THREADX Certification

Express Logic’s THREADX RTOS has been used in safety-critical products within the fields of avionics, medical devices, transportation, and industrial control equipment. Developers facing IEC, FDA, or other regulatory approval requirements for safety-critical operation now have 3 solutions from Express Logic to make their job easier:

  • TUV Certification
  • UL Certification
  • Certification Pack

Each of these solutions offers benefits for developers of safety-critical systems:

TÜV Off-the-shelf Certification

TÜV Off-the-shelf Certification

THREADX has been certified by SGS-TÜV Saar for use in safety-critical systems, according to IEC-61508, IEC-62304, ISO 26262 and EN 50128. The certification confirms that THREADX can be used in the development of safety-related software for the highest safety integrity levels of IEC 61508, IEC 62304, ISO 26262 and EN 50128 for the Functional Safety of electrical, electronic, and programmable electronic safety-related systems. SGS-TÜV Saar, formed through a joint venture of Germany’s SGS-Group and TÜV Saarland, has become the leading accredited, independent company for testing, auditing, verifying and certifying embedded software for safety-related systems worldwide. The industrial safety standard IEC 61508, and all standards that are derived from it, including IEC 62304, ISO 26262 and EN 50128, are used to ensure the functional safety of electrical, electronic, and programmable electronic safety-related medical devices, process control systems, industrial machinery, automobiles and railway control systems.


SGS-TÜV Saar has evaluated the relevant parts of Express Logic’s modified waterfall development process for THREADX, with phase overlap and phase blending, to ensure that best development practices have been followed at these stages:

  • Requirements Management
  • Design
  • Implementation
  • Verification
  • Maintenance

SGS-TUV Saar, as part of the certification, has reviewed the extensive test suite for THREADX RTOS. The THREADX test suite, comprised of a large number of application simulations, effectively performs functional black box testing over the entire THREADX RTOS. The tests exercise 100 percent of the generic THREADX C code, which is validated by using code coverage analysis tools. Express Logic’s THREADX Safety Manual documents these quality assurance measures, which enable developers to use THREADX in safety-critical software development for even the most rigorous Safety Integrity Level (SIL), according to IEC 61508, IEC 62304, ISO 26262 or EN 50128 without further qualification.

UL Off-the-shelf Certification

THREADX® has been recognized by UL for compliance with UL 60730-1 Annex H, CSA E60730-1 Annex H, IEC 60730-1 Annex H, UL 60335-1 Annex R, IEC 60335-1 Annex R, and UL 1998 safety standards for software in programmable components. UL is a global, independent, safety-science company with more than a century of expertise innovating safety solutions, ranging from the public adoption of electricity to breakthroughs in sustainability, renewable energy, and nanotechnology.

CRUus Logo

THREADX is the first RTOS to achieve UL recognition to the standards UL 60730-1, CSA E60730-1, IEC 60730-1, UL 60335-1, and IEC 60335-1, commented Jason R. Smith, Staff Engineer of UL. We are excited that Express Logic now is able to apply the UL mark to its products, giving home appliance manufacturers confidence that they can use THREADX and be assured of its compliance with these important safety standards.

Along with IEC/UL 60730-1, which has requirements for “Controls Using Software” in its Annex H, the IEC 60335-1 standard describes the requirements for “Programmable Electronic Circuits” in its Annex R. IEC 60730 Annex H and IEC 60335-1 Annex R address the safety of MCU hardware and software used in appliances such as washing machines, dishwashers, dryers, refrigerators, freezers, and ovens. Building on the UL1998 foundation, additional requirements addressing the issues of software safety in programmable components for home appliances have now been added to the latest editions of the UL 60730/60335 standards. THREADX is the first to have satisfied those new requirements.

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