IEC 61158-4-12:2007

IEC 61158-4-12 ®
Edition 1.0 2007-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – Fieldbus specifications –
Part 4-12: Data-link layer protocol specification – Type 12 elements

Réseaux de communication industriels – Spécification des bus de terrain –
Partie 4-12: Spécification du protocole de la couche liaison de données –
Éléments de Type 12
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IEC 61158-4-12 ®
Edition 1.0 2007-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – Fieldbus specifications –

Part 4-12: Data-link layer protocol specification – Type 12 elements

Réseaux de communication industriels – Spécification des bus de terrain –

Partie 4-12: Spécification du protocole de la couche liaison de données –

Éléments de Type 12
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XG
ICS 25.040.40; 35.100.20 ISBN 978-2-8322-1490-9

– 2 – IEC 61158-4-12:2007 © IEC 2007
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 10
3 Terms, definitions, symbols and abbreviations . 10
4 Overview of the DL-protocol . 23
5 Frame structure . 27
6 Attributes . 48
7 DL-user memory . 92
8 Type 12: FDL protocol state machines . 98
Annex A (informative) Type 12: Additional specifications on DL-Protocol state
machines . 106
Bibliography . 142

Figure 1 – Type description example . 19
Figure 2 – Common structure of specific fields . 20
Figure 3 – Frame structure. 24
Figure 4 – Mapping of data in a frame . 25
Figure 5 – Slave node reference model . 26
Figure 6 – Type 12 PDUs embedded in Ethernet frame . 27
Figure 7 – Type 12 PDUs embedded in UDP/IP . 27
Figure 8 – DL information type description . 50
Figure 9 – Address type description . 52
Figure 10 – DL control type description . 54
Figure 11 – DL status type description . 56
Figure 12 – Successful write sequence to DL-user control register . 58
Figure 13 – Successful read sequence to the DL-user status register . 58
Figure 14 – RX error counter type description . 65
Figure 15 – Lost link counter type description . 66
Figure 16 – Additional counter type description . 67
Figure 17 – Sync configuration type description . 68
Figure 18 – Watchdog divider type description . 68
Figure 19 – Sync manager watchdog type description . 69
Figure 20 – Sync manager watchdog status type description . 69
Figure 21 – Watchdog counter type description . 70
Figure 22 – Slave information interface access type description . 70
Figure 23 – Slave information interface control/status type description . 72
Figure 24 – Slave information interface address type description . 74
Figure 25 – Slave information interface data type description . 75
Figure 26 – MII control/status type description . 76
Figure 27 – MII address type description . 77

Figure 28 – MII data type description . 78
Figure 29 – FMMU mapping example . 78
Figure 30 – FMMU entity type description . 79
Figure 31 – SyncM mailbox interaction . 82
Figure 32 – SyncM buffer allocation . 82
Figure 33 – SyncM buffer interaction . 83
Figure 34 – Handling of write/read toggle with read mailbox . 84
Figure 35 – Sync manager channel type description . 86
Figure 36 – Distributed clock local time parameter type description . 90
Figure 37 – Successful write sequence to mailbox . 93
Figure 38 – Bad write sequence to mailbox . 94
Figure 39 – Successful read sequence to mailbox . 94
Figure 40 – Bad read sequence to mailbox . 95
Figure 41 – Successful write sequence to buffer . 96
Figure 42 – Successful read sequence to buffer. 97
Figure 43 – Structuring of the protocol machines of an slave . 98
Figure 44 – Slave information interface read operation . 100
Figure 45 – Slave information interface write operation . 101
Figure 46 – Slave information interface reload operation . 102
Figure 47 – Distributed clock . 104
Figure 48 – Delay measurement sequence . 105

