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b) n-Master <--> 1-Slave

An example of the communication relationships of several masters to one slave is

shown in the folowing figure. Thereby master 1 is a diagnostic or configuration

station, master 2 as an intelligent terminal and master 3 is a process master.

Master 1 Slave 1

========= ========

= = = =

= !----------- Acyclic with no ------------%1 =

= ! = Slave Initiative = =

= %%-+ = (Default Management Connection) = =

= ! = = =

= !----------- Acyclic with no ------------% =

= = Slave Initiative = =

========= = =

= =

Master 2 = =

========= = =

= = = =

= !----------- Acyclic with no ------------% =

= ! = Slave Initiative = =

= %%-+ = = =

= ! = = =

= !----------- Cyclic with ----------------% =

= = Slave Initiative = =

========= = =

= =

Master 3 = =

========= = =

= = = =

= %%------------ Acyclic with ---------------% =

= = Slave Initiative = =

========= ========

Figure 18. Communication Relationships between n Masters and 1 Slave

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c) n-Master <--> n-Slaves

An example of the communication relationships of several masters to several

slaves is shown in the following figure.

Master 1 Slave 1

========= ========

= = = =

= !----------- Acyclic with ---------------% =

= ! Slave Initiative = =

= ! = = =

= !---------- Cyclic with -----------------% =

= %%-+ = Slave Initiative = =

= ! = = =

= !--------- Cyclic with no ------+ ========

= ! = Slave Initiative !

= ! = !

= !------ Cyclic with no ----+ !

= = Slave Initiative ! ! Slave 2

========= ! ! ========

! ! = =

! +--------% =

! = =

! ========

!

! Slave 3

! ========

Master 2 ! = =

========= +-------------% =

= = = =

= !---------- Cyclic with -----------------% =

= %%-+ = Slave Initiative = =

= ! = = =

= !---------- Acyclic with -------+ ========

= = Slave Initiative !

========= !

! Slave 4

! ========

! = =

+--------% =

= =

========

Figure 19. Communication Relationships between n Masters and n Slaves

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d) n-Master <--> n-Master

An example of mutual, direct communication relationships between several masters

is shown in the following figure. They occur for example in manufacturing lines,

whereby the manufacturing data is passed on directly with the work piece to the

next process device.

Master 1

========

= =

= %%--------------------------------+

= = !

= %------- Acyclic ---+ !

= = ! !

======== ! !

! !

Master 2 ! !

======== ! !

= = ! !

= %-------------------+ !

= = !

= %%-------------------------+ !

= = ! !

= %------- Acyclic ---+ ! !

= = ! ! !

======== ! ! !

! ! !

Master 3 ! ! !

======== ! ! !

= = ! ! !

= %-------------------+ ! !

= = ! !

= ==== = ! !

= %-------- Cyclic with no --+ !

Slave = = Slave Initiative !

Emula- = = !

tion = %---------- Cyclic with ----------+

= = Slave Initiative

========

Master 3 emulates a slave on both connections for cyclic data transfer.

Figure 20. Communication Relationships between n Masters

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e) Broadcast / Multicast

An example of communication relationships from one master to all other stations

(broadcast), or a subset of them (multicast) is shown in the following figure.

These communication relationships are used for example for the synchronization

of stations or for the transmission of the time or global alarms.

Master 1 Slave 1

======== ========

= = = =

= %--------- Broadcast -------------+--------%%% =

= = ! = =

= %--------- Multicast -----+ ! ========

= = ! !

======== ! !

! ! Master 2

! ! ========

! ! = =

! +--------%%% =

! ! = =

! ! ========

! !

! ! Slave 2

! ! ========

! ! = =

! +--------%%% =

! ! = =

+-------!--------% =

! ! = =

! ! ========

! !

! ! Slave 3

! ! ========

! ! = =

! +--------%%% =

! ! = =

! ! ========

! !

! ! Master 3

! ! ========

! ! = =

! +--------%%% =

! = =

+----------------% =

= =

========

Figure 21. Broadcast / Multicast Communication Relationships

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6.2.3 Interface between the LLI User and LLI

This clause describes the services, their parameters and the sequences of serv-

ice primitives at the interface between the LLI user and LLI.

The LLI services are processed via LLI service access points (LLI SAPs). There

are 2 LLI service access points. The following assignment shall apply:

LLI SAP 0: LLI user = FMS

LLI SAP 1: LLI user = FMA7

The detailed functionality of the services and the sequences at the interface to

Layer 2 and over the bus are described from the chapter connection-oriented com-

munication relationships on.

