LabVIEW SIL Certification

Issue Details

What Level of SIL (safety integrity level) certification does LabVIEW have?

Solution

LabVIEW is not certified by any standard as it is a programming language like Visual Basic, C++ and PASCAL. LabVIEW is simply a tool to be used in a full application. As such, it is the application created by the programming language that must be certified.

Additional Information

Safety Integrated System: Functional Safety is freedom from unacceptable risk of physical injury or of damage to the health of people, either directly or indirectly as a result of damage to property or to the environment.

Functional safety is part of the overall safety that depends on a system or equipment operating correctly in response to its inputs. For example, an over-temperature protection device, using a thermal sensor in the windings of an electric motor to de-energise the motor before they can overheat, is an instance of functional safety. Providing specialized insulation to withstand high temperatures is not an instance of functional safety (although it is still an instance of safety and could protect against exactly the same hazard).

Generally, the significant hazards for equipment and any associated control system have to be identified by the specifier or developer via a hazard analysis. The analysis determines whether functional safety is necessary to ensure adequate protection against each significant hazard. If so, then it has to be taken into account in an appropriate manner in the design. Functional safety is just one method of dealing with hazards, and other means for their elimination or reduction, such as inherent safety through design, are of primary importance.

The term safety-related is used to describe systems that are required to perform a specific function or functions to ensure risks are kept at an accepted level. Such functions are, by definition, safety functions. Two types of requirements are necessary to achieve functional safety: __safety function requirements (what the function does) and __safety integrity requirements (the likelihood of a safety function being performed satisfactorily).

The safety function requirements are derived from the hazard analysis and the safety integrity requirements are derived from a risk assessment. The higher the level of safety integrity, the lower the likelihood of dangerous failure.

Any system, implemented in any technology, which carries out safety functions is a safety-related system. The safety-related system may be separate from any equipment control system or may be included within it. Higher levels of safety integrity necessitate greater rigour in the engineering of the safety-related system.

Safety Integrity Levels: IEC 61508 specifies 4 levels of safety performance for a safety function. These are called safety integrity levels. Safety integrity level 1 (SIL1) is the lowest level of safety integrity and safety integrity level 4 (SIL4) is the highest level. The standard details the requirements necessary to achieve each safety integrity level. These requirements are more rigorous at higher levels of safety integrity in order to achieve the required lower likelihood of dangerous failure.