Спецификация протокола Profibus
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Page 411
PROFIBUS-Specification-Normative-Parts-6:1997
Copyright by PNO 1997 - all rights reserved
Master/Requester . Master/Responder
.
FMA7/ . FMA7/
User!FMS LLI FDL BUS FDL LLI FMS !User
=====!====!=============!======.======!=============!====!=====
INI.req ! ! ! !
<#7> ! ! ! !
----> ! ! ! !
[INI_REQ_ ! ! ! !
PDU] ! ! ! !
ASS.req ! ! ! !
<#7,LLI ! ! ! !
SAP,INI_ ! ! ! !
REQ_PDU> ! ! ! !
---->![ASS_REQ_PDU]! ! !
!"start T1 ! ! !
!\CN open: ! ! !
!"activate ! ! !
! FDL LSAP ! ! !
! ! ! !
! !**INI_REQ_PDU! !
!(FDL_DATA_ !*ASS_REQ_PDU !(FDL_DATA_ !
! ACK.req) ![SDA_REQ_PDU]! ACK.ind) !
! ]------>!------------>!-------->] !
! [<------!<-----------/! !
!(FDL_DATA_ ![SDA_ACK_PDU]!\LLI LLI !
! ACK.con) ! ! Context Test!
! ! ! negative !
! ! ![ABT_REQ_PDU]!
! ! !"start T2 !
ABT.ind ! ! ! !
<#7,LLI ! ! ! !
SAP,LG, ! !*ABT_REQ_PDU !(FDL_DATA_ !
ID,RC,AD>! ![SDA_REQ_PDU]! ACK.req) !
<----!<------------!<------------!<-------[ !
!(FDL_DATA_ !\----------->!------->] !
! ACK.ind) ![SDA_ACK_PDU]!(FDL_DATA_ !
ABO.ind ! ! ! ACK.con) !
<#7,LG,ID,! ! ! !
RC,AD> ! ! ! !
<---- !"stop T1 ! ! !
!\CN open: ! !"stop T2 !
!"start T2 ! ! !
!"deactivate ! ! !
! FDL LSAP ! ! !
!"stop T2 ! ! !
! ! ! !
Figure 50. Master-Master Communication Relationship / Connection
Establishment / LLI-LLI Context Test negative
The sequence for the local error "CRL-Entry faulty" is the same for master-
master and master-slave communication relationships.
Page 412
PROFIBUS-Specification-Normative-Parts-6:1997
Copyright by PNO 1997 - all rights reserved
Master/Requester . Master/Responder
.
FMA7/ . FMA7/
User!FMS LLI FDL BUS FDL LLI FMS !User
=====!====!=============!======.======!=============!====!=====
INI.req ! ! ! !
<#7> ! ! ! !
----> ! ! ! !
[INI_REQ_ ! ! ! !
PDU] ! ! ! !
ASS.req ! ! ! !
<#7,LLI ! ! ! !
SAP,INI_ ! ! ! !
REQ_PDU> ! ! ! !
---->! ! ! !
!\CN in LLI ! ! !
! still in ! ! !
! Data Trans- ! ! !
! fer Phase ! ! !
ABT.ind ![ABT_REQ_PDU]! ! !
<#7,LLI !"start T2 ! ! !
SAP,LG, ! ! ! !
ID,RC,AD>! ! ! !
<----!<-----] ! ! !
! ! ! !
! ! ! !
ABO.ind ! ! ! !
<#7,LG,ID,! ! ! !
RC,AD> !(FDL_DATA_ !*ABT_REQ_PDU !(FDL_DATA_ !
<---- ! ACK.req) ![SDA_REQ_PDU]! ACK.ind) !
! ]------>!------------>!-------->] !
! [<------!<-----------/! !
!(FDL_DATA_ ![SDA_ACK_PDU]!\CN in LLI !
! ACK.con) ! ! released: !
! ! !"ignore Data !
!\CN open: ! ! !
!"deactivate ! ! !
! FDL LSAP ! ! !
