IEC 61158-6:2000

Digital data communications for measurement and control - Fieldbus for use in industrial control systems - Part 6: Application Layer protocol specification

Please note that this part is also available as part of a special CD-ROM containing IEC 61158-2 (with 2 amendments), IEC 61158-3, IEC 61158-4, IEC 61158-5 and IEC 61158-6 for a price of CHF 459,00

General Information

• Status: Published
• Publication Date: 26-Jan-2000
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 35.100.70 - Application layer
• ICS: 35.240.50 - IT applications in industry
• Technical Committee: SC 65C - Industrial networks
• Current Stage: DELPUB - Deleted Publication
• Start Date: 27-May-2003
• Completion Date: 26-Oct-2025

Relations

• Replaces: IEC TS 61158-6:1999 - Digital data communications for measurement and control - Fieldbus for use in industrial control systems - Part 6: Application Layer protocol specification
• Effective Date: 05-Sep-2023
• Revised: IEC 61158-6:2003 - Digital data communications for measurement and control - Fieldbus for use in industrial control systems - Part 6: Application layer protocol specification
• Effective Date: 05-Sep-2023

Overview

IEC 61158-6:2000 is the International Electrotechnical Commission (IEC) standard specifying the Application Layer protocol for Fieldbus systems used in industrial control and measurement. As Part 6 of the IEC 61158 Fieldbus series, this second-edition document defines the application-layer syntax, services, object and class models, state-machine conventions and messaging behaviour required to support reliable digital data communications between controllers, I/O devices, instruments and supervisory systems. Note: this part is also sold as part of a consolidated CD-ROM bundle (includes IEC 61158‑2, ‑3, ‑4, ‑5 and ‑6) for CHF 459.00.

Key topics and requirements

• Application layer specification: Abstract syntax and protocol data units (PDUs) for Fieldbus application interactions (e.g., confirmed and unconfirmed send services).
• Object and class model: Definitions for application objects, instances, attributes, class codes and class-specific services to ensure interoperable device behaviour.
• Services and primitives: Common and object-specific services (client/server, producer/consumer models, unconnected services, UCMM) governing data exchange and control.
• Connection types: Point‑to‑point, multicast and cyclic communication models, connection identifiers and path definitions.
• State machines and conventions: Formal state-machine notation and conventions for deterministic behaviour and implementation consistency.
• Diagnostics & configuration: Definitions for device-related diagnosis, configuration identifiers, address assignment and consistency checks to support maintenance and commissioning.
• Terminology & references: Extensive normative references to ISO/IEC standards and IEC vocabularies (e.g., ISO/IEC 7498‑1) plus abbreviations and encoding conventions.

Applications and who uses it

IEC 61158-6 is aimed at professionals and organizations implementing or integrating industrial fieldbus networks, including:

• Device manufacturers building Fieldbus-enabled PLCs, I/O modules, sensors and actuators implementing application-layer behaviour.
• Control system integrators ensuring interoperability across multi-vendor systems and configuring connection types and communication classes.
• Automation software developers implementing protocol stacks, PDUs, state machines and UCMM/unconnected messaging.
• Test and certification labs validating compliance with Fieldbus application-layer requirements.
• Plant engineers and maintenance teams using diagnostic and configuration models for commissioning and troubleshooting distributed control systems.

Related standards

• IEC 61158 series (other parts: ‑2, ‑3, ‑4, ‑5, etc.)
• ISO/IEC references cited in the standard (e.g., ISO/IEC 7498‑1, ISO/IEC 8822, 9545)
• IEC vocabulary and symbol standards (e.g., IEC 60050, IEC 60027, IEC 60417)

Keywords: IEC 61158-6, Fieldbus, application layer, industrial control systems, protocol specification, digital data communications, measurement and control, Fieldbus protocol.

Standards Content (Sample)

INTERNATIONAL
IEC
STANDARD
61158-6
Second edition
2000-01
Digital data communications for
measurement and control –
Fieldbus for use in industrial control systems –
Part 6:
Application Layer protocol specification

Reference number
Numbering
As from 1 January 1997 all IEC publications are issued with a designation in the
60000 series.
Consolidated publications
Consolidated versions of some IEC publications including amendments are

available. For example, edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the
base publication, the base publication incorporating amendment 1 and the base

publication incorporating amendments 1 and 2.

