LORIA – Laboratoire Lorrain de Recherche en Informatique et ses Applications

Jean-Pierre Thomesse the fieldbus technology le 16 Janvier 2004 1

LORIA – Laboratoire Lorrain de Recherche en Informatique et ses Applications

Jean-Pierre ThomesseProfesseur INPL

real-time networks:

the fieldbus technology


Who’s whoWho’s who

EthernetWorldFIP TTP

Profibus-PAIEC 61158

Sercos BacNET

Seriplex

Unitelway

P-NETCSMA-DCR

BatibusEiBUS

Interbus DeviceNet

SDS

ControlNet

CiA

CANOpenProfibus-FMS

FieldBus Foundation

Profibus-DP

DWF ModbusTTP-A

TTP-C

EN 50170EN 50254

TCP-IP

MMS

SNMP

M-PCCN

TASE2CASM

FDDI

ISO 8802.3ISO 8802.4

ISO 8802.5

SinecFIPIO

FIPWay

ControlFIPWDPF JBUS

ASI

PLANMini-MAPLON

EHS

CAN UCA

ICCP

CSMA-CA

CSMA-BA

CSMA-CD

Hart

Digital HartBitbusMAP

TOPF8000

ARINCProfisafe

UIC 556IEC 6375 CIP

M-Bus

WITBUS SycowayGENIUSVAN

OPTOBUSEuridisJ1850

LocaFIP

SwiftNetBluetooth

UWB

WiFi

IEEE 802.11

FireWire

HSE

ISIbus

Switched Ethernet

TOP

LINKSU

P1118

MIL 1553B

Sensoplex

IEC 955

Proway

IEEE 1394

IEC 61804IEC 61784

IEC 61 499EN 50 325

IEC 870-5

IEC 61 375-1

ISO 11519IEC 62026

EN 50 295FlexRay

Anubis FTT-CAN

TT-CAN


contentscontents history

– the industrial networks– the birth of fieldbus

fieldbus DLLs and MACs TCCA: real time to OSI-ISO IEC 61158 DLL features

– buffers and queues– Link Active Scheduling– timeliness attributes

application layer– application relationships– coherences and consistencies

conclusion: standards and lack of standard


before networksbefore networks

SA

Set Point

operator

SA

Set Point

SA

Set Point

SA

Set Point

operatoroperatoroperator


before networksbefore networks

SA

Set Point

operators

SA

Set Point

SA

Set Point

SA

Set Point

optimisation


first networksfirst networks

SA SA SA SA

optimizationmonitoring, control MODBUS

WDPF

and in France

FACTOR

GIXINet, LAC


context - possibilitiescontext - possibilities

technology capabilities– OSI - ISO model (reliability, QoS…)– LAN development– MACs “war”– microelectronics development


context context

functional end-users needs– needs for standardization– MAP - TOP projects– CIM concept and architectures– wiring simplification– instrumentation dedicated O.S.


CIM architectureCIM architecture

instrumentation

machine

cell

plant

Inc

enterprise management

factory control

cell control

machine

instrumentation

TOP

MAP

miniMAP

fieldbus


first networksfirst networks

SA SA SA SA

optimizationmonitoring, control

FIELDBUS


fieldbusfieldbus

connection of field devices and of field controllers– sensors, actuators, drives controllers, PLCs…

real time communication system based on– a layered structure– services and various qualities of service

system considerations– simplification of wiring– spinal column of distributed real time systems

fieldbuses proliferation– lack of standardization– multiple various domains of application


application domainsapplication domains

continuous process control discrete part manufacturing building automation car, trains… utilities networks control transportation systems (railways, highways…)


the birth of fieldbusthe birth of fieldbus

1982 FIP (Factory Instrumentation Protocol) objectives:

– a network for the connection of sensors and actuators

– a network for the development of the smart instrumentation

– a network for the development of distributed automation

– a standard: the “CP/M” of the instrumentation !


the birth of fieldbusthe birth of fieldbus

1984 FIP “white book”– improvement of distributed applications– independence of locations (addresses)– same view of the system by all the stations– coherence of parallel actions– simultaneity of actions, of events– priority to the identified and periodic traffic









periodic trafficperiodic traffic

F

E

D

C

B

A A

D

C

A

D

C

A

D

C

AA

E

B

A

F

E

D

C

B

A A

D

C

A

D

C

A

D

C

AA

E

B

A


fieldbus messagesfieldbus messages

application exchanges

messagesidentified data

real time

periodic

real time

periodic

aperiodic

not real time

on event

(management)

not real time

on event


IEC - ISA fieldbusIEC - ISA fieldbus

requirements (1985-1987)– two networks H1 and H2 (HSE?)– environment constraints (EMC, IS, PD…)– real time : periodic traffic– not real time : random traffic without constraints– time constraints

