1.1 General

The data-link layer provides basic time-critical messaging communications between devices in an automation environment.

This protocol provides communication opportunities to all participating data-link entities

in a synchronously-starting cyclic manner, according to a pre-established schedule, or
in an acyclic manner, as requested by each of those data-link entities.

Thus this protocol can be characterized as one which provides cyclic and acyclic access asynchronously but with a synchronous restart of each cycle.

1.2 Specifications

This standard specifies

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 datalink service provider;
procedures for giving communications opportunities to all participating DL-entities, sequentially and in a cyclic manner for deterministic and synchronized transfer at cyclic intervals up to 64 ms;
procedures for giving communication opportunities available for time-critical data transmission together with non-time-critical data transmission without prejudice to the time-critical data transmission;
procedures for giving cyclic and acyclic communication opportunities for time-critical data transmission with prioritized access;
procedures for giving communication opportunities based on standard ISO/IEC 8802-3 medium access control, with provisions for nodes to be added or removed during normal operation;
the structure of the fieldbus 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

the interactions between peer DL-entities (DLEs) through the exchange of fieldbus DLPDUs;
the interactions between a DL-service (DLS) provider and a DLS-user in the same system through the exchange of DLS primitives;
the interactions between a DLS-provider and a Ph-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 which support time-critical communications services within the data-link layer of the OSI or fieldbus reference models, and which 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-critical 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	English CONTENTS
10	INTRODUCTION
12	1 Scope 1.1 General 1.2 Specifications 1.3 Procedures
13	1.4 Applicability 1.5 Conformance 2 Normative references
14	3 Terms, definitions, symbols, abbreviations and conventions 3.1 Reference model terms and definitions
15	3.2 Service convention terms and definitions 3.3 Common terms and definitions
17	3.4 Symbols and abbreviations
18	3.5 Additional type 24 symbols and abbreviations
19	3.6 Common Conventions
20	3.7 Additional Type 24 conventions Tables Table 1 – State transition descriptions Table 2 – Description of state machine elements Table 3 – Conventions used in state machines
21	4 Overview of DL-protocol 4.1 Characteristic feature of DL-protocol Table 4 – Characteristic features of the fieldbus data-link protocol
22	4.2 DL layer component 4.3 Timing sequence Figures Figure 1 – Data-link layer component
23	Figure 2 – Timing chart of fixed-width time slot type cyclic communication
25	Figure 3 – Timing chart of configurable time slot type cyclic communication
27	Figure 4 – Schematic Diagram of Communication Interrupt Occurrence
29	Figure 5 – Timing relationship between cyclic transmission and data processing
30	4.4 Service assumed from PhL Figure 6 – Timing chart example of acyclic communication
31	4.5 Local parameters, variable, counters, timers Table 5 – List of the values of variable Cyc_sel
32	Table 6 – List of the values of variable Tunit
34	Table 7 – List of the values of variable PDUType Table 8 – List of the values of variable SlotType
36	5 DLPDU structure 5.1 Overview Table 9 – Transfer syntax for bit sequences
37	5.2 Basic format DLPDU structure Figure 7 – Basic format DLPDU structure Table 10 – Bit order
38	Table 11 – Destination and Source address format Table 12 – Station address Table 13 – Extended address Table 14 – Message control field format (Information transfer format)
39	Table 15 – Message control field format (Supervisory format) Table 16 – The list of Supervisory function bits Table 17 – Frame type and Data length format
40	Table 18 – The list of Frame type Table 19 – Data format of Synchronous frame
41	Table 20 – The field list of Synchronous frame Table 21 – Data format of Output data or Input data frame Table 22 – The field list of Output data or Input data frame
42	Table 23 – Data format of Delay measurement start frame Table 24 – The field list of Delay measurement start frame Table 25 – Data format of Delay measurement frame Table 26 – The field list of Delay measurement frame
43	Table 27 – Data format of Status frame Table 28 – The field list of Status frame Table 29 – The list of the DLE status
44	Table 30 – The list of Repeater status Table 31 – Data format of Delay measurement frame Table 32 – The field list of Cycle Information frame