Table 1 – PDU element description example . 19
Table 2 – Example attribute description . 20
Table 3 – State machine description elements . 21
Table 4 – Description of state machine elements . 22
Table 5 – Conventions used in state machines . 22
Table 6 – Transfer Syntax for bit sequences . 28
Table 7 – Transfer syntax for data type Unsignedn . 29
Table 8 – Transfer syntax for data type Integern . 29
Table 9 – Type 12 frame inside an Ethernet frame . 30
Table 10 – Type 12 frame inside an UDP PDU . 31
Table 11 – Type 12 frame structure containing Type 12 PDUs . 32
Table 12 – Type 12 frame structure containing network variables . 32
Table 13 – Type 12 frame structure containing mailbox . 32
Table 14 – Auto increment physical read (APRD) . 33
Table 15 – Configured address physical read (FPRD) . 34
Table 16 – Broadcast read (BRD) . 35
Table 17 – Logical read (LRD) . 36
Table 18 – Auto Increment physical write (APWR) . 37
Table 19 – Configured address physical write (FPWR) . 38
Table 20 – Broadcast write (BWR) . 39
Table 21 – Logical write (LWR) . 40

– 4 – IEC 61158-4-12:2007 © IEC 2007
Table 22 – Auto increment physical read write (APRW) . 41
Table 23 – Configured address physical read write (FPRW) . 42
Table 24 – Broadcast read write (BRW) . 43
Table 25 – Logical read write (LRW) . 44
Table 26 – Auto increment physical read multiple write (ARMW) . 45
Table 27 – Configured address physical read multiple write (FRMW) . 46
Table 28 – Network variable . 47
Table 29 – Mailbox . 47
Table 30 – Error Reply Service Data . 48
Table 31 – DL information . 51
Table 32 – Configured station address . 53
Table 33 – DL control . 54
Table 34 – DL status . 57
Table 35 – DLS-user specific registers . 59
Table 36 – DLS-user event . 61
Table 37 – DLS-user event mask . 62
Table 38 – External event . 63
Table 39 – External event mask . 64
Table 40 – RX error counter . 65
Table 41 – Lost link counter . 66
Table 42 – Additional counter . 67
Table 43 – Watchdog divider . 68
Table 44 – DLS-user watchdog . 68
Table 45 – Sync manager channel watchdog . 69
Table 46 – Sync manager watchdog Status . 69
Table 47 – Watchdog counter . 70
Table 48 – Slave information interface size . 71
Table 49 – Slave information interface control/status . 73
Table 50 – Actual slave information interface address . 74
Table 51 – Actual slave information interface data . 75
Table 52 – MII control/status . 76
Table 53 – Actual MII address. 77
Table 54 – Actual MII data . 78
Table 55 – Fieldbus memory management unit (FMMU) entity . 80
Table 56 – Fieldbus memory management unit (FMMU) . 81
Table 57 – Sync manager channel . 86
Table 58 – Sync manager Structure . 88
Table 59 – Distributed clock local time parameter . 91
Table 60 – Distributed clock DLS-user parameter . 92
Table A.1 – Primitives issued by DHSM to PSM . 106
Table A.2 – Primitives issued by PSM to DHSM . 106
Table A.3 – Parameters used with primitives exchanged between DHSM and PSM . 106
Table A.4 – Identifier for the octets of a Ethernet frame . 107

Table A.5 – DHSM state table . 109
Table A.6 – DHSM function table . 125
Table A.7 – Primitives issued by SYSM to DHSM . 125
Table A.8 – Primitives issued by DHSM to SYSM . 126
Table A.9 – Primitives issued by DL-User to SYSM . 126
Table A.10 – Primitives issued by SYSM to DL-User . 126
Table A.11 – Parameters used with primitives exchanged between SYSM and DHSM . 126
Table A.12 – SYSM state table . 128
Table A.13 – SYSM function table . 138
Table A.14 – Primitives issued by RMSM to SYSM . 138
Table A.15 – Primitives issued by SYSM to RMSM . 138
Table A.16 – Parameters used with primitives exchanged between RMSM and SYSM . 138
Table A.17 – RMSM state table. 140
Table A.18 – RMSM function table . 141

– 6 – IEC 61158-4-12:2007 © IEC 2007
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 4-12: Data-link layer protocol specification – Type 12 elements

