Wilamowski B.M., Irwin J.D. The Industrial Electronics Handbook. Second Edition: Industrial Communication Systems

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40-10 Industrial Communication Systems

which.communication.can.be.implemented.exibly..It.only.has.to.be.ensured.that.all.IRT.frames.can.be.sent.

wit

hin

.the.“or

ange

.int

erval.”

. e.syn

chronized

.“se

.cyc

le”

.caus

.all.nod

.par

ticipating

.in.IRT.com

mu-

nication

.to.sta

.tra

nsmitting

.I/O.data.at.the.sta

.of.the.“or

ange

.int

erval.”

.As.a.res

ult,

.all.pos

sible

.wai

.tim

are.red

uced

.to.a.min

imum

.(sa

.as.in.uns

ynchronized

.com

munication),

.whe

reas

.the.I/O.tra

c

.is.sec

ured

aga

inst

.oth

.data.tra

c.

. e.data.fra

mes

.are.tra

nsmitted

.to.the.end.nod

.via.the.res

pective

.des

tination

.por

sol

ely

.on.the.basi

.of.the

.MAC.add

ress

.(an

.cor

responding

.Fra

me_ID).

. is.ena

bles

.a.ver

.ex

ible

.met

hod

of.com

munication

.tha

.is.not.sub

ject

.to.any.spe

cial

.rul

es.

.Cha

nges

.in.the.pla

.top

ology

.hav

.no.ee

.her

How

ever,

.base

.on.the.con

cept,

.the.enh

anced

.ex

ibility

.and.res

ulting

.ease.of.adap

tability

.of.a.sys

tem

.is.mad

pos

sible

.at.the.exp

ense

.of.inc

omplete

.opt

imization

.of.the.ban

dwidth

.uti

lization

.beca

use

.a.sma

.res

erve

.is.

pro

vided

.for.in.the.“or

ange

.int

erval.”

. is.ens

ures

.tha

.all.fra

mes

.hav

.bee

.sen

.Fra

mes

.wit

hin

.the.“or

ange

int

erval”

.can.be.tra

nsmitted

.wit

.or.wit

hout

.VLA

.tag

40.3.2 Communication Based on rt_CLaSS_3 (red Interval)

In.this.case,.the.communication.in.the.“red.interval”.is.based.on.a.schedule.congured.in.advance.(dur-

ing

.eng

ineering

.pha

se),

.i.e

.in.add

ition

.to.the.inf

ormation

.for.the.end.nod

es,

.the.net

work

.com

ponents

loc

ated

.in.bet

ween

.req

uire

.inf

ormation

.de

ning

.the.for

warding

.of.fra

mes.

.Fra

mes

.are.for

warded

.bas

exc

lusively

.on.the.pla

nning

.alg

orithm

.de

ned

.in.IEC.611

58.

.As.a.res

ult

.of.pla

nning,

.an.Ethe

rnet

.con

troller

.(or.mor

.pre

cisely,

.the.int

egrated

.swi

tch

.in.an.Ethe

rnet

.con

troller)

.kno

.exa

ctly

.whi

.fra

arr

ives

.at.whi

.por

.and.whe

.it.mus

.be.for

warded

.to.whe

re.

. is.ena

bles

.a.ver

.hig

.uti

lization

of.the.ban

dwidth

.ava

ilable.

.If.a.sys

tem

.req

uires

.RT_

CLASS_3

.com

munication,

.the.bus.cyc

.mus

.be.

div

ided

.into.a.“re

.int

erval”

.and.a.UDP

/IP

.par

.(gr

een

.int

erval)

.dur

ing

.eng

ineering.

.Her

.the.tim

ing

and.len

gth

.of.eac

.fra

.to.be.sen

.is.spe

cied

.on.a.por

t-by-port

.basi

. e.pla

.topo

logy,

.the.res

pective

fra

.len

gth,

.and.the.cab

.len

gths

.bet

ween

.the.ind

ividual

.nod

.are.cri

tical

.fac

tors

.in.the.tim

ing

.for.

the.pur

pose

.of.its.opti

mal

.uti

lization.

.If.the.sys

tem

.is.cha

nged,

.the.pla

nning

.alg

orithm

.mus

.the

refore

be.rep

eated.

.Dat

.tra

nsmission

.in.the.IRT.por

tion

.is.alw

ays

.sch

eduled.

