What Is a Safety Critical RTOS?
A Safety Critical RTOS is a Real Time Operating System that has been designed to comply with a specific safety critical design standard. Compliance to these standards guarantees performance and creates a robust and deterministic RTOS, allowing the safety critical RTOS to be used widely in industries where failure could result in harm to people – eg medical (IEC 62304), automotive(ISO 26262),industrial applications(IEC 61508) and aerospace (DO-178C).
Safety Design Standards
The Safety design standards exist to ensure a consistent, high level of confidence in systems that implement safety critical functionality across different vertical markets. These design standards typically cover all aspects of system, hardware, software, design and verification, and also include integration and usage issues. Different market sectors have created their own sector specific standards. For many market sectors the underlying principles of software design and verification are similar; however the domain specific standards include processes and procedures for managing the unique system level risks present within each sector.
These safety requirements are dependant on industry, but typically are based around the standard IEC 61508. IEC 61508 is a generic Industrial safety standard supporting the design, development and operation of electrical/electronic/programmable electronic systems. for more information about functional safety standards, please see our IEC 61508 page.
The safety critical RTOS is a key component of most high integrity software architectures, with many corporations choosing to select a single safe RTOS across their entire organization.
Principal Engineer at WHIS
14th October 2022
How is a Safety Critical RTOS
Different From a Commercial RTOS?
The inclusion of the safety requirements creates a significant difference between a commercial grade RTOS and an RTOS designed for Functional Safety use. As the functional requirements are the same, usually the operation and API are similar but underneath the API the design and code will have been completely redesigned for safety. The adherence to the relevant safety standard means that there is much smaller chance of malfunction or delay when executing tasks.
Advantages of a Safety Critical RTOS
With the increasing growth of regulation, and certification bodies accepting systems made up from pre-certified blocks, there is an increasing demand for pre-certified software components. The following benefits are expanded in this handy guide: 8 Reasons to Use a Safety RTOS
- Greater Determinism & Robustness
- Spatial Separation of Tasks
- Designed to your Specific Compiler and Processor
- Quality Assurance