IEC 61158-3-18:2007

IEC 61158-3-18 ®
Edition 1.0 2007-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial communication networks – Fieldbus specifications –
Part 3-18: Data-link layer service definition – Type 18 elements

Réseaux de communications industriels – Spécifications des bus de terrain –
Partie 3-18: Définition du service de la couche de liaison de données –
Eléments de Type 18
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IEC 61158-3-18 ®
Edition 1.0 2007-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial communication networks – Fieldbus specifications –

Part 3-18: Data-link layer service definition – Type 18 elements

Réseaux de communications industriels – Spécifications des bus de terrain –

Partie 3-18: Définition du service de la couche de liaison de données –

Eléments de Type 18
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX T
ICS 25.040.40; 35.100.20 ISBN 978-2-8322-0986-8

– 2 – 61158-3-18 © IEC:2007
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
1.1 Overview . 7
1.2 Specifications . 7
1.3 Conformance . 7
2 Normative references . 8
3 Terms, definitions, symbols, abbreviations and conventions . 8
3.1 Reference model terms and definitions . 8
3.2 Service convention terms and definitions . 9
3.3 Data-link service terms and definitions . 10
3.4 Common symbols and abbreviations . 13
3.5 Conventions . 13
4 Data link services . 15
4.1 Overview . 15
4.2 Primitives of the DLS . 15
4.3 CYCLIC-DATA-UPDATE . 15
4.4 ACYCLIC-DATA-TRANSMIT . 16
4.5 MASTER-TRANSMISSION-TRIGGER. 17
5 DL-management Services . 17
5.1 Overview . 17
5.2 Required services . 17
5.3 ESTABLISH-MASTER-POLLED . 17
5.4 ESTABLISH-SLAVE-POLLED . 18
5.5 ESTABLISH-MASTER-PACKED. 19
5.6 ESTABLISH-SLAVE-PACKED . 19
5.7 RELEASE-CONNECTION . 20
5.8 SUSPEND-CONNECTION . 20
5.9 RESUME-CONNECTION . 20
5.10 ACTIVATE-STANDBY-MASTER. 21
5.11 ERROR . 21
Bibliography . 23

Table 1 – DLE station identifiers . 15
Table 2 – CYCLIC-DATA-UPDATE parameters . 15
Table 3 – ACYCLIC-DATA-TRANSMIT parameters . 16
Table 4 – ESTABLISH-MASTER-POLLED parameters . 18
Table 5 – Baud rate parameter values . 18
Table 6 – ESTABLISH-SLAVE-POLLED parameters . 18
Table 7 – ESTABLISH-MASTER-PACKED parameters . 19
Table 8 – Baud rate parameter values . 19
Table 9 – Bit width parameter values . 19
Table 10 – ESTABLISH-SLAVE-PACKED parameters . 20
Table 11 – RELEASE-CONNECTION parameters . 20
Table 12 – SUSPEND-CONNECTION parameters . 20

61158-3-18 © IEC:2007 – 3 –
Table 13 – RESUME-CONNECTION parameters . 21
Table 14 – ERROR parameters . 21

– 4 – 61158-3-18 © IEC:2007
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 3-18: Data-link layer service definition – Type 18 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
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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
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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.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
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 of their respective intellectual-property-right holders.
International Standard IEC 61158-3-18 has been prepared by subcommittee 65C: Industrial
networks, of IEC technical committee 65: Industrial-process measurement, control and
automation.
This first edition and its companion parts of the IEC 61158-3 subseries cancel and replace
IEC 61158-3:2003. This edition of this part constitutes a technical addition.
This edition includes the following significant changes with respect to 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;

61158-3-18 © IEC:2007 – 5 –
c) division of this part into multiple parts numbered 3-1, 3-2, …, 3-19.
This bilingual version (2013-07) corresponds to the monolingual English version, published in
2007-12.
The text of this standard is based on the following documents:
FDIS Report on voting
65C/473/FDIS 65C/484/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.

– 6 – 61158-3-18 © 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.
Throughout the set of fieldbus standards, the term “service” refers to the abstract capability
provided by one layer of the OSI Basic Reference Model to the layer immediately above. Thus,
the data-link layer service defined in this standard is a conceptual architectural service,
independent of administrative and implementation divisions.