Validity of this publication
The technical content of IEC publications is kept under constant review by the IEC,
thus ensuring that the content reflects current technology.
Information relating to the date of the reconfirmation of the publication is available
in the IEC catalogue.
Information on the subjects under consideration and work in progress undertaken by
the technical committee which has prepared this publication, as well as the list of
publications issued, is to be found at the following IEC sources:
• IEC web site*
• Catalogue of IEC publications
Published yearly with regular updates
(On-line catalogue)*
• IEC Bulletin
Available both at the IEC web site* and as a printed periodical
Terminology, graphical and letter symbols
For general terminology, readers are referred to IEC 60050: International
Electrotechnical Vocabulary (IEV).
For graphical symbols, and letter symbols and signs approved by the IEC for
general use, readers are referred to publications IEC 60027: Letter symbols to be
used in electrical technology, IEC 60417: Graphical symbols for use on equipment.
Index, survey and compilation of the single sheets and IEC 60617: Graphical symbols
for diagrams.
* See web site address on title page.

INTERNATIONAL IEC
STANDARD 61158-6
Second edition
2000-01
Digital data communications for
measurement and control –
Fieldbus for use in industrial control systems –
Part 6:
Application Layer protocol specification
© IEC 2000 – Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: [phone] e-mail: [e-mail] IEC web site http://www.iec.ch
Commission Electrotechnique Internationale
PRICE CODE
XH
International Electrotechnical Commission

For price, see current catalogue

– 2 – 61158-6 © IEC:2000(E)
CONTENTS
INTRODUCTION .22

1 Scope.23

2 Normative references .24

3 Definitions .25

3.1 Definitions from other ISO/IEC Standards .25

3.1.1 Definitions from ISO/IEC 7498-1 .25
3.1.2 Definitions from ISO/IEC 8822 .25
3.1.3 Definitions from ISO/IEC 9545 .25
3.1.4 Definitions from ISO/IEC 8824 .25
3.1.5 Definitions from ISO/IEC 8825 .25
3.2 Definitions from IEC 61158-5 .25
3.3 Other definitions .26
3.3.1 Type 1 Definitions .26
3.3.1.1 called.26
3.3.1.2 calling.26
3.3.1.3 interoperability .26
3.3.1.4 management information.26
3.3.1.5 receiving.26
3.3.1.6 resource .26
3.3.1.7 sending.26
3.3.2 Type 2 Definitions .26
3.3.2.1 Allocate .26
3.3.2.2 Application.26
3.3.2.3 Application objects.26
3.3.2.4 Attribute.26
3.3.2.5 Behaviour .27
3.3.2.6 Class .27
3.3.2.7 Class attributes.27
3.3.2.8 Class code.27
3.3.2.9 Class specific service .27
3.3.2.10 Client.27

3.3.2.11 Connection .27
3.3.2.12 Connection ID (CID).27
3.3.2.13 Connection path.27
3.3.2.14 Connection point.27
3.3.2.15 Consume .27
3.3.2.16 Consumer.27
3.3.2.17 Consuming application.27
3.3.2.18 Cyclic .27
3.3.2.19 Device .27
3.3.2.20 Device profile.28
3.3.2.21 End node .28
3.3.2.22 End point .28
3.3.2.23 Error.28

61158-6 © IEC:2000(E) – 3 –
3.3.2.24 Frame.28

3.3.2.25 Instance.28

3.3.2.26 Instance attributes .28

3.3.2.27 Instantiated.28

3.3.2.28 Keeper.28

3.3.2.29 Little endian .28

3.3.2.30 Lpacket.28

3.3.2.31 Member .28

3.3.2.32 Message router.28

3.3.2.33 Multicast connection .28
3.3.2.34 Network .28
3.3.2.35 Object.28
3.3.2.36 Object specific service .29
3.3.2.37 Originator .29
3.3.2.38 Point-to-point connection .29
3.3.2.39 Produce.29
3.3.2.40 Producer.29
3.3.2.41 Server .29
3.3.2.42 Service .29
3.3.2.43 Target.29
3.3.2.44 Temporary node.29
3.3.2.45 Transaction id.29
3.3.2.46 Unconnected message manager (UCMM) .29
3.3.2.47 Unconnected service.29
3.3.3 Type 3 Definitions .29
3.3.3.1 Access Protection .29
3.3.3.2 Address-assignment-table.29
3.3.3.3 Channel.29
3.3.3.4 Channel related Diagnosis .30
3.3.3.5 Configuration check .30
3.3.3.6 Configuration fault .30
3.3.3.7 Configuration Identifier.30
3.3.3.8 Configuration Identifier related Diagnosis .30
3.3.3.9 Control Commands .30
3.3.3.10 Data consistency .30

