IEC 61784-3-6:2010(E) specifies a safety communication layer (services and protocol) based on CPF 6 of IEC 61784-1, IEC 61784-2 and IEC 61158 Type 8. It identifies the principles for functional safety communications defined in IEC 61784-3 that are relevant for this safety communication layer. This second edition cancels and replaces the first edition published in 2007. This edition constitutes a technical revision. The main changes with respect to the previous edition are the updates in relation with changes in IEC 61784-3.