! ! ! !
!"stop T2 ! ! !
! ! ! !
Figure 51. Master-Master Communication Relationship / Connection
Establishment / local Error: Connection still established
in local LLI
Page 413
PROFIBUS-Specification-Normative-Parts-6:1997
Copyright by PNO 1997 - all rights reserved
Master/Requester . Master/Responder
.
FMA7/ . FMA7/
User!FMS LLI FDL BUS FDL LLI FMS !User
=====!====!=============!======.======!=============!====!=====
INI.req ! ! ! !
<#7> ! ! ! !
----> ! ! ! !
[INI_REQ_ ! ! ! !
PDU] ! ! ! !
ASS.req ! ! ! !
<#7,LLI ! ! ! !
SAP,INI_ ! ! ! !
REQ_PDU> ! ! ! !
---->![ASS_REQ_PDU]! ! !
!"start T1 ! ! !
!\CN open: ! ! !
!"activate ! ! !
! FDL LSAP ! ! !
! !**INI_REQ_PDU! !
!(FDL_DATA_ !*ASS_REQ_PDU !(FDL_DATA_ !
! ACK.req) ![SDA_REQ_PDU]! ACK.ind) !
! ]------>!------------>!-------->] !
! [<------!<-----------/! !
!(FDL_DATA_ ![SDA_ACK_PDU]!\CN in LLI !
! ACK.con) ! ! still in !
! ! ! Data Trans- !
! ! ! fer Phase !
! ! ! !
! ! ![ABT_REQ_PDU]!
! ! ! !
ABT.ind ! ! !"start T2 !
<#7,LLI ! ! ! !
SAP,LG, ! !*ABT_REQ_ PDU!(FDL_DATA_ !
ID,RC,AD>! ![SDA_REQ_PDU]! ACK.req) !
<----!<------------!<------------!<-------[ !
!(FDL_DATA_ !\----------->!------->] !ABT.ind
! ACK.ind) ![SDA_ACK_PDU]!(FDL_DATA_ !<#9,LLI
ABO.ind ! ! ! ACK.con) !SAP,LG,
<#7,LG,ID,! ! ! !ID,RC,AD>
RC,AD> ! ! ! ]---->!---->
<---- !"stop T1 ! ! !
! ! !\CN open: ! ABO.ind
!\CN open: ! !"deactivate ! <#9,LG,
!"start T2 ! ! FDL Access ! ID,RC,AD>
!"deactivate ! ! Protection ! ---->
! FDL LSAP ! ! !
!"stop T2 ! !"stop T2 !
! ! ! !
Figure 52. Master-Master Communication Relationship / Connection
Establishment / Error: Connection still established in remote LLI
Page 414
PROFIBUS-Specification-Normative-Parts-6:1997
Copyright by PNO 1997 - all rights reserved
Master/Requester . Master/Responder
.
FMA7/ . FMA7/
User!FMS LLI FDL BUS FDL LLI FMS !User
=====!====!=============!======.======!=============!====!=====
INI.req ! ! ! !
<#7> ! ! ! !
----> ! ! ! !
[INI_REQ_ ! ! ! !
PDU] ! ! ! !
ASS.req ! ! ! !
<#7,LLI ! ! ! !
SAP,INI_ ![ASS_REQ_PDU]! ! !
REQ_PDU> !"start T1 ! ! !
!\CN open: ! ! !
!"activate ! ! !
! FDL LSAP ! ! !
! !**INI_REQ_PDU! !
!(FDL_DATA_ !*ASS_REQ_PDU !(FDL_DATA_ !
! ACK.req) ![SDA_REQ_PDU]! ACK.ind) !
! ]------>!------------>!-------->] !
! [<------!<-----------/! !
!(FDL_DATA_ ![SDA_ACK_PDU]!"start T1 !
! ACK.con) ! ! !ASS.ind
! ! !\LLI-LLI !<#9,LLI
! ! ! Context Test!SAP,INI_
!\T1 expired ! ! positive !REQ_PDU>
! ! ! ]---->!---->
! ! !\CN open: !
