IEC 61158-5-8:2007
Industrial communication networks - Fieldbus specifications - Part 5-8: Application layer service definition - Type 8 elements

Standard No.

IEC 61158-5-8:2007

Release Date

2007

Published By

International Electrotechnical Commission (IEC)

Latest

IEC 61158-5-8:2007

Replace

IEC 65C/475/FDIS:2007 IEC 61158-5:2003

Scope

1.1 Overview The fieldbus application layer (FAL) provides user programs with a means to access the fieldbus communication environment. In this respect, the FAL can be viewed as a “window between corresponding application programs.” This standard 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 8 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. 1.2 Specifications The principal objective of this standard is to specify the characteristics of conceptual application layer services suitable for time-critical communications, and thus supplement the OSI Basic Reference Model in guiding the development of application layer protocols for timecritical communications. A secondary objective is to provide migration paths from previously-existing industrial communications protocols. It is this latter objective which gives rise to the diversity of services standardized as the various Types of IEC 61158, and the corresponding protocols standardized in subparts of IEC 61158-6. This specification may be used as the basis for formal application programming interfaces. Nevertheless, it is not a formal programming interface, and any such interface will need to address implementation issues not covered by this specification, including a) the sizes and octet ordering of various multi-octet service parameters, and b) the correlation of paired request and confirm, or indication and response, primitives. 1.3 Conformance This standard does not specify individual implementations or products, nor does it constrain the implementations of application layer entities within industrial automation systems. There is no conformance of equipment to this application layer service definition standard. Instead, conformance is achieved through implementation of conforming application layer protocols that fulfill the Type 8 application layer services as defined in this standard.

IEC 61158-5-8:2007 Referenced Document

• IEC 60559 Binary floating-point arithmetic for microprocessor systems
• ISO/IEC 10731 Information technology - Open Systems Interconnection - Basic Reference Model - Conventions for the definition of OSI services
• ISO/IEC 646 Information technology; ISO 7-bit coded character set for information interchange
• ISO/IEC 7498-1 Information technology — Open Systems Interconnection — Basic Reference Model: The Basic Model
• ISO/IEC 7498-3 Information technology - Open Systems Interconnection - Basic reference model: Naming and addressing
• ISO/IEC 8822 Amendment 2 - Information technology -- Open Systems Interconnection -- Presentation service definition - Nested connections functional unit
• ISO/IEC 8824 Information technology; open systems interconnection; specification of abstract syntax notation one (ASN.1)
• ISO/IEC 9545 Information technology - Open Systems Interconnection - Application layer structure

IEC 61158-5-8:2007 history

• 2007 IEC 61158-5-8:2007 Industrial communication networks - Fieldbus specifications - Part 5-8: Application layer service definition - Type 8 elements

IEC 61158-5-8:2007 Industrial communication networks - Fieldbus specifications - Part 5-8: Application layer service definition - Type 8 elements has been changed from IEC 61158-5:2003 Digital data communication for measurement and control - Fieldbus for use in industrial control systems - Part 5: Application layer service definition.