IEC 61158-1:2014 specifies the generic concept of fieldbuses. It also presents an overview and guidance for the IEC 61158 series by: - explaining the structure and content of the IEC 61158 series; - relating the structure of the IEC 61158 series to the ISO/IEC 7498-1 OSI Basic Reference Model; - showing the logical structure of the IEC 61784 series; - showing how to use parts of the IEC 61158 series in combination with the IEC 61784 series; - providing explanations of some aspects of the IEC 61158 series that are common to the type specific parts of the IEC 61158-5 including the application layer service description concepts and the generic fieldbus data types. This first edition cancels and replaces the third edition of IEC/TR 61158-1 published in 2010 and constitutes a technical revision. It includes the following changes: - updates of the references to and information about the IEC 61158 series, IEC 61784-1, IEC 61784-3, IEC 61784-5 series and IEC 61918 throughout the document; - new Type 23 for profile family 8; - new Type 24 and the related profile family CPF 19; - new Subclause 7.7 Communication profiles for wireless communication networks; - new Clause 11 Fieldbus system requirements; - new Annex B Media selection for fieldbus systems.