61158-3-18 © IEC:2007 – 7 –
INDUSTRIAL COMMUNICATION NETWORKS –
FIELDBUS SPECIFICATIONS –
Part 3-18: Data-link layer service definition – Type 18 elements

1 Scope
1.1 Overview
This standard provides common elements for basic time-critical and non-time-critical
messaging communications between devices in an automation environment and material
specific to Type 18 fieldbus. The term “time-critical” is used to represent the presence of a
time-window, within which one or more specified actions are required to be completed with
some defined level of certainty. Failure to complete specified actions within the time window
risks failure of the applications requesting the actions, with attendant risk to equipment, plant
and possibly human life.
This standard defines in an abstract way the externally visible service provided by the Type
18 fieldbus 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 which they
take; and
c) the interrelationship between these actions and events, and their valid sequences.
This standard defines the services provided to
• the Type 18 fieldbus application layer at the boundary between the application and data-
link layers of the fieldbus reference model, and
• system management at the boundary between the data-link layer and systems
management of the fieldbus reference model.
1.2 Specifications
The principal objective of this standard is to specify the characteristics of conceptual data-link
layer services suitable for time-critical communications, and thus supplement the OSI Basic
Reference Model in guiding the development of data-link protocols for time-critical
communications. A secondary objective is to provide migration paths from previously-existing
industrial communications protocols.
This specification may be used as the basis for formal DL-Programming-Interfaces.
Nevertheless, it is not a formal programming interface, and any such interface will need to
address implementation issues not covered by this specification, including:
a) the sizes and octet ordering of various multi-octet service parameters, and
b) the correlation of paired request and confirm, or indication and response, primitives.
1.3 Conformance
This standard does not specify individual implementations or products, nor do they constrain
the 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-link
protocol that fulfills the Type 18 data-link layer services defined in this standard.

– 8 – 61158-3-18 © 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.
ISO/IEC 7498-1, Information technology – Open Systems Interconnection – Basic Reference
Model: The Basic Model
ISO/IEC 7498-3, Information technology – Open Systems Interconnection – Basic Reference
Model: Naming and addressing
ISO/IEC 10731, Information technology – Open Systems Interconnection – Basic Reference
Model – Conventions for the definition of OSI services
3 Terms, definitions, symbols, abbreviations and conventions
For the purposes of this document, the following terms, definitions, symbols, abbreviations
and conventions 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.
[ISO/IEC 7498-3]
3.1.1 DL-address
[ISO/IEC 7498-1]
3.1.2 DL-address-mapping
[ISO/IEC 7498-3]
3.1.3 called-DL-address
[ISO/IEC 7498-3]
3.1.4 calling-DL-address
[ISO/IEC 7498-1]
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]
3.1.10 DL-connectionless-mode transmission
[ISO/IEC 7498-1]
3.1.11 correspondent (N)-entities
correspondent DL-entities  (N=2)
correspondent Ph-entities  (N=1)
[ISO/IEC 7498-1]
3.1.12 DL-duplex-transmission
[ISO/IEC 7498-1]
3.1.13 (N)-entity
DL-entity  (N=2)
Ph-entity  (N=1)
[ISO/IEC 7498-1]
3.1.14 DL-facility
[ISO/IEC 7498-1]
3.1.15 flow control
61158-3-18 © IEC:2007 – 9 –
[ISO/IEC 7498-1]
3.1.16 (N)-layer
DL-layer  (N=2)
Ph-layer  (N=1)
[ISO/IEC 7498-1]
3.1.17 layer-management
[ISO/IEC 7498-3]
3.1.18 DL-local-view
[ISO/IEC 7498-3]
3.1.19 DL-name
[ISO/IEC 7498-3]
3.1.20 naming-(addressing)-domain
[ISO/IEC 7498-1]
3.1.21 peer-entities
[ISO/IEC 7498-3]
3.1.22 primitive name
[ISO/IEC 7498-1]
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 7498-3]
3.1.28 responding-DL-address
[ISO/IEC 7498-1]
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 7498-3]
3.1.33 DL-service-access-point-address
[ISO/IEC 7498-1]
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
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 acceptor
3.2.2 asymmetrical service
– 10 – 61158-3-18 © IEC:2007
3.2.3 confirm (primitive);
requestor.deliver (primitive)
3.2.4 deliver (primitive)
3.2.5 DL-confirmed-facility
3.2.6 DL-facility
3.2.7 DL-local-view
3.2.8 DL-mandatory-facility
3.2.9 DL-non-confirmed-facility
3.2.10 DL-provider-initiated-facility
3.2.11 DL-provider-optional-facility
3.2.12 DL-service-primitive;
primitive
3.2.13 DL-service-provider
3.2.14 DL-service-user
3.2.15 DLS-user-optional-facility
3.2.16 indication (primitive);
acceptor.deliver (primitive)
3.2.17 multi-peer
3.2.18 request (primitive);
requestor.submit (primitive)
3.2.19 requestor
3.2.20 response (primitive);
acceptor.submit (primitive)
3.2.21 submit (primitive)
3.2.22 symmetrical service
3.3 Data-link service terms and definitions
3.3.1
DLE station identifier
network address assigned to a DLE
3.3.2
DLE station slot
unit (granularity of one) of position dependent mapping (for cyclic data field) of which a DLE
may occupy one or more, delineated by the range beginning at the DLE station identifier with
a length equal to the configured number of occupied slots
3.3.3
DL-segment, link, local link
single DL-subnetwork in which any of the connected DLEs may communicate directly, without
any intervening DL-relaying, whenever all of those DLEs that are participating in an instance
of communication are simultaneously attentive to the DL-subnetwork during the period(s) of
attempted communication
61158-3-18 © IEC:2007 – 11 –
3.3.4
DLSAP
distinctive point at which DL-services are provided by a single DL-entity to a single higher-
layer entity
NOTE This definition, derived from ISO/IEC 7498-1, is repeated here to facilitate understanding of the critical
distinction between DLSAPs and their DL-addresses.
3.3.5
DL(SAP)-address
either an individual DLSAP-address, designating a single DLSAP of a single DLS-user, or a
group DL-address potentially designating multiple DLSAPs, each of a single DLS-user
NOTE This terminology is chosen because ISO/IEC 7498-3 does not permit the use of the term DLSAP-address
to designate more than a single DLSAP at a single DLS-user.
3.3.6
(individual) DLSAP-address
DL-address that designates only one DLSAP within the extended link
NOTE A single DL-entity may have multiple DLSAP-addresses associated with a single DLSAP.