. e.“sc

hedule”

.is.gea

red

.onl

to.the.seq

uence

.of.arr

iving

.fra

mes,

.whi

.is.det

ermined

.by.the

.Fra

me_ID

.and.the.fra

.len

gth.

. e.

tim

e-controlled

.pro

cessing

.of.jobs.wit

hin

.the.“re

.int

erval”

.aid

.in.eli

minating

.the.na

.sou

rces

.of.ina

curacies.

.Sin

.RT_

CLASS_3

.com

munication

.is.ori

ented

.onl

.on.the.basi

.of.tim

ing,

.the.thr

oughput

tim

.of.dat

.fra

mes

.thr

ough

.a.swi

tch

.are.sign

icantly

.sho

rter.

.Lik

ewise,

.the.per

formance

.in.bra

nched

net

works

.can.be.inc

reased

.by.opti

mized

.use.pla

nning

.of.the.sam

.com

munication

.pat

. e.topo

logy

inf

ormation

.is.sen

.to.the.res

pective

.IO.con

troller

.dur

ing

.sys

tem

.pow

er-up.

.RT_

CLASS_3

.fra

mes

.are.

alw

ays

.se

.wi

thout

.VL

.ta

.sin

.th

.ch

ronological

.po

sition

.is.al

ways

.kn

own.

40.3.3 Cycle Duration and Constrains

 e.maximum.frame.length.in.Ethernet/PROFINET.yields.a.minimum.duration.of.the.“green.interval”.of.

125.μs.(4.×.31.

.μs)..How

ever,

.cer

tain

.rul

.mus

.be.de

ned

.in.ord

.to.car

.out.ec

ient

.dat

.com

munica-

tion

.inv

olving

.di

erent

.RT.cla

sses,

.ens

uring

.tha

.the.timi

.and.the.iso

chronous

.ope

ration

.are.adh

ered

.to.in.

eve

.con

guration.

. e.gen

eral

.rul

.is.tha

.at.lea

.two.TCP

/IP

.fra

mes

.wit

.max

imum

.len

gth

.can.be.sen

per.mill

isecond.

. is.cor

responds

.to.a.tra

nsmission

.tim

.of.app

roximately

.250.μs..For.bus.cyc

les

.<=.500.μs,.

the.rul

.is.red

uced

.to.one.TCP

/IP

.fra

me.

.Fur

thermore,

.the.tra

nsmission

.tim

.of.cyc

lic

.dat

.sho

uld

.not.exc

eed

60%.of.the.bus.cyc

.in.ord

.to.all

.su

cient

.tim

.for.TCP

/IP

.com

munication

.(se

.Fig

ure

.40.

5).

Only

.el

.dev

ices

.tha

.sup

port

.syn

chronization

.mea

sures

.can.par

ticipate

.in.syn

chronized

.com

muni-

cation

.(bu

.syn

chronization).

.Oth

erwise,

.the.tim

ing

.of.the.di

erent

.pha

ses

.can

not

.be.adh

ered

.to..Eac

dev

ice

.has.its.own.upd

ate

.tim

. e.adv

antage

.of.the.dev

ice-granular

.upd

ate

.spe

cication

.is.tha

.the.

ban

dwidth

.can.be.sha

red

.by.fas

.nod

.and.slo

.nod

es.

.As.a.res

ult,

.the.upd

ate

.rat

.is.no.lon

ger

.det

er-

mined

.by.the.tota

.numb

.of.nod

.but.ins

tead

.can.be.ada

pted

.acc

ording

.to.the.app

lication.

.Und

.cer

tain

.con

ditions,

.it.is.pos

sible

.to.hav

.a.mix

ture

.of.iso

chronous

.and.non

isochronous

.app

lications

.in.el

devices.in.one.automation.system..However,.between.two.devices.that.run.isochronously,.only.switches.

wit

.su

pport

.to.is

ochronous

.op

eration

.ca

.be.us

ed.

PROFINET 40-11

40.4 Engineering and Commissioning

 e.PROFINET.support.to.the.system.engineering.is.very.powerful.in.order.to.reduce.the.commission-

ing

.phas

.of.the.netw

ork.

.For.inst

ance,

.the.PROF

INET

.func

tionalities

.of.a.cert

ied

.devi

.are.desc

ribed

in.a.port

able

.le.(the.GSD.le)

.and.netw

ork

.mana

gement

.(add

ressing,

.redu

ndancy,

.etc.

)

.are.incl

uded

in.the.pro

tocol

.sta

ck.