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
NOTE Use of some of the associated protocol types is restricted by their intellectual-property-right holders. In all
cases, the commitment to limited release of intellectual-property-rights made by the holders of those rights permits
a particular data-link layer protocol type to be used with physical layer and application layer protocols in Type
combinations as specified explicitly in the IEC 61784 series. Use of the various protocol types in other
combinations may require permission from their respective intellectual-property-right holders.
International Standard IEC 61158-4-12 has been prepared by subcommittee 65C: Industrial
networks, of IEC technical committee 65: Industrial-process measurement, control and
automation.
This bilingual version (2014-06) corresponds to the English version, published in 2007-12.
This first edition and its companion parts of the IEC 61158-4 subseries cancel and replace
IEC 61158-4:2003. This edition of this part constitutes a technical addition, which also
replaces IEC/PAS 62407, published in 2005.
This edition of IEC 61158-4 includes the following significant changes from the previous
edition:
a) deletion of the former Type 6 fieldbus, and the placeholder for a Type 5 fieldbus data link
layer, for lack of market relevance;
b) addition of new types of fieldbuses;
c) division of this part into multiple parts numbered -4-1, -4-2, …, -4-19.
The text of this standard is based on the following documents:
FDIS Report on voting
65C/474/FDIS 65C/485/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under http://webstore.iec.ch in the
data related to the specific publication. At this date, the publication will be:
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
NOTE The revision of this standard will be synchronized with the other parts of the IEC 61158 series.
The list of all the parts of the IEC 61158 series, under the general title Industrial
communication networks – Fieldbus specifications, can be found on the IEC web site.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 8 – IEC 61158-4-12:2007 © IEC 2007
INTRODUCTION
This part of IEC 61158 is one of a series produced to facilitate the interconnection of
automation system components. It is related to other standards in the set as defined by the
“three-layer” fieldbus reference model described in IEC/TR 61158-1.
The data-link protocol provides the data-link service by making use of the services available
from the physical layer. The primary aim of this standard is to provide a set of rules for
communication expressed in terms of the procedures to be carried out by peer data-link
entities (DLEs) 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:
a) as a guide for implementors and designers;
b) for use in the testing and procurement of equipment;
c) as part of an agreement for the admittance of systems into the open systems environment;
d) as a refinement to the understanding of time-critical communications within OSI.
This standard is concerned, in particular, with the communication and interworking of sensors,
effectors and other automation devices. By using this standard together with other standards
positioned within the OSI or fieldbus reference models, otherwise incompatible systems may
work together in any combination.

INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 4-12: Data-link layer protocol specification – Type 12 elements

