigation that are built underneath. From the & data. For maintenance, help points should be used when possible. Menu overview within one tap the secondary should exist to navigate into the PLC or bars and active alarm banners help keep main layer of detail should be shown DCS to make troubleshooting easier. the process within one tap. Screen popincluding device control. ups need to be kept to a minimum.
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