SIL-compliant speed signal doubling for safety-critical applications

Precise, real-time speed data for Modern Rail Systems

Modern railways are rapidly evolving. With advanced train control systems such as CBTC (Computer-Based Train Control), PTC (Positive Train Control), ETCS (European Train Control System) and ATO (Automatic Train Operation) now essential to safety and efficiency, train control system integrators face a shared challenge: All these systems depend on precise, real-time speed data.

Traditionally, integrating these new systems means adding additional speed sensors on the train’s bogie or if space is limited, replacing the speed sensors with multichannel versions. Both variants are a costly, time-intensive process involving mechanical modification, new wiring, and lengthy vehicle downtime.

But what if you could provide reliable speed data to multiple systems while keeping retrofit costs and installation complexity to a minimum?

Created to reduce cost and complexity in Advanced Train Control Systems

P16890 offers a unique solution that eliminates these issues.

Instead of adding hardware to the bogie, the compact, DIN rail–mounted P16890 is installed within a control cabinet. It decouples an existing encoder’s signal without interaction in accordance with SIL 4 (EN 50129), evaluating the direction of travel (DoT) and providing galvanically isolated outputs to other systems such as CBTC, PTC, ETCS, ATO, Collision Warning Systems or Passenger Information Systems. Optionally, the output frequency can be reduced relative to the input at a ratio of 2:1 or 4:1, while maintaining the 90° phase reference between the two channels of the speed sensor – allowing the direction of rotation information to be evaluated.

Compared to conventional solutions, P16890 stands out thanks to an easy installation, a reduction in system complexity, and significant cost savings.