! ! !"activate !
! ! ! FDL Access !
![ABT_REQ_PDU]! ! Protection !
! ! ! !
!"start T2 ! ! ! INI.ind
! ! ! ! <#9>
!(FDL_DATA_ !*ABT_REQ_PDU !(FDL_DATA_ ! ---->
! ACK.req) ![SDA_REQ_PDU]! ACK.ind) !
! ]------>!------------>!------------>!---->
ABT.ind ! [<------!<-----------/! !ABT.ind
<#7,LLI !(FDL_DATA_ ![SDA_ACK_PDU]! !<#9,LLI
SAP,LG, ! ACK.con) ! ! !SAP,LG,
ID,RC,AD>! ! ! !ID,RC,AD>
<----!<----] ! !"stop T1 !
! ! !\CN open: ! ABO.ind
!\CN open: ! !"start T2 ! <#9,LG,
ABO.ind !"deactivate ! !"deactivate ! ID,RC,AD>
<#7,LG,ID,! FDL LSAP ! ! FDL Access ! ---->
RC,AD> ! ! ! Protection !
<---- !"stop T2 ! !"stop T2 !
! ! ! !
Figure 53. Master-Master Communication Relationship / Connection
Establishment / Error: T1 expired at the Re quester
Page 415
PROFIBUS-Specification-Normative-Parts-6:1997
Copyright by PNO 1997 - all rights reserved
Master/Requester . Master/Responder
.
FMA7/ . FMA7/
User!FMS LLI FDL BUS FDL LLI FMS !User
=====!====!=============!======.======!=============!====!=====
INI.req ! ! ! !
<#7> ! ! ! !
----> ! ! ! !
[INI_REQ_ ! ! ! !
PDU] ! ! ! !
ASS.req ! ! ! !
<#7,LLI ! ! ! !
SAP,INI_ ! ! ! !
REQ_PDU> ! ! ! !
---->! ! ! !
![ASS_REQ_PDU]! ! !
!"start T1 ! ! !
!\CN open: ! ! !
!"activate ! ! !
! FDL LSAP ! ! !
! !**INI_REQ_PDU! !
!(FDL_DATA_ !*ASS_REQ_PDU !(FDL_DATA_ !
! ACK.req) ![SDA_REQ_PDU]! ACK.ind) !
! ]------>!------------>!-------->] !
! [<------!<-----------/! !
!(FDL_DATA_ ![SDA_ACK_PDU]!"start T1 !ASS.ind
! ACK.con) ! !\LLI-LLI !<#9,LLI
! ! ! Context Test!SAP,INI_
! ! ! positive !REQ_PDU>
! ! ! ]---->!---->
! ! !\CN open: !
! ! !"activate !
! ! ! FDL Access !
! ! ! Protection !
! ! ! ! INI.ind
! ! !\T1 expired ! <#9>
! ! ! ! ---->
! ! ![ABT_REQ_PDU]!
ABT.ind ! ! !"start T2 !
<#7,LLI ! ! ! !
SAP,LG, !(FDL_DATA_ !*ABT_REQ_PDU !(FDL_DATA_ !
ID,RC,AD>! ACK.ind) ![SDA_REQ_PDU]! ACK.req !
<----!<------------!<------------!<--------[ !ABT.ind
! !/----------->!-------->] !<#9,LLI
!"stop T1 ![SDA_ACK_PDU]!(FDL_DATA_ !SAP,LG,
ABO.ind ! ! ! ACK.con) !ID,RC,AD>
<#7,LG,ID,! ! ! ]---->!---->
RC,AD> !\CN open: ! !\CN open: !
<---- !"start T2 ! !"deactivate ! ABO.ind
!"deactivate ! ! FDL Access ! <#9,LG,
! FDL LSAP ! ! Protection ! ID,RC,AD>
!"stop T2 ! ! ! ---->
! ! !"stop T2 !
! ! ! !