3.3.3.11 Default address .30
3.3.3.12 Device related diagnosis .30
3.3.3.13 Diagnosis information .30
3.3.3.14 Diagnosis information collection .30
3.3.3.15 DP-Master (Class 1) .30
3.3.3.16 DP-Master (Class 2) .30
3.3.3.17 DP-Slave .30
3.3.3.18 Freeze .30
3.3.3.19 Group .30
3.3.3.20 I/O data .31
3.3.3.21 Ident Number.31
3.3.3.22 Index .31
3.3.3.23 Master parameter set.31

– 4 – 61158-6 © IEC:2000(E)
3.3.3.24 Module .31

3.3.3.25 Process data.31

3.3.3.26 Real Configuration .31

3.3.3.27 Slot.31

3.3.3.28 Sync .31

3.3.4 Type 4 Definitions .31

3.3.5 Type 5 Definitions .31

3.3.6 Type 6 Definitions .31

3.3.7 Type 7 Definitions .31

3.3.8 Type 8 Definitions .31
3.4 Abbreviations and symbols.31
3.4.1 Type 1 Abbreviations and symbols .31
3.4.2 Type 2 Abbreviations and symbols .32
3.4.3 Type 3 Abbreviations and symbols .32
3.4.4 Type 4 Abbreviations and symbols .33
3.4.5 Type 5 Abbreviations and symbols .33
3.4.6 Type 6 Abbreviations and symbols .33
3.4.7 Type 7 Abbreviations and symbols .33
3.4.8 Type 8 Abbreviations and symbols .34
3.5 Conventions .34
3.5.1 Conventions for Type 1 .34
3.5.1.1 Conventions for Class Definitions.34
3.5.1.2 Abstract Syntax Conventions.34
3.5.2 Conventions for Type 2 .34
3.5.2.1 Attribute specification.34
3.5.2.2 Common Services.35
3.5.3 Conventions for Type 3 .38
3.5.3.1 Abstract Syntax Conventions.38
3.5.3.2 Convention for the Encoding of Reserved Bits and Octets .38
3.5.3.3 Conventions for the Common Coding Structure of specific Field Octets .38
3.5.4 Conventions for Type 4 .39
3.5.5 Conventions for Type 5 .39
3.5.6 Conventions for Type 6 .39
3.5.7 Conventions for Type 7 .39
3.5.8 Conventions for Type 8 .39

3.6 Conventions used in State Machines.39
3.6.1 Conventions for Type 1 .39
3.6.2 Conventions for Type 2 .40
3.6.2.1 State Machine Conventions.40
3.6.3 Conventions for Type 3 .42
3.6.4 Conventions for Type 4 .44
3.6.5 Conventions for Type 5 .44
3.6.6 Conventions for Type 6 .44
3.6.7 Conventions for Type 7 .44
3.6.7.1 Evaluation networks.45
3.6.7.2 Simple actions .45
3.6.7.3 Conditions .45
3.6.8 Conventions for Type 8 .45

