Description

CSA RaSTA Protocol Stack Software Library

The CSA RaSTA Protocol Stack Software Library provides the next generation of safe and reliable communication for EULYNX‑compliant railway systems. It implements the RaSTA protocol according to DIN VDE V 0831-200 and was developed according to EN 50716 to achieve SIL4 compliance. The new Version 2 forms the foundation for fast, highly available and safe data exchange between interlockings and field elements. RaSTA is the official Safe Communication Protocol (SCP) of EULYNX and is required for EULYNX‑compatible interlockings and object controllers.

The stack is based on the proven RaSTA implementation described on the (https://www.rasta-stack.ch/), offering modular design, and easy integration into embedded platforms.

The new release from CSA extends the stack with significant improvements in scalability, throughput, memory efficiency and configuration flexibility, making it suitable for next‑generation object controllers and advanced signalling networks.

Key Benefits

New in CSA RaSTA Protocol Stack Software Library V2.0.x

• Support for up to 20 simultaneous connections
• Up to 4 redundant transport channels per connection
• Per‑connection parameterization (timeouts, message sizes, buffer lengths, etc.)
• Memory optimization through configurable buffer length and message size
• Transfer of up to 32 application messages in a single RaSTA data message
• Significantly reduced execution time, achieved through optimized MD4 algorithm and other performance optimizations
• Possibility to use separate memory areas for SIL4 and Basic Integrity software components
• Changes assessed by TüV to ensure SIL4 approval

Core RaSTA Benefits (based on protocol specification & stack properties)

• Implements the RaSTA protocol according to DIN VDE V 0831-200
• SIL4 compliance according to EN 50716
• Developed and documented according to EN 50126-1:2017, EN 50126-2:2017, EN 50129:2018 and EN 50159:2010
• Fast, highly available and safe communication for railway signaling applications in the EULYNX environment
• Modular architecture with Safety and Retransmission- and Redundancy Layer allows usage of black channel principle
• Optimized for embedded hardware and suitable for various 32- or 64-Bit platforms
• Designed to run on little- and big-endian systems
• Required for EULYNX Object Controllers and PDI/SCP communication workflows

Product Documents

• Official website: https://www.rasta-stack.ch/

EULYNX compliance

• Baseline release: EULYNX BL4R1, BL4R2, BL4R3, BL4R4
• Interface types: SCI