Functional safety is essential for the protection of people. What has been safety standard in the railway sector for more than 10 years, is now state of the art for all industries: the safe display and data entry on a TFT screen up to Safety Integrity Level 3.
The patented Trust functions included inside the D-ViewTrust terminals ensure that safety-relevant display contents are represented in a functionally safe manner, without interfering with the customer application. In contrast to conventional methods, the Trust technologies offer more safety for the display and the operation in safety-relevant areas of a TFT, representing reliably the determined values. The user can immediately recognise when deviations occur.
With IconTrust, type and layout of the representation can be modified flexibly and easily in safety- relevant areas. In case the application is just being developed or, if it is being adapted to a new requirement, then safety can be reverified without a time-consuming qualification process. The safety concept is modular and can be retrofitted to any existing HMI system.
Our D-ViewTrust Terminal is equipped with a DEUTA HMI Safety Package.
The HMI Safety Package is assessed according to the basic safety standard for functional safety IEC61508 meeting the requirement SIL3/PL-e and for the safe data entry SIL2/PL-d.
The safety technologies of the D-ViewTrust Terminals supervise all types of input variables which are represented as symbols, pointer instruments or bar graphs, letters, text or even as a play of colours. If required, it is possible to allow different screen representations for one and same value of the input variable (equivalent representations).
As part of the HMI Safety Package, IconTrust supervises dedicated areas on the TFT panel and differentiates between safety-relevant and non safety-relevant information up to PL-e or SIL 3: IconTrust supervises dynamic and static areas on the HMI panel, recognises the validity of displayed information, confirms the receipt of the current process data via a safe connection and compares the displayed process value with the input process value.
The SelectTrust technology enables a safe touch input with the Performance Level PL-d or SIL 2. The input areas shown on the display are safely supervised. With actuation, a respective safe data protocol is generated – completely independently and in parallel to the processing of non-safe input data by the HMI.