IEC 61158-3-21 pdf download – Industrial communication networks – Fieldbus specifications – Part 3 21: Data-link layer service definition – Type 21 elements

IEC 61158-3-21 pdf download – Industrial communication networks – Fieldbus specifications – Part 3 21: Data-link layer service definition – Type 21 elements
Scope1.1overview
This part of IEC 61158 provides the common elements for basic time-critical messagingcommunications between devices in an automation environment. The term “time-criticaiinthis context means the prioritized full-duplex collision-free time-deterministic communication,of which one or more specified actions are required to be completed with some defined levelof certainty.Failure to complete specified actions within the required time risks the failure ofthe applications requesting the actions, with attendant risk to equipment,plant, and possiblyhuman life.
This standard defines in an abstract way the externally visible service provided by theType 21 data-link layer in terms of:
a) the primitive actions and events of the service;
b) the parameters associated with each primitive action and event,and the form that theytake; and
c) the interrelationships between these actions and events,and their valid sequences.The purpose of this standard is to define the services provided to:
. The Type 21 application layer at the boundary between the application and DLLs of the
fieldbus reference model;
Systems management at the boundary between the DLL and the systems management ofthe fieldbus reference model.
1.2Specifications
The principal objective of this standard is to specify the characteristics of conceptual DLLservices suitable for time-critical communications, and to supplement the OSI BasicReference Model in guiding the development of data link protocols for time-criticalcommunications. A secondary objective is to provide migration paths from previously existingindustrial communications protocols.
This standard may be used as the basis for formal data link programming interfaces.Nevertheless, it is not a formal programming interface,and any such interface will need toaddress implementation issues not covered by this standard, including:
a) The sizes and octet ordering of various multi-octet service parameters;
b) The correlation of paired primitives for request and confirm,or indication and response.1.3conformance
This standard does not specify individual implementations or products，nor do they constrainthe implementations of data-link entities within industrial automation systems.
There is no conformance of equipment to this data-link layer service definition standard.Instead，conformance is achieved through implementation of the corresponding data-linkprotocol that fulfils the Type 21 DLL services defined in this standard.
2Normative references
The following referenced documents are indispensable for the application of this document.For dated references,only the edition cited applies.For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 61158-2:20101，Industrial communication networks – Fieldbus specifications – Part 2:Physical layer specification and service definition
IEC 61158-4-21:20101,Industrial communication networks – Fieldbus specifications -Part 4-21: Data-link layer protocol specification – Type 21 elements
ISO/IEC 7498-1，Information technology – Open Systems Interconnection – Basic ReferenceModel: The Basic Model
ISO/IEC 7498-3，Information technology – Open Systems Interconnection – Basic ReferenceModel: Naming and addressing
ISO/IEC 8802-3:2000，Information technology – Telecommunications and informationexchange between systems -Local and metropolitan area networks -Specific requirements -Part 3: Carrier sense multiple access with collision detection (CSMA/CD) access method andphysical layer specifications
ISo/IEC 10731:1994，Information technology – Open Systems Interconnection – BasicReference Model-Conventions for the definition of osl services
3 Terms, definitions,symbols, abbreviations, and conventions
3.1 Reference model terms and definitions
This standard is based in part on the concepts developed in ISO/IEC7498-1 andISO/IEC 7498-3, and makes use of the following terms defined therein.
3.1 .1 DL-address [ISO/IEC 7498-3]
3.1 .2 DL-address-mapping [ISO/IEC 7498-1 ]
3.1 .3 called-DL-address [ISO/IEC 7498-3]
3.1.4 calling-DL-address [ISO/IEC 7498-3]
3.1 .5 centralized multi-end-point-connection [ISO/IEC 7498-1 ]
3.1 .6 DL-connection [ISO/IEC 7498-1 ]
3.1 .7 DL-connection-end-point [ISO/IEC 7498-1 ]
3.1 .8 DL-connection-end-point-identifier [ISO/IEC 7498-1 ]
3.1.9 DL-connection-mode transmission [ISO/IEC 7498-1 ]
3.1 .1 0 DL-connectionless-mode transmission [ISO/IEC 7498-1 ]
3.1.1 1 correspondent (N)-entities
correspondent DL-entities (N=2)
correspondent Ph-entities (N=1)
[ISO/IEC 7498-1 ]
3.1 .1 2 DL-duplex-transmission [ISO/IEC 7498-1 ]
3.1 .1 3 (N)-entity
DL-entity (N=2)
Ph-entity (N=1 )
[ISO/IEC 7498-1 ]
3.1 .1 4 DL-facility [ISO/IEC 7498-1 ]
3.1.1 5 flow control [ISO/IEC 7498-1 ]
3.1.1 6 (N)-layer
DL-layer (N=2)
Ph-layer (N=1)
[ISO/IEC 7498-1 ]
3.1.1 7 layer-management [ISO/IEC 7498-1 ]
3.1.1 8 DL-local-view [ISO/IEC 7498-3]
3.1.1 9 DL-name [ISO/IEC 7498-3]
3.1.20 naming-(addressing)-domain [ISO/IEC 7498-3]
3.1.21 peer-entities [ISO/IEC 7498-1 ]
3.1.22 primitive name [ISO/IEC 7498-3]
3.1.23 DL-protocol [ISO/IEC 7498-1 ]
3.1.24 DL-protocol-connection-identifier [ISO/IEC 7498-1 ]
3.1.25 DL-protocol-data-unit [ISO/IEC 7498-1 ]
3.1.26 DL-relay [ISO/IEC 7498-1 ]
3.1.27 Reset [ISO/IEC 7498-1 ]
3.1.28 responding-DL-address [ISO/IEC 7498-3]
3.1.29 Routing [ISO/IEC 7498-1 ]
3.1.30 Segmenting [ISO/IEC 7498-1 ]
3.1.31 (N)-service
DL-service (N=2)
Ph-service (N=1 )
[ISO/IEC 7498-1 ]
3.1.32 (N)-service-access-point
DL-service-access-point (N=2)
Ph-service-access-point (N=1)
[ISO/IEC 7498-1 ]
3.1 .33 DL-service-access-point-address [ISO/IEC 7498-3]
3.1.34 DL-service-connection-identifier [ISO/IEC 7498-1 ]
3.1 .35 DL-service-data-unit [ISO/IEC 7498-1 ]
3.1.36 DL-simplex-transmission [ISO/IEC 7498-1 ]
3.1.37 DL-subsystem [ISO/IEC 7498-1 ]
3.1 .38 systems-management [ISO/IEC 7498-1 ]
3.1 .39 DLS-user-data [ISO/IEC 7498-1 ]