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61508
IEC 61508 is an international standard published by the International Electrotechnical Commission (IEC) consisting of methods on how to apply, design, deploy and maintain automatic protection systems called safety-related systems. It is titled ''Functional Safety of Electrical/Electronic/Programmable Electronic Safety-related Systems'' (E/E/PE, or E/E/PES). IEC 61508 is a basic functional safety standard applicable to all industries. It defines functional safety as: “part of the overall safety relating to the EUC (Equipment Under Control) and the EUC control system which depends on the correct functioning of the E/E/PE safety-related systems, other technology safety-related systems and external risk reduction facilities.” The fundamental concept is that any safety-related system must work correctly or fail in a predictable (safe) way. The standard has two fundamental principles: # An engineering process called the safety life cycle is defined based on best practices in order ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Safety
Functional safety is the part of the overall safety of a system or piece of equipment that depends on automatic protection operating correctly in response to its inputs or failure in a predictable manner (fail-safe). The automatic protection system should be designed to properly handle likely systematic errors, hardware failures and operational/environmental stress. Objective The objective of functional safety is freedom from unacceptable risk of physical injury or of damage to the health of people either directly or indirectly (through damage to property or to the environment) by the proper implementation of one or more automatic protection functions (often called safety functions). A safety system (often called a safety-related system) consists of one or more safety functions. Functional safety is intrinsically end-to-end in scope in that it has to treat the function of a component or subsystem as part of the function of the entire automatic protection function of any system. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO 26262
ISO 26262, titled "Road vehicles – Functional safety", is an international standard for functional safety of electrical and/or electronic systems that are installed in serial production road vehicles (excluding mopeds), defined by the International Organization for Standardization (ISO) in 2011, and revised in 2018. Overview of the Standard Functional safety features form an integral part of each automotive product development phase, ranging from the specification, to design, implementation, integration, verification, validation, and production release. The standard ISO 26262 is an adaptation of the Functional Safety standard IEC 61508 for Automotive Electric/Electronic Systems. ISO 26262 defines functional safety for automotive equipment applicable throughout the lifecycle of all automotive electronic and electrical safety-related systems. The first edition (ISO 26262:2011), published on 11 November 2011, was limited to electrical and/or electronic systems installed in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEC 61511
IEC standard 61511 is a technical standard which sets out practices in the engineering of systems that ensure the safety of an industrial process through the use of instrumentation. Such systems are referred to as ''Safety Instrumented Systems''. The title of the standard is "''Functional safety - Safety instrumented systems for the process industry sector''". Scope The process industry sector includes many types of manufacturing processes, such as refineries, petrochemical, chemical, pharmaceutical, pulp and paper, and power. The process sector standard does not cover nuclear power facilities or nuclear reactors. IEC 61511 covers the application of electrical, electronic and programmable electronic equipment. While IEC 61511 does apply to equipment using pneumatic or hydraulic systems to manipulate final elements, the standard does not cover the design and implementation of pneumatic or hydraulic logic solvers. This standard defines the functional safety requirements establi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FMEDA
Failure modes, effects, and diagnostic analysis (FMEDA) is a systematic analysis technique to obtain subsystem / device level failure rates, failure modes and diagnostic capability. The FMEDA technique considers: * All components of a design, * The functionality of each component, * The failure modes of each component, * The effect of each component failure mode on the product functionality, * The ability of any automatic diagnostics to detect the failure, * The design strength (de-rating, safety factors), * The impact of any latent fault tests, and * The operational profile (environmental stress factors). Given a component database calibrated with field failure data that is reasonably accurate, the method can predict device level failure rate per failure mode, useful life, automatic diagnostic effectiveness, and latent fault test effectiveness for a given application. The predictions have been shown to be more accurate than field warranty return analysis or even typical field fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spurious Trip Level
Spurious trip level (STL) is defined as a discrete level for specifying the spurious trip requirements of safety functions to be allocated to safety systems. An STL of 1 means that this safety function has the highest level of spurious trips. The higher the STL level the lower the number of spurious trips caused by the safety system. There is no limit to the number of spurious trip levels. Safety functions and systems are installed to protect people, the environment and for asset protection. A safety function should only activate when a dangerous situation occurs. A safety function that activates without the presence of a dangerous situation (e.g., due to an internal failure) causes economic loss. The spurious trip level concept represents the probability that safety function causes a spurious (unscheduled) trip. The STL is a metric that is used to specify the performance level of a safety function in terms of the spurious trips it potentially causes. Typical safety systems that ben ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEC 62061
