scope:

IEC 61800-5-3:2021, which is a product standard, specifies requirements and makes recommendations for the design and development, integration and validation of safety-related encoder (Encoder(SR)) in terms of their functional safety considerations, electrical safety and environmental conditions. It applies to Encoder(SR), being sensors as part of a PDS(SR). This document can also be referred to and used for Encoder(SR) in any other safety-related application, for example safety-related position monitoring. This document is applicable where functional safety of an encoder is claimed and the Encoder(SR) is operating mainly in the high demand or continuous mode. The requirements of IEC 61800-5-2:2016 for PDS(SR) apply to Encoder(SR) as applicable. This document includes additional or different requirements for Encoder(SR). It sets out safety-related considerations of Encoder(SR) in terms of the framework of IEC 61508 (all parts), and introduces requirements for Encoder(SR) as subsystems of a safety-related system. It is intended to facilitate the realisation of the electrical/electronic/programmable electronic (E/E/PE) and mechanical parts of an Encoder(SR) in relation to the safety performance of safety sub-function(s) of an Encoder(SR).