45	5.3 Short format DLPDU structure Figure 8 – Short format DLPDU structure Table 33 – Data format of Message frame Table 34 – The field list of Message frame
46	Table 35 – Range of Station address field Table 36 – Control field format (I/O data exchange format) Table 37 – Control field format (Message format)
47	Table 38 – The field list of Message format Table 39 – Data format of Synchronous frame
48	Table 40 – The field list of Sync frame Table 41 – Data format of Output data frame Table 42 – The field list of Output data frame Table 43 – Data format of Input data frame Table 44 – The field list of Input data frame
49	6 DLE element procedure 6.1 Overview 6.2 Cyclic transmission control sublayer Table 45 – The primitives and parameters for DLS-user interface issued by DLS-user Table 46 – The primitives and parameters for DLS-user interface issued by CTC
51	Figure 9 – The state diagram of C1 master for fixed-width time slot Table 47 – The state table of C1 master for fixed-width time slot
57	Figure 10 – The state diagram of C2 master for fixed-width time slot
58	Table 48 – The state table of C2 master for fixed-width time slot
61	Figure 11 – The state diagram of slave for fixed-width time slot Table 49 – The state table of slave for fixed-width time slot
64	Figure 12 – The state diagram of C1 master for configurable time slot Table 50 – The state table of C1 master for configurable time slot
72	Figure 13 – The state diagram of C2 master for configurable time slot
73	Table 51 – The state table of C2 master for configurable time slot
75	Figure 14 – The state diagram of slave for configurable time slot Table 52 – The state table of slave for configurable time slot
77	Table 53 – The list of functions used by cyclic transmission machine
79	Figure 15 – The state diagram of message initiator for basic format Table 54 – The state table of message initiator for basic format
83	Figure 16 – The state diagram of message responder for basic format Table 55 – The state table of message responder for basic format
87	Figure 17 – The state diagram of message initiator for short format Table 56 – The state table of message initiator for short format
91	Figure 18 – The state diagram of message responder for short format Table 57 – The state table of message responder for short format
95	Table 58 – List of functions used by the message segmentation machine
96	Figure 19 – The state diagram of acyclic transmission protocol machine Table 59 – The state table of acyclic transmission protocol machine
97	Table 60 – The list of functions used acyclic transmission protocol machine
98	6.3 Send Receive Control Table 61 – Primitives and parameters exchanged between CTC and DLM Table 62 – Error event primitive and parameters
99	Table 63 – primitives and parameters for SRC-CTC interface Table 64 – Send frame primitive and parameters Table 65 – Receive frame primitives and parameters
100	Figure 20 – Internal architecture of one-port SRC Figure 21 – Internal architecture of multi-port SRC Figure 22 – Internal architecture of serializer
102	Figure 23 – Internal architecture of deserializer
104	Table 66 – Primitives and parameters exchanged between SRC and DLM
105	7 DL-management layer (DLM) 7.1 Overview 7.2 Primitive definitions Table 67 – Get value primitive and parameters Table 68 – Error event primitive and parameters Table 69 – The list of primitives and parameters (DLMS-user source)
106	7.3 DLM protocol machine Table 70 – The list of primitives and parameters (DLM source)
107	Figure 24 – State diagram of C1 master DLM Table 71 – State table of C1-Master DLM
112	Figure 25 – State diagram of Slave and C2 master DLM Table 72 – State table of Slave and C2 master DLM
115	7.4 Functions Table 73 – The list of the functions used by DLM protocol machine
117	Bibliography

Published By	Publication Date	Number of Pages
BSI	2014	120


PDF Format	Searchable	Printable	Preview Now

Status	Withdrawn
Title	Industrial communication networks. Fieldbus specifications – Data-link layer protocol specification. Type 24 elements
Publisher	BSI
Committee	GEL/65/3
Pages	120
Publication Date	2014-11-30
Withdrawn Date	2022-05-31
Replaced By	BS EN IEC 61158-4-24:2019
ISBN	978 0 580 79450 6
Standard Number	BS EN 61158-4-24:2014
Identical National Standard Of	EN 61158-4-24:2014, IEC 61158-4-24:2014
Descriptors	Communication networks, Industrial, Computer networks, Bus networks, Interfaces (data processing), Process control, Automatic control systems, Communication procedures, Open systems interconnection, Data transmission, Fieldbus, Application layer (OSI)
ICS Codes	25.040.40 - Industrial process measurement and control

BS EN 61158-4-24:2014

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