IEC/EN 62061, ”Safety of machinery: Functional safety of electrical, electronic and programmable electronic control systems”, is the machinery specific implementation of IEC/EN 61508. It provides requirements that are applicable to the system level design of all types of machinery safety-related electrical control systems and also for the design of non-complex subsystems or devices. The risk assessment results in a risk reduction strategy which in turn, identifies the need for safety-related control functions. These functions must be documented and must include: * Functional requirements specification * Safety integrity requirements specification The functional requirements include details like frequency of operation, required response time, operating modes, duty cycles, operating environment, and fault reaction functions. The safety integrity requirements are expressed in levels called safety integrity level (SIL). Depending on the complexity of the system, some or all of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time-triggered System
Time-triggered architecture (abbreviated as TTA), also known as a time-triggered system, is a computer system that executes one or more sets of tasks according to a predetermined and set task schedule.Pont, M.J. (2001) "Patterns for Time-Triggered Embedded Systems", Addison-Wesley / ACM Press. . Implementation of a TT system will typically involve use of a single interrupt that is linked to the periodic overflow of a timer. This interrupt may drive a task scheduler (a restricted form of real-time operating system). The scheduler willin turnrelease the system tasks at predetermined points in time. History and development Because they have highly deterministic timing behavior, TT systems have been used for many years to develop safety-critical aerospace and related systems.Ward, N. J. (1991) "The static analysis of a safety-critical avionics control system", in Corbyn, D.E. and Bray, N. P. (Eds.) "Air Transport Safety: Proceedings of the Safety and Reliability Society Spring Conf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IEC Standards
The International Electrotechnical Commission (IEC; ) is an international standards organization that prepares and publishes international standards for all electrical, electronic and related technologies. IEC standards cover a vast range of technologies within electrotechnology. The numbers of older IEC standards were converted in 1997 by adding 60000; for example IEC 27 became IEC 60027. IEC standards often have multiple sub-part documents; only the main title for the standard is listed here. * IEC 60027 Letter symbols to be used in electrical technology * IEC 60028 International standard of resistance for copper * IEC 60034 Rotating electrical machines * IEC 60038 IEC Standard Voltages * IEC 60041 Field acceptance tests to determine the hydraulic performance of hydraulic turbines, storage pumps and pump-turbines * IEC 60044 Instrument transformers * IEC 60045 Steam turbines * IEC 60050 International Electrotechnical Vocabulary * IEC 60051 Direct acting indicating analo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modified Condition/Decision Coverage
Modified condition/decision coverage (MC/DC) is a code coverage criterion used in software testing. Overview MC/DC requires all of the below during testing: #Each entry and exit point is invoked #Each decision takes every possible outcome #Each condition in a decision takes every possible outcome #Each condition in a decision is shown to independently affect the outcome of the decision. Independence of a condition is shown by proving that only one condition changes at a time. MC/DC is used in avionics software development guidance DO-178B and DO-178C to ensure adequate testing of the most critical (Level A) software, which is defined as that software which could ''provide (or prevent failure of)'' continued safe flight and landing of an aircraft. It is also highly recommended for SIL 4 in part 3 Annex B of the basic safety publication and ASIL D in part 6 of automotive standard ISO 26262. Additionally, NASA requires 100% MC/DC coverage for any safety critical software componen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motor Industry Software Reliability Association
The Motor Industry Software Reliability Association (MISRA) is an organization that produces guidelines for the software developed for electronic components used in the automotive industry. It is a collaboration between numerous vehicle manufacturers, component suppliers and engineering consultancies. Aim The aim of this organization is to provide advice in questions of quality assurance mainly to the automotive industry for the creation and application of safe, reliable software within vehicles. The mission statement of MISRA is ''"To provide assistance to the automotive industry in the application and creation within vehicle systems of safe and reliable software"''. The safety requirements of the software used in control units of Automobiles is specific as compared to that of other industries and devices. MISRA creates, reviews and publishes (sells) standards, such as the MISRA C Coding Standard for the C programming language, first published in 1998. History MISRA was formed i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Standards
Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others. The presence of either a positive or negative electric charge produces an electric field. The motion of electric charges is an electric current and produces a magnetic field. In most applications, Coulomb's law determines the force acting on an electric charge. Electric potential is the work done to move an electric charge from one point to another within an electric field, typically measured in volts. Electricity plays a central role in many modern technologies, serving in electric power where electric current is used to energise equipment, and in electronics dealing with electrical c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DO-178C
DO-178C, Software Considerations in Airborne Systems and Equipment Certification is the primary document by which the certification authorities such as Federal Aviation Administration, FAA, European Aviation Safety Agency, EASA and Transport Canada approve all commercial software-based aerospace systems. The document is published by RTCA, Incorporated, in a joint effort with EUROCAE, EUROC and replaces DO-178B. The new document is called DO-178C/ED-12C and was completed in November 2011 and approved by the RTCA in December 2011. It became available for sale and use in January 2012. Except for Federal_Aviation_Regulations#Organization, FAR 33/Joint Aviation Requirements, JAR E, the Federal Aviation Regulations do not directly reference software airworthiness. On 19 Jul 2013, the FAA approved AC 20-115, AC 20-115C, designating DO-178C a recognized "acceptable means, but not the only means, for showing compliance with the applicable FAR airworthiness regulations for the software asp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
