IEC 61158-6-4:2014

IEC 61158-6-4:2007 defines the protocol provided to define the wire-representation of the service primitives defined in IEC 61158-5-4, and define the externally visible behaviour associated with their transfer. This standard specifies the protocol of the Type 4 fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498) and the OSI application layer structure (ISO/IEC 9545). This first edition and its companion parts of the IEC 61158-6 subseries cancel and replace IEC 61158-6:2003. This edition of this part constitutes a technical addition. This part and its Type 4 companion parts also cancel and replace IEC/PAS 62412, published in 2005. This edition of IEC 61158-6 includes the following significant changes from the previous edition: - deletion of the former Type 6 fieldbus for lack of market relevance; - addition of new types of fieldbuses; - partition of part 6 of the third edition into multiple parts numbered -6-2, -6-3,... This bilingual version (2014-12) corresponds to the monolingual English version, published in 2007-12.

IEC 61158-6-4:2019 provides common elements for basic time-critical and non-time-critical messaging communications between application programs in an automation environment and material specific to Type 2 fieldbus. The term ?time-critical? is used to represent the presence of a time-window, within which one or more specified actions are required to be completed with some defined level of certainty. Failure to complete specified actions within the time window risks failure of the applications requesting the actions, with attendant risk to equipment, plant and possibly human life. This International Standard specifies interactions between remote applications and defines the externally visible behavior provided by the Type 2 fieldbus application layer. The purpose of this document is to define the protocol provided to a) define the wire-representation of the service primitives defined in this document, and b) define the externally visible behavior associated with their transfer. This document specifies the protocol of the Type 2 fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application layer structure (ISO/IEC 9545). This third edition includes the following significant technical changes with respect to the previous edition: a) additional user parameters to services; b) additional services to support distributed objects; c) additional secure services.