NOTE 1 DLSAPs and PhSAPs are depicted as ovals spanning the boundary between two adjacent layers.
NOTE 2 DL-addresses are depicted as designating small gaps (points of access) in the DLL portion of a DLSAP.
NOTE 3 A single DL-entity may have multiple DLSAP-addresses and group DL-addresses associated with a
single DLSAP.
Figure 1 – Relationships of DLSAPs, DLSAP-addresses and group DL-addresses
3.3.7
extended link
DL-subnetwork, consisting of the maximal set of links interconnected by DL-relays, sharing a
single DL-name (DL-address) space, in which any of the connected DL-entities may
communicate, one with another, either directly or with the assistance of one or more of those
intervening DL-relay entities
NOTE An extended link may be composed of just a single link.

– 12 – 61158-3-18 © IEC:2007
3.3.8
frame
denigrated synonym for DLPDU
3.3.9
group DL-address
DL-address that potentially designates more than one DLSAP within the extended link
NOTE 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.
3.3.10
master DLE
DLE that performs the functions of network master
3.3.11
master-packed DLE
master DLE that uses the packed response access protocol
3.3.12
master-polled DLE
master DLE that uses the polled response access protocol
3.3.13
node
single DL-entity as it appears on one local link
3.3.14
packed response
transmission of data managed by the process of a master broadcasting a trigger message
whereupon each slave waits a time period unique to its DLE station identifier then transmits
its response resulting in a time-sliced packing of all slave responses triggered by a single
master request
3.3.15
polled response
transmission of data managed by the process of a master individually interrogating each slave
in a request/response paradigm
3.3.16
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.
3.3.17
RWr
DLS-user visible register containing word-oriented cyclic data of type input data that is
transmitted from a slave DLE to a master DLE
3.3.18
RWw
DLS-user visible register containing word-oriented cyclic data of type input data that is
transmitted from a master DLE to a slave DLE
3.3.19
RX
DLS-user visible register containing bit-oriented cyclic data of type input data that is
transmitted from a slave DLE to a master DLE