maximum response time average frequency

and later timeliness attributes time coherence space-time consistency


fieldbus trafficfieldbus traffic

periodic traffic

decentralizedcentralized

tokenTDMA polling CSMATTP

SERCOS

INTERBUS

CONTROLNET

WORLDFIP

PROFIBUS-DP

PROFIBUS-PA

FF

P-NET

PROFIBUS FMS

+

polling

CAN

DEVICENET

SDS

CANOPEN

LON



aperiodic traffic

decentralized

as periodicperiodic server

when token

time slot in each frame

special frame on demand

CSMA



aperiodic traffic

decentralizedperiodic server

when token

CONTROLNET

P-NET

INTERBUS WORLDFIP

PROFIBUS-PA

FF

CSMA

CAN

SDS

DeviceNet


WorldFIP - 1WorldFIP - 1

75

Speed

Local Write

Speed“copy”

Local Read

52Speed“copy”

Local Read

Speed

Bus arbitrator

52



75

Speed

Local Write

Speed“copy”

Local Read

52Speed“copy”

Local Read

Speed

Bus arbitrator

Speed

52



75

Speed

Local Write

Speed“copy”

Local Read

Speed“copy”

Local Read

Speed

Bus arbitrator

v(Speed)=75



75

Speed

Local Write

Speed“copy”

Local Read

Speed“copy”

Local Read

Speed

Bus arbitrator

75 75



VAR1

VAR2

VAR4

VAR7

VARX

…

VAR5

VAR1

VAR5

VAR7

VARX

VAR5

POLLING TABLE PERIODIC TRAFFIC

STATIC

APERIODIC TRAFFIC

DYNAMIC


Profibus - 1Profibus - 1

M1 M2 M3 M4

Slave3Slave2Slave1Slave4 Slave5

TOKEN passing

POLLING

ANSWER


Profibus -2Profibus -2

role of a Profibus master– receive the token– perform high priority messages first– perform the exchanges specified in the Poll List– perform low priority messages– perform station registration (live list)– send the token


ControlNet - 1ControlNet - 1

based on a fixed repetitive time cycle – Network Update Time (NUT)– close synchronism– each node - a clock synchronised to the NUT– access to the medium in sequential order based

on the MAC ID of the node– implicit token passing

at the end of a frame, comparison of the received MAC ID +1 with the own address



Scheduled part

NUT iNUT I+1

Unscheduled part Guard Band

station K

station K+1



in a NUT, three time windows– scheduled– unscheduled– Guard Band

one MAC Frame by node in scheduled part predictable and deterministic manner Round Robin in the unscheduled part


Interbus - 1Interbus - 1

Station Kperiodic data

Station Kaperiodic

data

start

K+1

K+2









the birth of TCCA (ISO)the birth of TCCA (ISO)

MAP project– no real time– mini-MAP experiments for real time– real time requirements (from EMUG - 1989)

difficulties of IEC Fieldbus standardization


real time requirements real time requirements (from EMUG)(from EMUG)

user designated priorities ==>OSI stack problems predictable or “boundable” delays and behavior user selection of the error recovery strategy congestion recovery appropriate to messaging traffic support multicast communications


real time requirements real time requirements (from EMUG)(from EMUG)

means of synchronizing the sense of distributed time support communications redundancy and

redundancy in (of) controlling entities inexpensive network connection inter-work with informational network security mechanisms, privacy, authentification and

minimization of denial-of-service


the OSI modelthe OSI model

OSI-ISO model and real time ? OSI model is an organization of communication functions OSI layers 1 and 2 : basic transport (simple network) OSI layers 3 and 4 : extended transport (complex network) OSI layers 5, 6 and 7 : service enhancements, user oriented

– layer 5: synchronization

– layer 6: languages and dialects - transfer syntax

– layer 7: messaging services - standards languages for different application-specific needs


the modelthe model

Physical layer

Time-Critical OSI data link layer

OSI network layer

OSI transportlayer

OSI Application layerFieldbus

application layer

OSI presentation layer

OSI session layer

Fieldbus presentation layer

omitted

omitted


Time-Critical data link layerTime-Critical data link layer

IEC 61158 - type 1 as the model issued from

– ISA SP50 - 1990-359E: data link service definition– ISA SP50 - 1990-360C: data link protocol definition

and later from– IEC 65C/160 CDV (1996): data link service definition– IEC 65C/161 CDV (1996): data link protocol definition




fieldbus DLLs TCCA: real time to OSI-ISO IEC 61158 DLL features





data link layerdata link layer

provided features– independence from the physical layer– transparency of transferred information– reliability and Qualities of Service– addressing– scheduling– common time sense and timeliness– storages (Queues and Buffers)


buffers and queuesbuffers and queues

14 1212

16 1212

16 1616

121416

161412


storagestorage

types of storage– queues– retentive buffers– non retentive buffers

general rules– sender by queue

receiver in queue

– sender by buffer receiver in queue receiver in buffer









arbitratorarbitrator

NODE

NODE

NODE NODENODE

NODE

NODE

NODE

NODE

NODENODE

NODE

NODE

NODE

NODEARBITRATOR

DISTRIBUTE

COMPEL


tokentoken

NODE

NODE

NODE

NODE

NODE

NODE

NODE

NODE

NODE

NODENODE

NODE

NODE

NODE

NODE

TOKEN

Message

Message

Reply

TOKEN


L.A.S.L.A.S.

