IEC 61784-3-12:2010+A1:2019 specifies a safety communication layer (services and protocol) based on CPF 12 of IEC 61784-2 and IEC 61158 Type 12. It identifies the principles for functional safety communications defined in IEC 61784-3 that are relevant for this safety communication layer. This bilingual version (2012-02) corresponds to the monolingual English version, published in 2010-06. This consolidated version consists of the first edition (2010) and its amendment 1 (2019). Therefore, no need to order amendments in addition to this publication.