This European Standard provides safety requirements and guidance on the principles for the design (see [clause] 3.11 of EN 292-1 : 1991) of safety-related parts of control systems.For these it specifies categories and describes the characteristics of their safety functions. This includes programmable systems for all machinery and for related protective devices. It applies to all safety-related parts of cotrol systems, regardless of the type of energy used, e.g. electrical, hydraulic, pneumatic, mechanical. It does not specify which safety functions and which categories shall be used in a particular case. It applies to all machinery applications for professional and non-professional use. Also, where appropriate, this standard can be applied to the safety-related parts of control systems used in other technical applications.