IEC 61784-3-2:2010(E) specifies a safety communication layer (services and protocol) based on CPF 2 of IEC 61784-1, IEC 61784-2 and IEC 61158 Type 2. 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: - updates in relation with changes in IEC 61784-3; - addition or modification of the following subclauses to support the extended format: 6.3.2.1, 6.3.3.4, 6.3.11, 6.6.7.5, 6.8.5.13, 6.8.