TouchNetix acted as the principal engineering partner, helping to define, design and supply touch technology for the series of 15.6, 18.5 and 21.5-in. HMI systems. The company's brief was to help bring the advantages of full multi-touch performance to the Simatic HMI units while maintaining the robustness of the resistive touch technology used in previous designs.
The technology developed by TouchNetix, using a combination of innovative sensor designs and manufacturing processes, is coupled with a custom driver board and firmware to enable a choice of digitiser or mouse input modes. The overall system offers reliable touch response even in high electromagnetic interference (EMI) conditions, where water is present, and when the application necessitates that the user wears gloves.
"We needed to move beyond the existing state-of-the-art capacitive touch technology to meet our requirements and our timescales," said Silvio Rasek, Product Manager, Siemens Industrial Automation Division. "We engaged with TouchNetix because their track record of using existing technologies in innovative new ways allowed us to meet our performance requirements with the lowest possible risk.”
TouchNetix delivers the most advanced capacitive multi-touch performance through its expertise in electronics, sensor design, materials science and manufacturing technologies. The company's deployment tools and performance modelling techniques simplify the design-in process and ensure that projects are completed on-time and according to the specification.
Outlining the procedure that it brought to this design exercise, TouchNetix observes that a high percentage of the world's population now expects the “iPhone or iPad user experience” when they use a mission-critical industrial PC or a life-critical medical system. Manufacturers of these systems which have traditionally used resistive touchscreens have been looking hard at how to build a high performance, 100% reliable user interface based on already-commoditised consumer electronics components. This has turned out to be harder than it might appear.
The company believes that using the best available capacitive touchscreen driver ICs it is possible to build a highly optimised capacitive