6.2.4 Overview of Services

The LLI provides the following services at the interface to the LLI user:

- Associate (ASS) : establishment of a connection

- Data Transfer Confirmed (DTC) : data transfer user confirmed

- Abort (ABT) : release of a connection

Optionally, the LLI may additionally provide the following services at the in-

terface to the LLI user:

- Data Transfer Acknowledged (DTA): data transfer LLI confirmed

- Data Transfer Unconfirmed (DTU) : unconfirmed data transfer

Thereby the following definitions are valid:

The LLI user, which issues a service request to its LLI, is called responder.

The LLI user, which receives a service indication for unconfirmed LLI user serv-

ices from its LLI, is called receiver.

The services are described in an abbreviated, tabular form.

The following abbreviations are used in the tables:

.req : request service primitive

.ind : indication service primitive

.res : response service primitive

.con : confirmation service primitive

M : parameter is Mandatory for the primitive

S : parameter is a Selection from a set of two or more

possible parameters

C : parameter is Conditional upon another parameter

Subparameters are indented.

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Associate (ASS)

The Associate service is mandatory. It shall permit the establishment of a logi-

cal LLI connection in conjunction with the transmission of the initiate PDUs of

the LLI user. A logical LLI connection is the prerequisite for the execution of

the services DTC and DTA.

Table 1. Associate (ASS)

+--------------------------------------+-----+-----+

! Parameter Name !.req !.res !

! !.ind !.con !

+--------------------------------------+-----+-----+

! Argument ! M ! !

! Communication Reference ! M ! !

! LLI SAP ! M ! !

! Data ! M ! !

! ! ! !

! Result(+) ! ! S !

! Communication Reference ! ! M !

! LLI SAP ! ! M !

! Data ! ! M !

! ! ! !

! Result(-) ! ! S !

! Communication Reference ! ! M !

! LLI SAP ! ! M !

! Data ! ! M !

+--------------------------------------+-----+-----+

Argument

The argument shall contain the parameters of the ASS.req and ASS.ind primitives.

Communication reference

The parameter specifies the identifier of the associated connection in the LLI

CRL.

LLI SAP

The parameter specifies the LLI service access point over which the service is

executed.

Data

The parameter contains the LLI user PDU (INITIATE_REQ_PDU or FMA7-

INITIATE_REQ_PDU).

Result(+)

The parameter shall indicate that the Associate service was executed success-

fully.

Data

The parameter contains the LLI user PDU (INITIATE_RES_PDU or FMA7-

INITIATE_RES_PDU).

Result(-)

The parameter shall indicate that the Associate service failed.

Data

The parameter contains the LLI user PDU (INITIATE_NRS_PDU or FMA7-

INITIATE_NRS_PDU).

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The following abbreviations are used in the sequences below (see the following

five figures):

R+ : Result(+)

R- : Result(-)

---> : direction of the service primitives

<---

<...> : parameter of a service primitive

CREF : Communication REFerence

LG : Locally Generated

ID : IDentifier

RC : Reason Code

AD : Additional Detail

Execution of the Associate service at the LLI user - LLI interface (the service

primitives are abbreviated as ASS.xxx):

Requester: Responder:

LLI User LLI LLI LLI User

===================!========= =========!=================

! !

ASS.req ! ! ASS.ind

<CREF, LLI SAP, ! ! <CREF, LLI SAP,

Data> ! ! Data>

------------------>!-- --!---------------->

! !

ASS.con ! ! ASS.res

<R+, CREF, LLI SAP,! ! <R+, CREF,

Data> ! ! LLI SAP, Data>

<------------------!-- --!<----------------

! !

or ! ! or

! !

ASS.con ! ! ASS.res

<R-, CREF, LLI SAP,! ! <R-, CREF,

Data> ! ! LLI SAP, Data>

<------------------!-- --!<----------------

! !

Figure 22. Associate Sequence

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Data Transfer Confirmed (DTC)

The service Data Transfer Confirmed is mandatory. It permits the transmission of

the LLI user PDUs for confirmed LLI user services with exception of Initiate

PDUs on connection-oriented communication relationships.

Table 2. Data Transfer Confirmed

+--------------------------------------+-----+-----+

! ! ! !

! Parameter Name !.req !.res !