1 Scope
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
a) in a synchronously-starting cyclic manner, and
b) in a cyclic or acyclic asynchronous manner, as requested each cycle 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
a) procedures for the transfer of data and control information from one data-link user entity to
one or more user entity;
b) the structure of the 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
a) the interactions between DL-entities (DLEs) through the exchange of DLPDUs;
b) the interactions between a DL-service (DLS) provider and a DLS-user in the same system
through the exchange of DLS primitives;
c) the interactions between a DLS-provider and the MAC services of ISO/IEC 8802-3.
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 reference
model, 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 part of this standard does not contain tests to demonstrate compliance with
such requirements.
– 10 – IEC 61158-4-12:2007 © IEC 2007
2 Normative 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 edition
of the referenced document (including any amendments) applies.
IEC 61158-2 (Ed.4.0), Industrial communication networks – Fieldbus specifications – Part 2:
Physical layer specification and service definition
IEC 61158-3-12, Industrial communication networks – Fieldbus specifications – Part 3-12:
Data-link layer service definition – Type 12 elements
IEC 61588, Precision clock synchronization protocol for networked measurement and control
system
ISO/IEC 7498-1, Information technology – Open Systems Interconnection – Basic Reference
Model – Basic Reference Model: The Basic Model
ISO/IEC 7498-3, Information technology – Open Systems Interconnection – Basic Reference
Model – Basic Reference Model: Naming and addressing
ISO/IEC 8802-1(E), ANSI/IEEE Std 802.1 Local and metropolitan area networks – Virtual
bridged local area networks.
ISO/IEC 8802-3:2000, Information technology – Telecommunications and information
exchange between systems – Local and metropolitan area networks – Specific requirements –
Part 3: Carrier sense multiple access with collision detection (CSMA/CD) access method and
Physical Layer specifications
ISO/IEC 9899, Programming Languages – C.
ISO/IEC 10731, Information technology – Open Systems Interconnection – Basic Reference
Model – Conventions for the definition of OSI services
IEEE 802.1Q, IEEE Standard for Local and metropolitan area networks – Virtual Bridged Local
Area Networks; available at
IETF RFC 768, User PDU Protocol; available at
IETF RFC 791, Internet Protocol; available at
3 Terms, definitions, symbols and abbreviations
For the purposes of this document, the following terms, definitions, symbols and abbreviations
apply.
3.1 Reference model terms and definitions
This standard is based in part on the concepts developed in ISO/IEC 7498-1 and ISO/IEC
7498-3, and makes use of the following terms defined therein.
3.1.1 DL-duplex-transmission
[7498-1]
3.1.2 DL-protocol [7498-1]
3.1.3 DL-protocol-data-unit
[7498-1]
3.1.4 (N)-entity [7498-1]
DL-entity
Ph-entity
3.1.5 (N)-interface-data-unit [7498-1]
DL-service-data-unit  (N=2)
Ph-interface-data-unit  (N=1)
3.1.6 (N)-layer [7498-1]
DL-layer  (N=2)
Ph-layer  (N=1)
3.1.7 (N)-service [7498-1]
DL-service  (N=2)
Ph-service  (N=1)
3.1.8 (N)-service-access-point [7498-1]
DL-service-access-point  (N=2)
Ph-service-access-point  (N=1)
3.1.9 (N)-service-access-point-address [7498-1]
DL-service-access-point-address  (N=2)
Ph-service-access-point-address  (N=1)
3.1.10 peer-entities [7498-1]
3.1.11 Ph-interface-data [7498-1]
3.1.12 primitive name [7498-3]
3.1.13 reassembling [7498-1]
3.1.14 recombining [7498-1]
3.1.15 reset [7498-1]
3.1.16 routing [7498-1]
3.1.17 segmenting [7498-1]
3.1.18 sequencing [7498-1]
3.1.19 splitting [7498-1]
3.1.20 systems-management [7498-1]
3.2 Service convention terms and definitions
This standard also makes use of the following terms defined in ISO/IEC 10731 as they apply
to the data-link layer:
3.2.1 asymmetrical service
3.2.2 confirm (primitive);
requestor.deliver (primitive)
3.2.3 deliver (primitive)
3.2.4 DL-service-primitive;
primitive
3.2.5 DL-service-provider
3.2.6 DL-service-user
– 12 – IEC 61158-4-12:2007 © IEC 2007
3.2.7 indication (primitive)
acceptor.deliver (primitive)
3.2.8 request (primitive);
requestor.submit (primitive)
3.2.9 requestor
3.2.10 response (primitive);
acceptor.submit (primitive)
3.2.11 submit (primitive)
3.2.12 symmetrical service
3.3 Common terms and definitions
NOTE Many definitions are common to more than one protocol Type; they are not necessarily used by all protocol
Types.
For the purpose of this part of IEC 61158, the following definitions also apply:
3.3.1
frame
denigrated synonym for DLPDU
3.3.2
group DL-address
DL-address that potentially designates more than one DLSAP within the extended link. A
single DL-entity may have multiple group DL-addresses associated with a single DLSAP. A
single DL-entity also may have a single group DL-address associated with more than one
DLSAP
3.3.3
node
single DL-entity as it appears on one local link
3.3.4
receiving DLS-user
DL-service user that acts as a recipient of DLS-user-data
NOTE A DL-service user can be concurrently both a sending and receiving DLS-user.
3.3.5
sending DLS-user
DL-service user that acts as a source of DLS-user-data
3.4 Additional Type 12 definitions
3.4.1
application
function or data structure for which data is consumed or produced [IEC 61158-5:2003]
3.4.2
application objects
multiple object classes that manage and provide a run time exchange of messages across the
network and within the network device
3.4.3
basic slave
slave device that supports only physical addressing of data

3.4.4
bit
unit of information consisting of a 1 or a 0. This is the smallest data unit that can be
transmitted
3.4.5
client
1) object which uses the services of another (server) object to perform a task
2) initiator of a message to which a server reacts
3.4.6
connection
logical binding between two application objects within the same or different devices
3.4.7
cyclic
events which repeat in a regular and repetitive manner
3.4.8
Cyclic Redundancy Check (CRC)
residual value computed from an array of data and used as a representative signature for the
array
3.4.9
data
generic term used to refer to any information carried over a Fieldbus
3.4.10
data consistency
means for coherent transmission and access of the input- or output-data object between and
within client and server
3.4.11
device
physical entity connected to the fieldbus composed of at least one communication element
(the network element) and which may have a control element and/or a final element
(transducer, actuator, etc.) [IEC 61158-2:2003]
3.4.12
distributed clocks
method to synchronize slaves and maintain a global time base
3.4.13
error
discrepancy between a computed, observed or measured value or condition and the specified
or theoretically correct value or condition
3.4.14
event
instance of a change of conditions