NODE

NODE

NODE NODENODE

NODE

NODE

NODE

NODE

NODENODE

NODE

NODE

NODE

NODEL.A.S.

DISTRIBUTE

COMPEL


L.A.S.L.A.S.

NODE

NODE

NODE NODENODE

NODE

NODE

NODE

NODE

NODENODE

NODE

NODE

NODE

NODEL.A.S.

TOKEN

MSG

MSG

REPLY


L.A.S.L.A.S.

NODE

NODE

NODE NODENODE

NODE

NODE

NODE

NODE

NODENODE

NODE

NODE

NODE

NODEL.A.S.

TOKEN









timelinesstimeliness

timeliness for data transfer between buffers buffers can decouple

– data production – data transfer – data consumption

data age may be unknown



resident assessment based upon the length of time that a

data unit has been resident in a buffer

Residence Time

Write-date Read-date End of timewindow



update assessment based upon the time interval

between a synchronizing event and the moment the buffer is written

Update-Time

Synchro-date Writing-date End of timewindow



synchronous assessment based upon the time intervals

and timing relationships between – a synchronizing event– the moment when the buffer is written– the moment the buffer is read

Synchro-date Writing-date End of timewindow

Read-date









application relationshipsapplication relationships

client - server– confirmed– unconfirmed

publisher - subscriber– pull publisher– push publisher


client - serverclient - server

classical model

application

layer

clientserver

XXX-Request

XXX-ConfirmationXXX-Response

XXX-Indication



unusual modelapplication

layer client

server

XXX-RequestXXX-Indication



unusual modelapplication

layer client

server

XXX-Request

YYY-Indication

YYY-Request

XXX-Indication


publisher - subscriberpublisher - subscriber

“pull” model

subscriber

subscriber

subscriber

pullpublisher

Request

Response

publishing manager


publisher - subscriberpublisher - subscriber

“push” modelpushsubscriber

subscriber

subscriber

subscriber

pushpublisher

subscribing request

published information

response


time coherencetime coherence

time coherence of actions, of events simultaneity of events occurrences in a given time window time coherence of

– productions– consumptions– other actions


time coherencetime coherence

control of time coherence– data received indication – allows, in multi peer connections, the

synchronization of subscribers usable to control any actions simultaneity verification of time coherence

– by timeliness attributes


space - time consistencyspace - time consistency

need “reliable broadcasting” management of lists of variables (copies)

– produced by different publishers– consumed by several subscribers

verification and correction to obtain identical lists by the subscribers

kind of global acknowledgement for different transmitters hypothesis:

– two remote copies are considered identical if they are received without error and correct timeliness attributes


space - time consistencyspace - time consistency

NODE

NODE

NODE NODENODE

NODE

NODE 7

NODE

NODE 9

NODENODE 8

NODE

NODE

NODE 6

NODEL.A.S.

COMPEL (A)

value(A)

value(A)

value(A)

value(A)COMPEL (B)

DISTRIBUTE B value(B)

value(B)

value(B)

value(B)

DISTRIBUTE A

COMPEL L6

DISTRIBUTE L6

L6=OK

L8=OK L9=OK

L7=not OK, B







conclusion


schedulingscheduling

three types of networks– 1st

periodic traffic, prescheduled at the configuration time sporadic traffic, prescheduled at the configuration time

– 2nd periodic traffic, prescheduled at the configuration time sporadic traffic, dynamically managed

– 3rd periodic and sporadic traffics dynamically managed


profilesprofiles

how many layers ?

which layers ?

which protocols ?

stack modelling ?

which models ?

which objectives ?

wireless, fibre optic ?

TDMA, CSMA, token ?

LLC1, LLC3, …??

C/S, P/C, P/S…

TCP/IP,others ?


conclusionconclusion

real time networks– industrial networks

– afterwards, in car, in trains… in building automation in Internet

– but also now, for all devices mobility ambient intelligence

– Internet


conclusionconclusion

real time =

to express the constraints + to meet the constraints

+ behaviour controlled by the user


LORIA – Laboratoire Lorrain de Recherche en Informatique et ses Applications

Jean-Pierre ThomesseProfesseur INPL

real-time networks:

the fieldbus technology

Documents

LORIA – Laboratoire Lorrain de Recherche en Informatique et ses Applications