! !.ind !.con !

+--------------------------------------+-----+-----+

! Argument ! M ! !

! Communication Reference ! M ! !

! LLI SAP ! M ! !

! Data ! M ! !

! ! ! !

! Result ! ! M !

! Communication Reference ! ! M !

! LLI SAP ! ! M !

! Data ! ! M !

+--------------------------------------+-----+-----+

Argument

The argument contains the parameters of the DTC.req and DTC.ind primitives.

Communication reference

The parameter shall specify the identifier of the associated connection in the

LLI CRL.

LLI SAP

The parameter specifies the LLI service access point over which the service is

executed.

Data

The parameter contains the LLI user PDU (confirmed Request PDU).

Result

The parameter shall indicate that the DTC service has been executed.

Data

The parameter contains the LLI user PDU (confirmed Response PDU).

Execution of the service Data Transfer Confirmed at the LLI user - LLI interface

(the service primitives are abbreviated as DTC.xxx):

Requester: Responder:

LLI User LLI LLI LLI User

================!========== ==========!===============

! !

DTC.req ! ! DTC.ind

<CREF, LLI SAP, ! ! <CREF, LLI SAP,

Data> ! ! Data>

--------------->!-- --!-------------->

DTC.con ! ! DTC.res

<CREF, LLI SAP, ! ! <CREF, LLI SAP,

Data> ! ! Data>

<---------------!-- --!<--------------

! !

Figure 23. DTC Sequence

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Data Transfer Acknowledged (DTA)

The service Data Transfer Acknowledged is optional. It permits the transmission

of the LLI user PDUs for unconfirmed LLI user services over connection-oriented

communication relationships.

Table 3. Data Transfer Acknowledged

+----------------------------------+-----+

! ! !

! Parameter Name !.req !

! !.ind !

+----------------------------------+-----+

! Argument ! M !

! Communication Reference ! M !

! LLI SAP ! M !

! Priority ! M !

! Data ! M !

+----------------------------------+-----+

Argument

The argument contains the parameters of the DTA.req and DTA.ind primitives.

Communication reference

The parameter specifies the identifier of the associated connection in the LLI

CRL.

LLI SAP

The parameter specifies the LLI service access point over which the service is

executed.

Priority

The parameter shall indicate the priority of the DTA service. It may take the

value <LOW> (low priority) or <HIGH> (high priority).

Data

The parameter contains the LLI user PDU (unconfirmed request PDU).

Execution of the service Data Transfer Acknowledged at the LLI user - LLI inter-

face (the service primitives are abbreviated as DTA.xxx).

Requester: Receiver:

LLI User LLI LLI LLI User

====================!======= =======!=====================

! !

DTA.req ! ! DTA.ind

<CREF, LLI SAP, ! ! <CREF, LLI SAP,

Priority, Data> ! ! Priority, Data>

------------------->!-- --!-------------------->

! !

Figure 24. DTA Sequence

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Data Transfer Unconfirmed (DTU)

The service Data Transfer Unconfirmed is optional. It permits the transmission

of the LLI user PDUs for unconfirmed LLI user services on connectionless commu-

nication relationships.

Table 4. Data Transfer Unconfirmed

+----------------------------------+-----+

! ! !

! Parameter Name !.req !

! !.ind !

+----------------------------------+-----+

! Argument ! M !

! Communication Reference ! M !

! LLI SAP ! M !

! Priority ! M !

! Data ! M !

+----------------------------------+-----+

Argument

The argument contains the parameters of the DTU.req and DTU.ind primitives.

Communication reference

The parameter specifies the identifier of the associated connection in the LLI

CRL.

LLI SAP

The parameter specifies the LLI service access point over which the service is

executed.

Priority

The parameter shall indicate the priority of the DTU service. It may take the

value <LOW> (low priority) or <HIGH> (high priority).

Data

The parameter contains the LLI user PDU (unconfirmed request PDU).

Execution of the service Data Transfer Unconfirmed at the LLI user - LLI inter-

face (the service primitives are abbreviated as DTU.xxx).

Requester: Receiver:

LLI User LLI LLI LLI User

====================!======= =======!=====================

! !

DTU.req ! ! DTU.ind

<CREF, LLI SAP, ! ! <CREF, LLI SAP,

Priority, Data> ! ! Priority, Data>

------------------->!-- --!-------------------->

! !

Figure 25. DTU Sequence

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