EN ISO 25119-4:2023

This document sets out general principles for the design and development of safety-related parts of control systems (SRP/CS) on tractors used in agriculture and forestry and on self-propelled ride-on machines and mounted, semi-mounted and trailed machines used in agriculture. It can also be applied to mobile municipal equipment (e.g. street-sweeping machines). This document is not applicable to: - aircraft and air-cushion vehicles used in agriculture; - lawn and garden equipment. This document specifies the characteristics and categories required of SRP/CS for carrying out their safety-related functions. It does not identify performance levels for specific applications. NOTE 1 Machine specific type-C standards can specify performance levels (AgPL) for safety-related functions in machines within their scope. Otherwise, the specification of AgPL is the responsibility of the manufacturer. This document is applicable to the safety-related parts of electrical/electronic/programmable electronic systems (E/E/PES), as these relate to mechatronic systems. It covers the possible hazards caused by malfunctioning behaviour of E/E/PES safety-related systems, including interaction of these systems. It does not address hazards related to electric shock, fire, smoke, heat, radiation, toxicity, flammability, reactivity, corrosion, release of energy, and similar hazards, unless directly caused by malfunctioning behaviour of E/E/PES safety-related systems. It also covers malfunctioning behaviour of E/E/PES safety-related systems involved in protective measures, safeguards, or safety-related functions in response to non-E/E/PES hazards. Examples included within the scope of this document: - SRP/CS limiting current flow in electric hybrids to prevent insulation failure/shock hazards; - electromagnetic interference with the SRP/CS; - SRP/CS designed to prevent fire. Examples not included in the scope of this document: - insulation failure due to friction that leads to electric shock hazards; - nominal electromagnetic radiation impacting nearby machine control systems; - corrosion causing electric cables to overheat. This document is not applicable to non-E/E/PES systems (e.g. hydraulic, mechanic or pneumatic). NOTE 2 See also ISO 12100 for design principles related to the safety of machinery. This document is not applicable to safety related parts of control systems manufactured before the date of its publication.