Figure 54. Master-Master Communication Relationship / Connection
Establishment / Error: T1 expired at the Responder
Page 416
PROFIBUS-Specification-Normative-Parts-6:1997
Copyright by PNO 1997 - all rights reserved
6.3.2.4 Handling of Conflicts
During connection establishment on master-master communication relationships it
is possible that both masters may try to establish the connection at the same
time. This conflict is resolved in the following way:
If the LLI receives an ASS_REQ_PDU of the communication partner before the ex-
pected ASS_RES_PDU or ASS_NRS_PDU resp. is received then LLI shall compare the
own FDL address (parameter Rem_add of the FDL_DATA_ACK.ind) with the FDL address
of the communication partner (parameter Loc_add of the FDL_DATA_ACK.ind). Only
the request to establish a connection of that master with the lower FDL address
is performed. If the communication partner has the lower FDL address, the own
request to establish the connection is rejected with an ABT.ind to the FMS.
Thereafter an ASS.ind is passed to the FMS to signal the communication partner's
request to establish the connection.
The LLI ignores the communication partner's request to establish the connection
if the communication partner has the higher FDL address.
Master/Requester Bus Master/Requester
FDL Address 3 FDL Address 7
FMS ! LLI ! ! LLI ! FMS
! ! ! !
ASS.req ! ! ! ! ASS.req
<#3> ! ! [ASS_REQ_PDU] ! ! <#5>
------------------->!----- =====!<====================
!"Compari- ! - = ! !
! son of ! - = ! !
! FDL ! - = ! !
! Addresses! X ! !
!"reject ! = - ! !
! PDU ! = - ! !
! [<=====!<====== ------>!----->] !
! ! !"Compari- !
! ! ! son of !
! ! ! FDL !
! ! ! Addresses!
! ! ! ! ABT.ind
! ! ! ! <#5>
! ! ! [====>!=========>
! ! ! !
! ! ! ! ASS.ind
! ! ! ! <#5>
! ! ! [---->!--------->
ASS.con ! ! ! ! ASS.res
<#3,R+> ! ! [ASS_RES_PDU] ! ! <#5,R+>
<--------!<---------!<------------------!<---------!<--------
! ! ! !
Figure 55. Conflict Resolution for mutual ASS.req, simplified representation
Page 417
PROFIBUS-Specification-Normative-Parts-6:1997
Copyright by PNO 1997 - all rights reserved
6.3.2.5 Interpretation of the Layer 2 Confirmation Primitive
During the connection establishment phase the parameter L_status of the Layer 2
confirmation primitive (FDL_XXX.con) is interpreted. Certain values of the pa-
rameter L_status (see formsl stste mschine definition) also lead to a connection
release and in some cases to an error message (LLI-FAULT.ind) to the FMA7.
6.3.2.6 Context Test in LLI
Upon receipt of each ASS_REQ_PDU the LLI of the responder checks for the con-
nection to be established that the LLI context of the communication partner (re-
mote context) is compatible with the own LLI context (local context) in the CRL.
This is called LLI-LLI context test.
The local context is assumed to be correctly configured. The same rule shall ap-
ply to the local context between LLI and FMS.
The compatibility of the remote to the local context is shown in the following
matrix:
Table 19. Compatibility of the local to remote Context
+--------+------------------------------------------+
! ! local Context !
! +------------------------------------------+
! remote ! ! ! ! ! ! !
! Context! TYPE ! max ! max ! max ! max ! ACI !
! ! ! SCC ! RCC ! SAC ! RAC ! !
+========+========+=====+=====+=====+=====+=========+
! TYPE ! = ! ! !
+--------+--------+-----+-----+-----+-----+---------+
!max SCC ! ! • ! !
!max RCC ! ! • ! !
!max SAC ! ! • ! !
!max RAC ! ! • ! !
+--------+--------+-----+-----+-----+-----+---------+
! ACI ! ! ! = !
+--------+--------+-----------------------+---------+
! Explanation: !
