IEC 61784-3-12:2010 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.