TrackLink 4 - The Next-Generation in SIL 2-Certified Track-to-Train Communication

With TrackLink® 4, we introduce the next generation of our proven track-to-train communication technology.

Developed by our rail centre of excellence, Sella Controls, TrackLink 4 combines onboard readers with passively powered trackside beacons to provide highly reliable, location-based communication between train and infrastructure. Introduced to the rail industry at InnoTrans 2026, the platform supports precise train positioning and enables a range of operational and safety-related applications while bringing greater openness and connectivity to the digital railway.

Building on Proven Technology

TrackLink technology has already been deployed in railway applications around the world. With TrackLink 4, we have evolved this proven technology into a new-generation platform designed to meet the changing requirements of modern rail systems.

Compared with its predecessor, TrackLink 4 introduces:

• Optional Ethernet connectivity as an alternative to the serial interface
• Multiple protocol integration
• Extended safety I/O
• A doubled data payload, from 6 to 12 bytes
• Secure communication at speeds exceeding 200 km/h

The platform is designed to operate in demanding railway environments, with the introduction of an IP68 rated beacon, as well as an extended operating temperature range of -25°C to +65°C,. To support robust data transmission, TrackLink 4 utilizes dual-tag configuration.

TrackLink 4 is being developed in accordance with IEC 62443 security principles and aligned with the intent of the Cyber Resilience Act, incorporating secure design, controlled access, and secure communications to protect against unauthorised access and cyber threats.

Precise Location-Based Communication

TrackLink 4 combines an onboard reader with passively powered trackside beacons to deliver precise, location-based communication between train and infrastructure.

As a train passes a beacon, TrackLink 4 enables the exchange of location-specific information between vehicle and infrastructure. This highly reliable communication can be used to support a range of operational and safety functions based on the train's exact position.

The passively powered beacon design helps simplify infrastructure deployment while delivering dependable communication between rolling stock and trackside infrastructure. Beacon variants are available for both mainline and light rail/metro environments.

1 Onboard Reader

2 Beacon

Watch: TrackLink 4 Explained 

In this video, Rob Nield explains how TrackLink 4 combines precise train positioning with reliable track-to-train communication and highlights the key capabilities of the platform.  

Applications Across the Railway Network

TrackLink 4 supports a variety of operational and safety applications, including:

• Automatic Selective Door Opening

• Correct Side Door Enabling

• Automatic Power Change Over
• Overspeed prevention
• Radio Change Over

By providing highly reliable, location-based communication between train and infrastructure, the platform helps operators implement these functions safely and efficiently.

Benefits for Rolling Stock Manufacturers and Operators

At InnoTrans 2026, we showcased TrackLink 4 as part of our certified onboard safety solutions for vehicle control, modernization, and lifecycle management.

Featuring precise train positioning and reliable vehicle-to-infrastructure communication, the platform delivers key benefits for operators and rolling stock manufacturers:

• Safe and Compliant Train Operation
  Reliable location-based communication supports safe and compliant train operation.

• Easier Modernization
  Optional Ethernet connectivity, multiple protocol integration, and extended safety I/O help simplify integration into modern rail architectures, with cyber security considered from the outset in line with IEC 62443 principles.

• Improved Lifecycle Efficiency
  TrackLink 4 supports more efficient lifecycle management and helps operators maintain safe and reliable railway operations over the long term.

See the Complete Solution in Action

This animation demonstrates how onboard readers, passively powered trackside beacons, and onboard systems work together within the TrackLink 4 platform to deliver reliable track-to-train communication.  

Supporting the Digital Railway

As Chris Elliott, Head of Global Account Management Rail, explains:

“TrackLink 4 represents the next evolution of our proven track-to-train communication technology. Developed through the combined rail expertise of HIMA and Sella Controls, it brings proven safety together with the openness and connectivity required for the digital railway.”

By combining proven safety, reliable communication, and modern connectivity, TrackLink 4 provides a future-ready platform for railway operators and rolling stock manufacturers.

Download the TrackLink® 4 Fact Sheet

Want to learn more about the technology behind TrackLink 4?

Download the fact sheet for a detailed overview of:

• Optional Ethernet connectivity
• Multiple protocol integration
• Extended safety I/O
• Cybersecurity by design
• Dual-tag beacon configuration
• Operating environment and protection ratings
• Key applications and technical capabilities