61158-3-18 © IEC:2007 – 13 –
3.3.20
RY
DLS-user visible register containing bit-oriented cyclic data of type output data that is
transmitted from a master DLE to a slave DLE
3.3.21
sending DLS-user
DL-service user that acts as a source of DLS-user-data
3.3.22
slave DLE
DLE that performs the functions of network slave
3.3.23
slave-packed DLE
slave DLE that uses the packed response access protocol
3.3.24
slave-polled DLE
slave DLE that uses the polled response access protocol
3.4 Common symbols and abbreviations
DL- Data-link layer (as a prefix)
DLC DL-connection
DLCEP DL-connection-end-point
DLE DL-entity (the local active instance of the data-link layer)
DLL DL-layer
DLPCI DL-protocol-control-information
DLPDU DL-protocol-data-unit
DLM DL-management
DLME DL-management Entity (the local active instance of DL-management)
DLMS DL-management Service
DLS DL-service
DLSAP DL-service-access-point
DLSDU DL-service-data-unit
FIFO First-in first-out (queuing method)
OSI Open systems interconnection
Ph- Physical layer (as a prefix)
PhE Ph-entity (the local active instance of the physical layer)
PhL Ph-layer
QoS Quality of service
3.5 Conventions
3.5.1 Basic conventions
This standard uses the descriptive conventions given in ISO/IEC 10731.

– 14 – 61158-3-18 © IEC:2007
The service model, service primitives, and time-sequence diagrams used are entirely abstract
descriptions; they do not represent a specification for implementation.
Service primitives, used to represent service user/service provider interactions (see
ISO/IEC 10731), convey parameters that indicate information available in the user/provider
interaction.
This standard uses a tabular format to describe the component parameters of the DLS
primitives. The parameters that apply to each group of DLS primitives are set out in tables
throughout the remainder of this standard. Each table consists of up to six columns,
containing the name of the service parameter, and a column each for those primitives and
parameter-transfer directions used by the DLS:
 the request primitive’s input parameters;
 the request primitive’s output parameters;
 the indication primitive’s output parameters;
 the response primitive’s input parameters; and
 the confirm primitive’s output parameters.
NOTE The request, indication, response and confirm primitives are also known as requestor.submit,
acceptor.deliver, acceptor.submit, and requestor.deliver primitives, respectively (see ISO/IEC 10731).
One parameter (or part of it) is listed in each row of each table. Under the appropriate service
primitive columns, a code is used to specify the type of usage of the parameter on the
primitive and parameter direction specified in the column:
M — parameter is mandatory for the primitive.
U — parameter is a User option, and may or may not be provided depending
on the dynamic usage of the DLS-user. When not provided, a default
value for the parameter is assumed.
C — parameter is conditional upon other parameters or upon the environment
of the DLS-user.
(blank) — parameter is never present.
Some entries are further qualified by items in brackets. These may be
a) a parameter-specific constraint
(=) indicates that the parameter is semantically equivalent to the parameter in the
service primitive to its immediate left in the table;
b) an indication that some note applies to the entry
(n) indicates that the following note n contains additional information pertaining to the
parameter and its use.
In any particular interface, not all parameters need be explicitly stated. Some may be
implicitly associated with the DLSAP at which the primitive is issued.
In the diagrams which illustrate these interfaces, dashed lines indicate cause-and-effect or
time-sequence relationships, and wavy lines indicate that events are roughly
contemporaneous.
3.5.2 DLE support level
There are three levels of data transmission support for a DLE.
• Level A – supports only bit-oriented cyclic data transmission.
• Level B – includes level A as well as word-oriented cyclic data transmission.
• Level C – includes level B as well as acyclic data transmission.

61158-3-18 © IEC:2007 – 15 –
3.5.3 DLE station identifiers
By convention, certain DLE station identifiers have implied reference to their DLE class as
specified in Table 1.
Table 1 – DLE station identifiers
Value DLE class
0 Master DLE
1 – 64 Slave DLE
128 Standby master DLE
4 Data link services
4.1 Overview
The Type 18 DL specifies a master/slave relationship for data transmission traffic
management. DL-management services are provided to establish connections whereupon a
DLE is instantiated as either a master DLE or a slave DLE.
Once connected, the master DLE scans all connected slave DLEs for cyclic, and for the polled
class acyclic, data under the control of the DLS-user. Cyclic data is transmitted in the same
format (bit-oriented and word-oriented) in every scan. Acyclic data is transmitted as required
in a request/response message format. Only the master-polled DLE is able to generate
acyclic data requests.
4.2 Primitives of the DLS
The DLS provides the following service primitives for data transmission and reception:
• CYCLIC-DATA-UPDATE
• ACYCLIC-DATA-TRANSMIT
• MASTER-TRANSMISSION-TRIGGER.
4.3 CYCLIC-DATA-UPDATE
4.3.1 Parameters
Parameters are listed in Table 2.
Table 2 – CYCLIC-DATA-UPDATE parameters
Parameter name Request Indication
Master status C
Maximum DLE station identifier C
Output data M
Slave status M
Input data M
4.3.2 Master-polled
4.3.2.1 Request
The master status, bit-oriented output register (RY) and, for DLE support level B, word-
oriented output registers (RWw) are updated with the values specified in the DLSDU.

