A number of interrelated—and sometimes overlapping—safety standards have been developed as a result of the European Commission’s enactment of the wide-ranging Machinery Directive. Different safety standards apply to manufacturers of machines and electronic control system and drives. Knowing these are important because of increasing efforts to integrate safety and motion in machines and on the plant floor.

　　For machines builders

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, EN 954-1 (European), ISO 13849-1 (International Standards Organization), and IEC 62061 (International Electrotechnical Commission) standards currently apply with one important change. EN 954-1 (“Safety of machineryCONTROL ENGINEERING China版权所有, Safety related parts of control systems”) is in a transitional period that expires as of Nov. 2009CONTROL ENGINEERING China版权所有, when ISO 13849-1 (with the same title) becomes the applicable standard. EN 954-1 has served as a sort of “gold standard” but its simpler deterministic approach to assessment of risk and safety system reliability needed updating to newer probabilistic methods and technology advancements.
　　For electronic control system and drives manufacturers, applicable standards include IEC 61508 (“Functional safety of electrical/ electronic/ programmable electronic safety-related systems”) and IEC 61800-5-2 (“Adjustable speed electrical power drive systems”). These newer standards cover the concepts of functional safety discussed in the main article, “Integrated Safety and Motion.” They define methods to assess probability of dangerous failure in machine and control systems through calculation tools such as safety integrity level (SIL) and performance level (PL).
　　ISO 13849-1 builds on EN 954-1

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, specifying system reliability in one of five PLswww.cechina.cn, based on a “hardware-oriented structureCONTROL ENGINEERING China版权所有,” calculated mean time to dangerous failure

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, and diagnostic coverage of the safety function. This standard applies beyond electric/electronic systems to include hydraulic and pneumatic equipment.
　　IEC 61508 was the first safety standard to address failure in a p