BS EN 61158-4-21:2012:2013 Edition
$215.11
Industrial communication networks. Fieldbus specifications – Data-link layer protocol specification. Type 21 elements
| Published By | Publication Date | Number of Pages |
| BSI | 2013 | 110 |
1.1 General
The DLL provides basic time-critical data communications between devices in an automated environment. Type 21 provides priority-based cyclic and acyclic data communication using an internal collision-free, full-duplex dual-port Ethernet switch technology. For wide application in various automation applications, Type 21 does not restrict the cyclic/acyclic scheduling policy in the DLL.
1.2 Specifications
This standard describes:
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procedures for the timely transfer of data and control information from one data link user entity to a peer user entity, and among the data link entities forming the distributed data link service provider;
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procedures for giving communication opportunities based on standard ISO/IEC 8802-3 MAC, with provisions for nodes to be added or removed during normal operation;
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structure of the fieldbus data link protocol data units (DLPDUs) used for the transfer of data and control information by the protocol of this standard, and their representation as physical interface data units.
1.3 Procedures
The procedures are defined in terms of:
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the interactions between peer data link entities (DLEs) through the exchange of fieldbus DLPDUs;
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the interactions between a data link service (DLS) provider and a DLS-user in the same system through the exchange of DLS primitives;
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the interactions between a DLS-provider and a physical layer service provider in the same system through the exchange of Ph-service primitives.
1.4 Applicability
These procedures are applicable to instances of communication between systems that support time-critical communications services in the data link layer of the OSI or fieldbus reference models, and that require the ability to interconnect in an open systems interconnection environment. Profiles provide a simple multi-attribute means of summarizing an implementation’s capabilities, and thus its applicability to various time-deterministic communications needs.
1.5 Conformance
This standard also specifies conformance requirements for systems implementing these procedures. This standard does not contain tests to demonstrate compliance with such requirements.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 6 | CONTENTS |
| 10 | INTRODUCTION |
| 12 | 1 Scope 1.1 General 1.2 Specifications 1.3 Procedures 1.4 Applicability |
| 13 | 1.5 Conformance 2 Normative references 3 Terms, definitions, symbols and abbreviations 3.1 Reference model terms and definitions |
| 15 | 3.2 Service convention terms and definitions |
| 16 | 3.3 Common terms and definitions |
| 17 | Figures Figure 1 – Relationships of DLSAPs, DLSAP addresses, and group DL addresses |
| 19 | 3.4 Symbols and abbreviations |
| 20 | 4 Overview of the data-link protocol 4.1 General 4.2 Overview of medium access control |
| 21 | 4.3 Service assumed from the physical layer 4.4 DLL architecture Figure 2 – Interaction of PhS primitives with DLE |
| 22 | Figure 3 – Data-link layer architecture Tables Table 1 – DLL components |
| 23 | 4.5 Data type |
| 24 | Table 2 – UNSIGNEDn data type |
| 25 | 4.6 Local parameters and variables Table 3 – INTEGERn data type |
| 26 | Table 4 – DLE configuration parameters |
| 27 | Table 5 – Queues to support data transfer |
| 28 | Table 6 – Variables to support SAP management Table 7 – Variables to support device information management |
| 29 | Table 8 – DL–entity identifier Table 9 – Device Flags Table 10 – DLM state |
| 30 | Table 11 – Device Unique Identification Table 12 – Unique identification of device connected to R-port1 Table 13 – Unique identification of device connected to R-port2 Table 14 – MAC address |