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4.3.2.2 Indication
The slave status, bit-oriented input registers (RX) and, for DLE support level B, word-oriented
input registers (RWr) have been updated with the values specified in the processed DLPDU.
4.3.3 Slave-polled
4.3.3.1 Request
The slave status, bit-oriented input registers (RX) and, for DLE support level B, word-oriented
input registers (RWr) are updated with the values specified in the DLSDU.
4.3.3.2 Indication
The master status, bit-oriented output register (RY) and, for DLE support level B, word-
oriented output registers (RWw) have been updated with the values specified in the
processed DLPDU.
4.3.4 Master-packed
4.3.4.1 Request
The maximum DLE station identifier and the bit-oriented output register (RY) is updated with
the values specified in the DLSDU.
4.3.4.2 Indication
The slave status and the bit-oriented input register (RX) have been updated with the values
specified in the processed DLPDU.
4.3.5 Slave-packed
4.3.5.1 Request
The slave status and the bit-oriented input register (RX) is updated with the values specified
in the DLSDU.
4.3.5.2 Indication
The maximum DLE station identifier and the bit-oriented output register (RY) have been
updated with the values specified in the processed DLPDU.
4.4 ACYCLIC-DATA-TRANSMIT
4.4.1 Parameters
Parameters are listed in Table 3.
Table 3 – ACYCLIC-DATA-TRANSMIT parameters
Parameter name Request Indication Response Confirm
Acyclic message M M(=) M M(=)
4.4.2 Master-polled
4.4.2.1 Request
The master’s acyclic message data is queued with the message from the DLSDU and will be
transmitted upon execution of the next MASTER-TRANSMISSION-TRIGGER request.

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4.4.2.2 Confirmation
A slave’s acyclic message response data has been received.
4.4.3 Slave-polled
4.4.3.1 Indication
A master’s acyclic message request data has been received.
4.4.3.2 Response
The slave’s acyclic message response data is queued with the message from the DLSDU and
will be transmitted along with the slave’s next cyclic data transmission as specified by
Type 18 DL-protocol.
4.5 MASTER-TRANSMISSION-TRIGGER
4.5.1 Parameters
There are no parameters defined for this service.
4.5.2 Request
The MASTER-TRANSMISSION-TRIGGER request is only supported by a master DLE. Receipt of
the MASTER-TRANSMISSION-TRIGGER request causes the master DLE to initiate the master DLE
transmission method defined by the Type 18 DL-protocol.
5 DL-management Services
5.1 Overview
The Type 18 DL specifies a master/slave relationship for data transmission traffic
management. DL-management services are provided to establish connections whereupon a
DLE is instantiated as either a master DLE or a slave DLE.
Once connected, DL-management services are provided to release, suspend and resume
connections. Error indications and other more specialized services are also provided.
5.2 Required services
The DL provides the following service primitive for DL management:
• ESTABLISH-MASTER-POLLED
• ESTABLISH-SLAVE-POLLED
• ESTABLISH-MASTER-PACKED
• ESTABLISH-SLAVE-PACKED
• RELEASE-CONNECTION
• SUSPEND-CONNECTION
• RESUME-CONNECTION
• ACTIVATE-STANDBY-MASTER
• Error
5.3 ESTABLISH-MASTER-POLLED
5.3.1 Parameters
Parameters are listed in Table 4.

