- November 22, 2019
November 22, 2019 - A collaboration between DEUTA-WERKE and ABB is on track to introduce their Safe HMI equipped with PROFINET/PROFIsafe fieldbus for standard and safety communication
The safe-touch human-machine-interface (Safe HMI) up to SIL 3 (IEC 61508) for use in trains will support PROFINET/PROFIsafe industrial communication.
Under development by DEUTA-WERKE in collaboration with ABB, the Safe HMI displays either the train’s speed or the status of various safety zones. Fail-safe selections through user touch events and fail-safe graphical objects, like train speed or selected operating modes, can be exchanged between the Safe HMI and the ABB AC500-S safety PLC.
DEUTA-WERKE is a designer and manufacturer of systems, solutions and functional safety components for railway applications. The company’s continuous pursuit of the safety standards results in developing the Safe HMI as a safer way to visualize train speed, select operating modes and status of safety zones up to SIL3.
DEUTA-WERKE uses its IconTrust and SelectTrust technologies to develop Safe HMIs for train applications. For example, IconTrust technology simultaneously and independently monitors the safety-critical areas on the HMI screen. Should there be a deviation, it triggers a corresponding safety-oriented response. This can be sent through PROFINET/PROFIsafe to the AC500-S safety PLC for a more controllable safety reaction.
SelectTrust technology enables fail-safe selection on the Safe HMI using its touch screen commands. The selected value can be sent through PROFINET/PROFIsafe to the AC500-S safety PLC for further safety logic processing such as safely changing the operating mode of the application or changing safety process parameters.
Using SelectTrust technology on Safe HMIs can replace several hard-wired control elements on mechanical control panels.
With SIL3 Safe HMI versions, whenever a driver operates a touchscreen, two touch layers, situated one behind the other, are activated, feeding a comparative signal to a safety unit on the Safe HMI. The safety unit evaluates the touch event and translates it into a safety value, which is safely transferred to ABB’s safety PLC using PROFINET/PROFIsafe communication.
By transferring the PROFINET/PROFIsafe values to ABB’s safety CPU, the state of selection can be saved using the AC500-S safety CPU’s flash memory, ensuring that all events have persistent status. The flexibility of Structured Text and the ability to implement complex logic to handle and store all these selection states on the Safe HMI, are critical to the solution’s success. Furthermore, the ability to distribute Safe HMI information to more than one controller using not only PROFINET/PROFIsafe IO Controller but also PROFINET/PROFIsafe IO Device functionality is critical to the selection.
In the future, it is hoped that the Safe HMI will be adapted for industrial applications. Safe HMI offers a digital replacement for pressing a mechanical safety control button. Safe HMI enables the removal of various mechanical control elements within operator control rooms without compromising on functional safety.