61158-6 © IEC:2000(E) – 5 –
4 Type 1.46

4.1 FAL Syntax Description.46

4.1.1 FAL-AR PDU Abstract Syntax 1.46

4.1.1.1 Confirmed Send Service .46

4.1.1.2 Unconfirmed Send Service.46

4.1.1.3 Unconfirmed Acknowledged Send Service.46

4.1.1.4 Idle Send Service.47

4.1.1.5 AR-XON-OFF Send Service .47

4.1.1.6 Establish Service .47

4.1.2 FAL-AR PDU Abstract Syntax 2.47
4.1.2.1 Confirmed Send Service .47
4.1.2.2 Unconfirmed Send Service.48
4.1.2.3 Unconfirmed Acknowledged Send Service.48
4.1.2.4 Idle Send Service.48
4.1.2.5 AR-XON-OFF Send Service .48
4.1.2.6 Establish Service .48
4.1.2.7 MaxOSCC .49
4.1.2.8 MaxOSCS.49
4.1.2.9 MaxUCSC.49
4.1.2.10 MaxUCSS.49
4.1.2.11 XON_OFF.49
4.1.2.12 CIU.49
4.1.3 Abstract Syntax of PDUBody .49
4.1.3.1 Abort Service .49
4.1.3.2 InvokeID .49
4.1.3.3 ConfirmedServiceRequest.50
4.1.3.4 ConfirmedServiceResponse .51
4.1.3.5 ConfirmedServiceError.52
4.1.3.6 Error Type .52
4.1.3.7 Error Class .53
4.1.3.8 Unconfirmed PDUs .54
4.1.3.9 Management ASE .54
4.1.3.10 Application Process ASE.56
4.1.3.11 Load Region ASE.57
4.1.3.12 Function Invocation ASE .59

4.1.3.13 Variable Access ASE .60
4.1.3.14 Event Management ASE .63
4.1.3.15 Type Definitions .66
4.1.4 Data Types .82
4.1.4.1 Notation for the Boolean Type .82
4.1.4.2 Notation for the Integer Type.82
4.1.4.3 Notation for the Unsigned Type .82
4.1.4.4 Notation for the Floating Point Type .82
4.1.4.5 Notation for the BitString Type .83
4.1.4.6 Notation for the OctetString Type .83
4.1.4.7 Notation for VisibleString Type .83
4.1.4.8 Notation for the UNICODEString Type.83
4.1.4.9 Notation for the FieldbusTime Type.83

– 6 – 61158-6 © IEC:2000(E)
4.1.4.10 Notation for the Universal Time Type .83

4.1.4.11 Notation for Binary Time Type.83

4.1.4.12 Notation for BCD Type .83

4.1.4.13 Notation for Compact Boolean Array Type .83

4.1.4.14 Notation for Compact BCD Array Type .83

4.1.4.15 Notation for BinaryDate Type .83

4.1.4.16 Notation for TimeOfDay Type .83

4.1.4.17 Notation for TimeDifference Type.83

4.1.4.18 Notation for TimeValue Type.83

4.1.5 Reason Codes .84
4.1.5.1 Introduction.84
4.2 Transfer Syntaxes.85
4.2.1 Transfer Syntax 1 .85
4.2.1.1 FAL Header .85
4.2.1.2 Traditional Encoding Rule (TER) .86
4.2.1.3 Compact Encoding Rule (CER) .94
4.3 FAL Protocol State Machines Structure .109
4.4 AP Context State Machine .110
4.4.1 Primitive Definitions .110
4.4.1.1 Primitives Exchanged between FAL-User and AP-Context .110
4.4.2 State Machine Description.110
4.4.3 AP-AP Context Initiation State Transitions.111
4.4.4 Functions.122
4.5 FAL Service Protocol Machine (FSPM).125
4.5.1 Primitive Definitions .125
4.5.1.1 Primitives Exchanged between AP_Context and FSPM.125
4.5.1.2 Parameters of AP_Context /FSPM Primitives .126
4.5.2 FSPM State Tables .127
4.5.2.1 Functions.130
4.6 Application Relationship Protocol Machines (ARPMs).131
4.6.1 Queued Usertriggered Unidirectional (QUU) ARPM .131
4.6.1.1 Primitive Definitions .131
4.6.1.2 Parameters of FSPM/ARPM Primitives .131
4.6.1.3 QUU ARPM State Machine.134
4.6.2 Queued Usertriggered Bidirectional-Connection Oriented (QUB-CO) ARPM.137