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Table 4 – ESTABLISH-MASTER-POLLED parameters
Parameter name Request Confirm
Baud rate M
Master’s status M
Slaves’ status M
Slave’s configuration M
5.3.2 Request
The DL executes the establish master-polled DLE procedure, as defined by the Type 18 DL-
protocol.
The baud rate parameter values are specified in Table 5.
Table 5 – Baud rate parameter values
Value Baud rate (kbit/s)
0 156
1 625
2 2 500
3 5 000
4 10 000
5.3.3 Confirmation
The DLE has been instantiated as a master-polled DLE. The DLSDU contains the slave’s
status fields collected from each slave discovered on the network. The slave’s status
parameter is a position mapped array of 64 elements corresponding to DLE station identifier.
The slave’s configuration parameter is a position mapped array of 65 elements corresponding
to DLE station identifier.
NOTE Although the slave’s configuration structure is a representation of all connected slaves, the one exception
is that DLE station identifier 128 (the 65th element) specifies the configuration of a standby type master-polled DLE.
5.4 ESTABLISH-SLAVE-POLLED
5.4.1 Parameters
Parameters are listed in Table 6.
Table 6 – ESTABLISH-SLAVE-POLLED parameters
Parameter name Request Confirm
Master’s status M
Slaves’ status M
Slave’s configuration M
5.4.2 Request
The DL executes the establish slave-polled DLE procedure, as defined by the Type 18 DL-
protocol.
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5.4.3 Confirmation
The DLE has been instantiated as a slave-polled DLE. The DLSDU contains the master’s
status parameter that was received during the establish slave-polled DLE procedure.
5.5 ESTABLISH-MASTER-PACKED
5.5.1 Parameters
Parameters are listed in Table 7.
Table 7 – ESTABLISH-MASTER-PACKED parameters
Parameter name Request Confirm
Baud rate M
Maximum DLE station identifier M
Bit width M
Slave’s configuration M
5.5.2 Request
The DL executes the establish master-polled DLE procedure, as defined by the Type 18 DL-
protocol.
The baud rate parameter values are specified in Table 8, the maximum DLE station identifier
is in the range of 1 to 64 and the bit width parameter values are specified in Table 9 which
configures the number of bits associated with each DLE station slot.
Table 8 – Baud rate parameter values
Value Baud rate (kbit/s)
0 156
1 625
2 2 500
Table 9 – Bit width parameter values
Value Bit width
1 4
2 8
3 16
5.5.3 Confirmation
The DLE has been instantiated as a master-packed DLE. The DLSDU contains the slave’s
configuration fields collected from each slave discovered on the network. The slave’s
configuration parameter is a position mapped array of 64 elements corresponding to DLE
station identifier.
5.6 ESTABLISH-SLAVE-PACKED
5.6.1 Parameters
Parameters are listed in Table 10.

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Table 10 – ESTABLISH-SLAVE-PACKED parameters
Parameter name Request Confirm
Maximum DLE station identifier M
Bit width M
Slave’s configuration M
5.6.2 Request
The DL executes the establish slave-packed DLE procedure, as defined by the Type 18 DL-
protocol.
5.6.3 Confirmation
The DLE has been instantiated as a slave-packed DLE. The DLSDU contains the maximum
DLE station identifier and the configured bit width parameters that were received during the
establish slave-packed DLE procedure.
5.7 RELEASE-CONNECTION
5.7.1 Parameters
Parameters are listed in Table 11.
Table 11 – RELEASE-CONNECTION parameters
Parameter name Request
DLE station identifier M
5.7.2 Request
The DLE executes the release connection procedure as defined by the Type 18 DL-protocol
whereupon the connection to the requested DLE station is released.
5.8 SUSPEND-CONNECTION
5.8.1 Parameters
Parameters are listed in Table 12.
Table 12 – SUSPEND-CONNECTION parameters
Parameter name Request
DLE station identifier M
5.8.2 Request
The DLE executes the suspend connection procedure as defined by the Type 18 DL-protocol
whereupon the connection to the requested DLE station is suspended.
ESUME-CONNECTION
5.9 R
5.9.1 Parameters
Parameters are listed in Table 13.

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Table 13 – RESUME-CONNECTION parameters
Parameter name Request
DLE station identifiers M
5.9.2 Request
The DLE executes the resume connection procedure as defined by the Type 18 DL-protocol
whereupon the connection to the requested DLE stations are resumed.
For the master DLE class, the DLE station identifier parameter is a list of DLE station
identifiers. This service is only valid for DLE station identifiers that are in the suspended state.
For the slave DLE class, the DLE station identifier parameter is a single DLE station identifier.
This service is only valid for a DLE station identifier that is in the suspended state.
5.10 ACTIVATE-STANDBY-MASTER
5.10.1 Parameters
There are no parameters defined for this service.
5.10.2 Request
This service is only supported by a master-polled DLE that has been configured as a master-
polled DLE with the DLE master type set to standby. It is expected that the DLS-user
performs the appropriate procedures for translating the values of input registers to the values
for output registers and assuming the behavior of a master type DLS-user.
The DLE executes the activate standby master procedure as defined by the Type 18 DL-
protocol and upon successful completion, the DLE becomes a master-polled DLE with the
DLE master type set to active.
5.11 ERROR
5.11.1 Parameters
Parameters are listed in Table 14.
Table 14 – ERROR parameters
Parameter name Indication
Error code M
5.11.2 Indication
The Error indication is sent to the DLS-user in response to events as described in the Type 18
DL-protocol. The status parameter identifies a particular error as listed in the fo
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