| 31 | Table 15 – Port information Table 16 – Protocol version |
| 32 | Table 17 – Device type Table 18 – Device description Table 19 – Hop count |
| 33 | Table 20 – Variables to support managing network information Table 21 – Topology Table 22 – Collision count |
| 34 | Table 23 – Device count Table 24 – Topology change count Table 25 – Last topology change time Table 26 – RNMP device UID |
| 35 | Table 27 – RNMS device UID Table 28 – LNM device UID for R-port1 Table 29 – LNM device UID for R-port2 |
| 36 | Table 30 – Network flags |
| 37 | Table 31 – Variables and counter to support managing path information |
| 38 | Table 32 – Hop count for R-port1 direction Table 33 – Hop count for R-port2 direction Table 34 – Preferred R-port Table 35 – Destination R-port |
| 39 | Table 36 – In net count Table 37 – In net time |
| 40 | 5 General structure and encoding 5.1 Overview 5.2 MAPDU structure and encoding Table 38 – Out net count Table 39 – Out net time |
| 41 | 5.3 Common MAC frame structure, encoding and elements of procedure Figure 4 – Common MAC frame format for Type 21 DLPDU Figure 5 – MAC frame format for other protocols |
| 42 | Figure 6 – Version and Length field |
| 43 | Figure 7 – DST_addr field Table 40 – Version and Length Table 41 – Destination DL–entity identifier |
| 44 | Figure 8 – SRC_addr field Table 42 – Source DL–entity identifier |
| 45 | Figure 9 – Frame Control Field Table 43 – Frame control |
| 47 | Figure 10 – Extension field Table 44 – Extension |
| 48 | Figure 11 – DSAP field Figure 12 – Source service access point field Table 45 – Destination service access point Table 46 – source service access point |
| 49 | 5.4 Order of bit transmission 5.5 Invalid DLPDU Figure 13 – Length of group mask and extension information Figure 14 – Group mask option field |
| 50 | 6 DLPDU structure and procedure 6.1 General 6.2 Common DLPDU Field 6.3 DL DATA Transfer Figure 15 – Common DLPDU field |
| 51 | Figure 16 – Building a DT DLPDU Figure 17 – DT DLPDU structure Table 47 – DT DLPDU parameters |
| 53 | 6.4 DL SPDATA Transfer Table 48 – Primitives exchanged between DLS user and DLE to send a DT DLPDU Table 49 – Primitives exchanged between DLS user and DLEs to receive a DT DLPDU |
| 54 | Figure 18 – SPDT DLPDU structure Table 50 – SPDT DLPDU Parameters |
| 55 | 6.5 Network control messages Table 51 – Primitive exchanged between DLS User and DLEs to send an SPDT DLPDU Table 52 – Primitives exchanged between DLS user and DLEs to receive an SPDT DLPDU |
| 56 | Figure 19 – NCM_LA DLPDU structure Table 53 – NCM_LA DLPDU parameters |
| 57 | Table 54 – NCM_AT DLPDU parameters |
| 58 | Table 55 – NCM_LS DLPDU parameters |
| 59 | Table 56 – NCM_RS DLPDU parameters |
| 60 | Table 57 – NCM_AR DLPDU parameters |
| 61 | 7 DLE elements of procedure 7.1 Overall structure 7.2 DL protocol machine (DLPM) Figure 20 – DLL structure and elements |
| 62 | Table 58 – Primitives exchanged between DLPM and DLS user |
| 63 | Table 59 – Parameters exchanged between DLPM and DLS user |
| 64 | Table 60 – Primitives exchanged between DLPM and DLM |
| 65 | Figure 21 – State transition diagram of the DLPM Table 61 – Parameters used with primitives exchanged between DLPM and DLM |
| 66 | Table 62 – DLPM state table |
| 70 | Table 63 – DLPM functions table |
| 71 | 7.3 DLL management Protocol |
| 72 | Table 64 – Primitives exchanged between DLM and DLS user |
| 73 | Table 65 – Parameters used with primitives exchanged between DLM and DLS user Table 66 – Primitive exchanged between DLM and DMAC |
| 74 | Table 67 – Parameters used with primitives exchanged between DLM and DMAC Table 68 – Primitive exchanged between DLM and DPHY Table 69 – Parameters used with primitives exchanged between DLM and DPHY |
| 75 | Figure 22 – State transition diagram of DLM |
| 77 | Table 70 – DLM state table |
| 102 | Table 71 – DLM function table |
| 104 | 8 Constants and error codes 8.1 General 8.2 Constants |
| 105 | Table 72 – DLL constants |
| 106 | 8.3 Data-link layer error codes Table 73 – Type 21 DLL error codes |
| 107 | Bibliography |