4.6.2.1 Primitive Definitions .137
4.6.2.2 DLL Mapping of QUB AREP Class .137
4.6.2.3 QUB AREP State Machine .141
4.6.3 Queued Usertriggered Bidirectional-Connectionless (QUB-Cl) ARPM.150
4.6.3.1 Primitive Definitions .150
4.6.3.2 DLL Mapping of QUB-CL AREP Class .150
4.6.3.3 QUB-CL ARPM State Machine .152
4.6.4 Queued Usertriggered Bidirectional-Segmentation (QUB-Seg) ARPM .157
4.6.4.1 Primitive Definitions .157
4.6.4.2 Parameters of FSPM/ARPM Primitives .157
4.6.4.3 QUB-Seg ARPM State Machine.161
4.6.5 Queued Usertriggered Bidirectional-Flow Control (QUB-FC) ARPM.175
4.6.5.1 QUB-FCPrimitive Definitions .175

61158-6 © IEC:2000(E) – 7 –
4.6.5.2 Parameters of FSPM/ARPM Primitives .176

4.6.5.3 QUB-FC ARPM State Machine .179

4.6.6 Buffered Usertriggered Bidirectional (BUB) ARPM .201

4.6.6.1 Primitive Definitions .201

4.6.6.2 DLL Mapping of BUB AREP Class.202

4.6.6.3 BUB ARPM State Machine .205

4.6.7 Buffered Networkscheduled Bidirectional (BNB) ARPM.216

4.6.7.1 Primitive Definitions .216

4.6.7.2 Primitives issued by ARPM to FSPMParameters of FSPM/ARPM Primitives216

4.6.7.3 DLL Mapping of BNB AREP Class.217
4.6.7.4 BNB ARPM state machine.220
4.6.8 Buffered Networkscheduled Unidirectional (BNU) ARPM .240
4.6.8.1 Primitive Definitions .240
4.6.8.2 DLL Mapping of BNU AREP Class.241
4.6.8.3 BNU AREP State Machine.244
4.6.9 Buffered Networkscheduled Unidirectional-MP (BNU-MP) ARPM .251
4.6.9.1 Primitive Definitions .251
4.6.9.2 DLL Mapping of BNU-MP AREP Class .252
4.6.9.3 BNU-MP ARPM State Machine.255
4.7 DLL Mapping Protocol Machine (DMPM) .263
4.7.1 Primitive Definitions .263
4.7.1.1 Primitives Exchanged between DMPM and ARPM .263
4.7.1.2 Parameters of ARPM/DMPM Primitives .265
4.7.1.3 Primitives Exchanged between Data Link Layer and DMPM.266
4.7.1.4 Parameters of DMPM/Data Link Layer Primitives.267
4.7.2 DMPM State Machine.268
4.7.2.1 DMPM States.268
4.7.2.2 DMPM State Table.268
4.7.2.3 Functions used by DMPM.274
4.7.3 Data Link Layer Service Selection .276
4.7.3.1 Introduction.276
4.8 Protocol Options .276
4.8.1 Protocol Option 1 .276
4.8.1.1 Introduction.276
4.8.1.2 Abstract Syntax Selection .277

4.8.1.3 Protocol Machine Overview .277
4.8.1.4 Application Relationship Protocol Machine (ARPM) Selection .277
4.8.1.5 Encoding Rule Selection .277
4.8.2 Protocol Option 2 .277
4.8.2.1 Introduction.277
4.8.2.2 Abstract Syntax.278
4.8.2.3 Protocol Machine Overview .278
4.8.3 Protocol Option 3 .279
4.8.3.1 Introduction.279
4.8.3.2 Abstract Syntax.279
4.8.3.3 Protocol Machine Overview .279
5 Type 2.280
5.1 Type 2 Abstract Syntax .280