! ≤ : local value smaller than or equal remote value!
! ≥ : local value larger than or equal remote value !
! = : local value equal to remote value !
+---------------------------------------------------+
6.3.3 Connection Release
The connection release closes an existing logical connection between two commu-
nication partners. A connection may be released in the master or slave by user
initiative, or in error cases by initiative of FMS, FMA7 or LLI.
The connection release is performed using the unconfirmed LLI service Abort
(ABT). A released connection shall be established again using the LLI service
Associate (Ass) before it may be used again for data transfer. If a connection
is in the state "CLOSED" (released), all LLI service requests with exception of
the Associate service are rejected locally with an ABT.ind. All received PDUs
from the remote station with exception of the ASS_REQ_PDU or ABT_REQ_PDU resp.
are rejected with an ABT_REQ_PDU in this state.
If the FMS user wishes to release an existing connection it passes the request
to release the connection (Abort.req) to the FMS. If the FMA7 user wishes to re-
lease an existing connection it passes the request to release the connection
(FMA7-Abort.req) to FMA7. FMS and FMA7 pass the request to release the connec-
tion of their users with an ABT.req service primitive to LLI.
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Copyright by PNO 1997 - all rights reserved
If the local FMS detects errors it passes an Abort.ind to the user and the serv-
ice primitive ABT.req to LLI.
If the local FMA7 detects errors it passes an FMA7-Abort.ind to the user and the
service primitive ABT.req to LLI.
If the local LLI detects errors (e.g. reaction of the LLI connection) it passes
an ABT.ind to the LLI user. The LLI user passes this ABT.ind to the user.
In all cases the LLI of the requester starts the monitoring of connection re-
lease (T2, see connection release definition) and generates an ABT_REQ_PDU. The
LLI enters the reason for the connection release into the fields ID, RC and AD.
The LLI passes the ABT_REQ_PDU to Layer 2 for transmission to the remote commu-
nication partner. After transmission the connection is in the state "CLOSED"
(released). In the case of an open connection in the responder (Connection At-
tribute = "O") the LLI shall stop the access protection for the assigned LSAP
after the connection release. Thereafter the access for all remote partners is
possible again. In the case of an open connection in the requester (Connection
Attribute = "I") the LLI shall deactivate the assigned LSAP after the connection
release.
After the receipt of an ABT_REQ_PDU the LLI of the receiver performs a local
connection release. If local actions of Layer 2 are necessary for this connec-
tion release (e.g. deactivation of an LSAP), then the LLI starts the monitoring
of connection release.
The reason for the connection release is found in the fields ID, RC and AD of
the ABT_REQ_PDU and is passed to the LLI user with the ABT.ind. The FMS passes
this ABT.ind to the user. Thereafter the connection is in the state "CLOSED"
(released). In the case of an open connection in the responder (Connection At-
tribute = "O") the LLI shall stop the access protection for the assigned LSAP
after the connection release. In the case of an open connection in the requester
(Connection Attribute = "I") the LLI shall deactivate the assigned LSAP after
the connection release and thus re-store the initial state for a new request to
establish a connection. Then the monitoring of connection release is stopped if
necessary.
6.3.3.1 Monitoring of Connection Release
For time monitoring of connection release the timer T2 is used. It is connection
specific and mandatory for master and slave devices. The interval for monitoring
connection release is configured in the header of the LLI CRL for all connec-
tions.
In the requester the timer T2 controls the sending of the ABT_REQ_PDU. The timer
T2 is started before the ABT_REQ_PDU is passed to Layer 2 and is stopped after
receiving the Layer 2 confirmation for sending (FDL_XXX.con/FDL_XXX.ind) and af-
ter the termination of all local actions.
In the receiver of an ABT_REQ_PDU the timer T2 controls the connection release
if local actions in Layer 2 (e.g. stopping of Layer 2 polling) or in FMA1/2
(e.g. deactivation of LSAPs) are necessary. The timer T2 is started upon receipt
of the ABT_REQ_PDU and is stopped after termination of all local actions.