40.4.1 GSD File

 e.functionality.of.a.PROFINET.IO.device.is.always.described.in.a.GSD.le.. is.le.contains.all.data.

that.are.rele

vant

.for.engi

neering

.as.well.as.for.data.exch

ange

.with.the.IO.devi

ce.

.PROF

INET

.IO.devi

ces

can.be.desc

ribed

.using.XML-b

ased

.GSD.. e.desc

ription

.lang

uage

.of.the.GSD.le,.i.e.,.Gene

ric

.Stati

Desc

ription

.Mark

.Lang

uage

.(GSD

ML),

.is.base

.on.inte

rnational

.stan

dards.

.As.the.name.sugg

ests,

the.GSD.le.is.a.lang

uage-independent

.eXten

sible

.Mark

.Lang

uage

.(XML

)

.le..Many.XML.pars

ers

are.curr

ently

.avai

lable

.on.the.mark

.for.inte

rpreting

.XML.les

.Ever

.manu

facturer

.of.a.PROF

INET

IO.devi

.must.supp

.an.asso

ciated

.GSD.le.acco

rding

.to.the.GSDM

.spec

ication.

. is.le.is.test

as.part.of.cert

ication

.test

ing.

.To.desc

ribe

.PROF

INET

.IO.devi

ces,

.PI.prov

ides

.an.XML.sche

.to.each.

manu

facturer.

. is.allo

.a.GSD.le.to.be.crea

ted

.and.test

.easil

. e.need.for.nume

rous

.subs

quent

.inpu

.chec

.is.ther

efore

.omit

ted.

.In.addi

tion,

.the.devi

.mode

.of.PROF

INET

.IO.exhi

bits

.a.

furt

her

.hier

archy

.leve

.for.data.addr

essing

.when.comp

ared

.to.PROF

IBUS.

. us,.e.g.,.addr

essing

.with

a.eld.devi

.(in.PROF

IBUS:

.slot.and.inde

.has.been.expa

nded

.to.incl

ude

.the.iden

tier

.of.a.subs

lot.

In.PROF

INET

.IO,.addr

essing

.with

.a.eld.devi

.can.be.perf

ormed

.with.ner.gran

ularity

.(slo

.and.

subs

lot).

.In.addi

tion,

.this.type.of.addr

essing

.coul

.not.be.desc

ribed

.with.the.GSD.le.for.PROF

IBUS.

To.enab

.syst

.engi

neering,

.the.GSD.les.of.the.eld.devi

ces

.to.be.con

gured

.are.requ

ired.

. e.eld.

devi

.manu

facturer

.is.resp

onsible

.for.supp

lying

.thes

.Duri

.syst

.engi

neering,

.the.con

guring

engi

neer

.joins.toget

her

.the.modu

les/submodules

.den

.in.the.GSD.le.to.map.them.to.the.real.syst

and.to.assig

.them.to.slot

s/subslots.

. e.con

guring

.engi

neer

.con

gures

.the.real.syst

em,

.so.to.spea

symbo

lically

.in.the.eng

ineering

.tool

40.4.2 Device addressing

A.logical.name.is.assigned.to.every.eld.device..It.should.reference.the.function.or.the.installation.

loca

tion

.of.the.devi

.in.the.plan

.and.ulti

mately

.lead.to.assig

nment

.of.an.IP.addr

ess

.duri

.addr

ess

reso

lution.

. e.name.can.alwa

.be.assig

ned

.with.the.DCP.inte

grated

.by.defa

ult

.in.ever

.PROF

INET

.IO.

eld.devi

ce.

.PROF

INET

.prov

ides

.also.the.optio

.for.addr

ess

.sett

ing

.via.DHCP.or.othe

.manu

facturer-

specic

.mech

anisms.

. e.addr

essing

.optio

.supp

orted

.by.an.IO.eld.devi

.are.den

.in.the.GSD.le.

for.the.resp

ective

.devi

ce.

.An.IO.cont

roller

.has.all.the.info

rmation

.need

.for.addr

essing

.the.IO.devi

ces

and.for.data.exch

ange

.aer.all.the.nece

ssary

.info

rmation

.have.been.down

loaded

.by.the.manu

facturer-

specic

.eng

ineering

.tool

Before

.it.can.perf

orm

.data.exch

ange

.with.an.IO.devi

ce,

.the.IO.cont

roller

.must.assig

.the.IO.devi

an.IP.addr

ess

.base

.on.the.devi

.name

. is.must.take.plac

.prio

.to.syst

.powe

r-up

.(“Po

wer

.on”.or.a.