– 14 – IEC 61158-4-12:2007 © IEC 2007
3.4.15
Fieldbus Memory Management Unit
function that establishes one or several correspondences between logical addresses and
physical memory
3.4.16
Fieldbus Memory Management Unit entity
single element of the fieldbus memory management unit: one correspondence between a
coherent logical address space and a coherent physical memory location
3.4.17
full slave
slave device that supports both physical and logical addressing of data
3.4.18
interface
shared boundary between two functional units, defined by functional characteristics, signal
characteristics, or other characteristics as appropriate
3.4.19
master
device that controls the data transfer on the network and initiates the media access of the
slaves by sending messages and that constitutes the interface to the control system
3.4.20
mapping
correspondence between two objects in that way that one object is part of the other object
3.4.21
medium
cable, optical fibre, or other means by which communication signals are transmitted between
two or more points
NOTE "media" is used as the plural of medium.
3.4.22
message
ordered series of octets intended to convey information
NOTE Normally used to convey information between peers at the application layer.
3.4.23
network
set of nodes connected by some type of communication medium, including any intervening
repeaters, bridges, routers and lower-layer gateways
3.4.24
node
end-point of a link in a network or a point at which two or more links meet [derived from IEC
61158-2]
3.4.25
object
abstract representation of a particular component within a device
NOTE An object can be
1) an abstract representation of the capabilities of a device. Objects can be composed of any or all of the following
components:
a) data (information which changes with time);
b) configuration (parameters for behavior);
c) methods (things that can be done using data and configuration);
2) a collection of related data (in the form of variables) and methods (procedures) for operating on that data that
have clearly defined interface and behavior.
3.4.26
process data
data object containing application objects designated to be transferred cyclically or acyclically
for the purpose of processing
3.4.27
server
object which provides services to another (client) object
3.4.28
service
operation or function than an object and/or object class performs upon request from another
object and/or object class
3.4.29
slave
DL-entity accessing the medium only after being initiated by the preceding slave or
3.4.30
Sync manager
collection of control elements to coordinate access to concurrently used objects.
3.4.31
Sync manager channel
single control elements to coordinate access to concurrently used objects.
3.4.32
switch
MAC bridge as defined in IEEE 802.1D
3.5 Common symbols and abbreviations
NOTE Many symbols and abbreviations are common to more than one protocol Type; they are not necessarily
used by all protocol Types.
3.5.1 DL- Data-link layer (as a prefix)
3.5.2 DLC DL-connection
3.5.3 DLCEP DL-connection-end-point
3.5.4 DLE DL-entity (the local active instance of the data-link layer)
3.5.5 DLL DL-layer
– 16 – IEC 61158-4-12:2007 © IEC 2007
3.5.6 DLPCI DL-protocol-control-information
3.5.7 DLPDU DL-protocol-data-unit
3.5.8 DLM DL-management
3.5.9 DLME DL-management Entity (the local active instance of
DL-management)
3.5.10 DLMS DL-management Service
3.5.11 DLS DL-service
3.5.12 DLSAP DL-service-access-point
3.5.13 DLSDU DL-service-data-unit
3.5.14 FIFO First-in first-out (queuing method)
3.5.15 OSI Open systems interconnection
3.5.16 Ph- Physical layer (as a prefix)
3.5.17 PhE Ph-entity (the local active instance of the physical layer)
3.5.18 PhL Ph-layer
3.5.19 QoS Quality of service
3.6 Additional Type 12 symbols and abbreviations
3.6.1 AL Application layer
3.6.2 DLSDU Data-link protocol data unit
3.6.3 APRD Auto increment physical read
3.6.4 APRW Auto increment physical read write
3.6.5 APWR Auto increment physical write
3.6.6 ARMW Auto increment physical read multiple
...