If the timer T2 expires the connection release is stopped and the connection
changes into the state "CLOSED". If a local Layer 2 error has occurred, then the
FMA7 is informed additionally.
6.3.3.2 Abort for Master-Slave Communication Relationships
For master-slave communication relationships the master as well as the slave may
take the initiative for connection release. Besides the general rules which are
described in connection release the following specific rules for this communica-
tion relationship are valid.
Page 419
PROFIBUS-Specification-Normative-Parts-6:1997
Copyright by PNO 1997 - all rights reserved
The Abort service (ABT) of the LLI is mapped onto the cyclic Layer 2 service
CSRD.
If the Layer 2 polling to the assigned slave (Rem_add/DSAP) is locked in the
master of a connection for Acyclic Data Transfer with no Slave Initiative, the
LLI shall start the polling for the transmission of the ABT_REQ_PDU. Thereby the
Layer 2 service primitive FDL_CYC_POLL_ENTRY.req with parameter Marker = "un-
lock" is used. If the ABT_REQ_PDU has been transmitted or timer T2 expires, then
the LLI stops the polling to the assigned slave for all master-slave connec-
tions. Thereby the Layer 2 service primitive FDL_CYC_POLL_ENTRY.req with parame-
ter Marker = "lock" is used.
If the master receives an ABT_REQ_PDU then the LLI shall stop the Layer 2 poll-
ing to the assigned slave.
The transmission of the ABT_REQ_PDU from the slave to the master is only guaran-
teed if the slave is still being polled by the master's CSRD service.
EXAMPLE: The following sequence charts (see the following five figures) show ex-
amples of possible connection release sequences.
Page 420
PROFIBUS-Specification-Normative-Parts-6:1997
Copyright by PNO 1997 - all rights reserved
Master/Requester . Slave/Receiver
.
FMA7/ . FMA7/
User!FMS LLI FDL BUS FDL LLI FMS !User
=====!====!=============!======.======!=============!====!=====
ABO.req ! ! ! !
<#7> ! ! ! !
----> ! ! ! !
ABT.req ! ! ! !
<#7,LLI ! ! ! !
SAP,ID,! ! ! !
RC,AD> ![ABT_REQ_PDU]! ! !
---->!"start T2 ! ! !
!(FDL_SEND_ ! ! !
! UPDATE.req) ! ! !
! ]------->!--) ! !
! [<-------!--) ! !
!(FDL_SEND_ ! ! !
! UPDATE.con) ! ! !
! ! ! !
!\PEE = false:! ! !
!"enable ! ! !
! Polling ! ! !
! ! ! !
!(FDL_CYC_POLL! ! !
! _ENTRY.req) ! ! !
! ]------>!--) ! !
! [<------!--) ! !
!(FDL_CYC_POLL! ! !ABT.ind
! _ENTRY.con) ! ! !<#9,LLI
! ! ! !SAP, LG,
! !*ABT_REQ_PDU !(FDL_DATA_ !ID,RC,
! ![SRD_REQ_PDU]! REPLY.ind) !AD>
! ! ]------->!------------>!---->
! [<------!<-----------/! !
!(FDL_CYC_DATA![SRD_RES_PDU]! ! ABO.ind
! _REPLY.con) !*Data/no Data! ! <#9,LG,
! ! ! ! ID,RC,
!"ignore Data ! !\CN open: ! AD>
! ! !"start T2 ! ------>
! ! !"deactivate !
!"disable ! ! FDL Access !
! Polling ! ! Protection !
!(FDL_CYC_POLL! !"stop T2 !
! _ENTRY.req) ! ! !
! ]------>!--) ! !
! [<------!--) ! !
!(FDL_CYC_POLL! ! !
! _ENTRY.con) ! ! !
! ! ! !
!"stop T2 ! ! !
! ! ! !
Figure 56. Master-Slave Communication Relationship / Connection for Acyclic
Data Transfer with no Slave Initiative / Connection Release by the
User of the Master