IEC 61784-3-18:2011+A1:2016 specifies a safety communication layer (services and protocol) based on CPF 18 of IEC 61784-2 and IEC 61158 Type 22. It identifies the principles for functional safety communications defined in IEC 61784-3 that are relevant for this safety communication layer. This consolidated version consists of the first edition (2011) and its amendment 1 (2016). Therefore, no need to order amendment in addition to this publication.