What is BS EN 61158-6-4 - Application layer protocol specification - Type 4 elements about?
BS EN 61158-6-4 is part of the BS EN IEC 61158 series that has been created to facilitate the interconnection of automation system components. 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.”
BS EN 61158-6-4 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 4 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.
BS EN 61158-6-4 defines in an abstract way the externally visible behaviour provided by the Type 4 Fieldbus application layer in terms of:
- The formal abstract syntax defining the application layer protocol data units conveyed between communicating application entities
- The transfer syntax defining encoding rules that are applied to the application layer protocol data units
- The application context state machine defining the application service behavior visible between communicating application entities
- The application relationship state machines defining the communication behavior visible
- between communicating application entities
BS EN 61158-6-4 defines the protocol provided to:
- Define the wire-representation of the service primitives defined in IEC 61158-5-4
- Define the externally visible behavior associated with their transfer
BS EN 61158-6-4 specifies the protocol of the Type 4 fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application layer structure (ISO/IEC 9545).
Who is BS EN 61158-6-4 - Application layer protocol specification - Type 4 elements for?
BS EN 61158-6-4 on application layer protocol specification - type 4 elements is useful for:
- The IT (Information Technology) industry / Software programmers
- Internet engineering task forces
- Internet service providers
- Telecommunication companies
- The automation industry
- Networking sectors
Why should you use BS EN 61158-6-4 - Application layer protocol specification - Type 4 elements?
BS EN 61158-6-4 was produced to facilitate the interconnection of automation system components. BS EN 61158-6-4 is related to other standards in the set as defined by the “three-layer” fieldbus reference model described in IEC 61158-1. The application protocol provides the application service by making use of the services available from the data link or other immediately lower layer. BS EN 61158-6-4 provide a set of rules for communication expressed in terms of the procedures to be
carried out by peer application entities (AEs) at the time of communication. These rules for communication are intended to provide a sound basis for development in order to serve a variety of purposes:
- As a guide for implementors and designers
- For use in the testing and procurement of equipment
- As part of an agreement for the admittance of systems into the open systems environment
- As a refinement to the understanding of time-critical communications within OSI
BS EN 61158-6-4 is concerned, in particular, with the communication and interworking of sensors,
effectors and other automation devices. Use BS EN 61158-6-4 with other standards positioned within the OSI or fieldbus reference models, otherwise incompatible systems may work together in any combination. BS EN 61158-6-4 specifies the syntax and behaviour of the application layer protocol that conveys the application layer services defined in BS EN 61158-6-4. This latter objective gives rise to the diversity of protocols standardized in IEC 61158-6. Using BS EN 61158-6-4 guidelines, you can facilitate communication between applications and accelerate productivity.