– 8 – 61158-6 © IEC:2000(E)
5.1.1 FAL PDU Abstract Syntax .280

5.1.1.1 PDU Structure .280

5.1.1.2 UCMM_PDUs .281

5.1.1.3 Transport_Headers .282

5.1.1.4 CM_PDUs.284

5.1.1.5 CM PDU Components .290

5.1.1.6 MR Headers .297

5.1.1.7 OM_Service_PDU .297

5.1.1.8 Message and Connection Paths .306

5.1.1.9 Class, Attribute And Service Codes.312
5.1.1.10 Error Codes .316
5.1.2 Data Abstract Syntax Specification.325
5.1.2.1 Transport Format Specification .325
5.1.2.2 Abstract Syntax Notation.326
5.1.2.3 Control Network Data Specification .326
5.1.2.4 Data Type Specification / Dictionaries .327
5.2 Type 2 Transfer Syntax.330
5.2.1 Compact Encoding.330
5.2.1.1 Encoding Rules.330
5.2.1.2 Encoding Constraints .330
5.2.1.3 Examples (Informative) .330
5.2.2 Data Type Reporting .336
5.2.2.1 Object Data Representation .336
5.2.2.2 Elementary Data Type Reporting.337
5.2.2.3 Constructed Data Type Reporting.337
5.3 Structure of Type 2 FAL Protocol State Machines.341
5.4 Type 2 AP Context State Machine .341
5.5 FAL Service Protocol Machine (FSPM).341
5.5.1 Primitive Definitions .341
5.5.2 Parameters of Primitives .344
5.5.3 FSPM State Machines.345
5.6 Application Relationship Protocol Machines (ARPMs).345
5.6.1 Connection-less ARPM (UCMM).345
5.6.1.1 Primitive Definitions .346
5.6.1.2 Parameters of Primitives .347

5.6.1.3 UCMM State Machines.347
5.6.1.4 Examples of UCMM Sequences (Informative).353
5.6.1.5 Management UCMM .354
5.6.2 Connection-oriented ARPMs (Transports) .355
5.6.2.1 Transport PDU Buffer .355
5.6.2.2 Transport Classes.355
5.6.2.3 Common Primitive Definitions .356
5.6.2.4 Parameters of Common Primitives .357
5.6.2.5 Transport State Machines – Class 0.357
5.6.2.6 Transport State Machines – Class 1.360
5.6.2.7 Transport State Machines – Class 2.367
5.6.2.8 Transport State Machines – Class 3.374
5.6.2.9 Transport State Machines – Classes 4, 5, 6 .382

61158-6 © IEC:2000(E) – 9 –
5.6.2.10 Transport State Machines – Class 4.391

5.6.2.11 Transport State Machines – Class 5.397

5.6.2.12 Transport State Machines – Class 6.410

5.7 DLL Mapping Protocol Machine (DMPM) .429

5.7.1 Introduction.429

5.7.1.1 Link Producer .429

5.7.1.2 Link Consumer .429

5.7.2 Primitive Definitions .429

5.7.2.1 Primitives Exchanged between DMPM and ARPM .429

5.7.2.2 Parameters of ARPM/DMPM Primitives .430
5.7.2.3 Primitives Exchanged between Data Link Layer and DMPM.430
5.7.2.4 Parameters of DMPM/Data Link Layer Primitives.430
5.7.3 DMPM State Machine.431
5.7.3.1 DMPM States.431
5.7.3.2 Functions used by DMPM.432
5.7.4 Data Link Layer Service Selection .432
5.8 Protocol Options .432
6 Type 3.433
6.1 FAL Syntax Description.433
6.1.1 APDU Abstract Syntax .433
6.1.2 Data Types .435
6.2 Transfer Syntax .435
6.2.1 Coding of Basic Data Types .435
6.2.2 Coding Section related to Data Exchange PDUs .436
6.2.2.1 Coding of the Field Outp_Data .436
6.2.2.2 Coding of the Field Inp_Data.436
6.2.3 Coding Section related to Slave Diagnosis PDUs.436
6.2.3.1 Coding of the Field Station_status_1 .436
6.2.3.2 Coding of the Field Station_status_2 .437
6.2.3.3 Coding of the Field Station_status_3 .437
6.2.3.4 Coding of the Field Diag_Master_Add .437
6.2.3.5 Coding of the Field Ident_Number .437
6.2.3.6 Coding of the Field Header_Byte.437
6.2.3.7 Coding of the Field Alarm_Type .438
6.2.3.8 Coding of the Field Status_Type.438

6.2.3.9 Coding of the Field Slot_Number.439
6.2.3.10 Coding of the Field Alarm_Specifier .439
6.2.3.11 Coding of the Field Status_Specifier.439
6.2.3.12 Coding of the Field Diagnosis_User_Data .439
6.2.3.13 Coding of the Field Modul_Status_Array.439
6.2.3.14 Coding of the Field Identifier_Diagnosis_Data_Array .441
6.2.3.15 C
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