“Res

et”).

. e.IP.addr

ess

.is.assig

ned

.with

.the.same.subn

.using.the.DCP.proto

col

.inte

grated

.by.defa

ult

in.ever

.PROF

INET

.IO.devi

ce.

.An.IO.cont

roller

.alwa

.init

iates

.syst

.powe

r-up

.aer.a.star

tup/restart

base

.on.the.con

guration

.dat

.wit

hout

.any.int

ervention

.by.the.use

40.4.3 System Power-Up

Following.a.“power.on,”.the.following.steps.are.performed.in.the.eld.device:.initializing.the.physi-

cal

.inte

rfaces

.in.an.IO.devi

.in.orde

.to.acco

mmodate

.the.data.tra

.nego

tiating

.the.tran

smis-

sion

.para

meters;

.dete

rmining

.the.degr

.of.expa

nsion

.in.the.eld.devi

.and.comm

unicating

.the.

40-12 Industrial Communication Systems

information.to.the.context.management;.starting.the.exchange.of.the.neighborhood.information;.

address.resolution.on.the.side.of.the.IO.controller;.establishment.of.communication.between.IO.con-

troller

.and.IO.device;.parameterizing.the.submodules.in.the.device.(write.records);.retentive.saving.of.

port.information.to.the.physical.device.(PDev);.completing.and.checking.the.parameterization,.and.

starting.the.data.exchange.

.establish.communication.between.the.higher.level.controller.and.an.IO.device,.the.communica-

tion

.paths.must.be.established.. ese.are.set.up.by.the.IO.controller.during.system.startup.based.on.the.

conguration.data.in.the.engineering.system.. is.species.the.data.exchange.explicitly..As.shown.in.

Figure.40.4,.every.data.exchange.has.an.embedded.“application.relation”.(AR).. is.establishes.a.pre-

cisely

.specied.application.(connection),.i.e.,.the.AR,.between.the.higher.level.controller.(IO.controller.

or.IO.supervisor).and.the.IO.device..Within.the.AR,.“communication.relations”.(CR).specify.the.data.

explicitly..An.IO.device.can.have.multiple.ARs.established.from.various.IO.controllers.

.IO.controller.initiates.setup.of.an.AR.during.system.power-up..As.a.result,.all.data.for.the.device.

modeling,.including.the.general.communication.parameters,.are.downloaded.to.the.IO.device..At.the.

same.time,.the.communication.channels.for.cyclic/acyclic.data.exchange.(IO.data.CR,.record.data.CR),.

alarms.(alarm.CR),.and.multicast.communication.relations.(MCR).are.set.up..CR.for.data.exchange.must.

be.set.up.within.an.AR.. ese.specify.the.explicit.communication.channel.between.a.consumer.and.a.

provider.

40.4.4 Neighborhood and topology Detection

PROFINET.specication.describes.a.method.to.replace.a.device.without.using.an.engineering.tool..

 is.task.is.done.by.means.of.neighborhood.detection.with.the.link.layer.discovery.protocol.(LLDP).

according.to.IEEE.802.1.AB.. is.requires.the.ability.to.determine.the.data.of.neighboring.devices.

on.a.port-by-port.basis.using.LLDP.services.and.to.provide.these.data.to.the.higher.level.controller..

Together,.these.conditions.enable.modeling.of.a.plant.topology.and.convenient.plant.diagnostics.as.

well. as. device.replacement.without.additional.tools.. PROFINET. IO.eld.devices.exchange.existing.

addressing.information.with.connected.neighbor.devices.over.each.switch.port.. e.neighbor.devices.

are.thereby.unambiguously.identied.and.their.physical.location.is.determined.. e.LLDP.protocol.is.

implemented.in.soware.and.therefore.requires.no.special.hardware.support..LLDP.is.independent.of.

the.network.structure.(line,.star,.etc.)..Automation.systems.can.be.congured.with.a.line,.star,.or.tree.

structure..For.this.reason,.it.is.important.to.know.which.eld.devices.are.connected.to.which.switch.

port.and.the.identity.of.the.respective.port.neighbor.. e.higher.level.controller.can.then.reproduce.the.

plant.topology.accordingly..In.addition,.if.a.eld.device.fails,.it.is.possible.to.check.whether.the.replace-

ment

.device.has.been.reconnected.in.the.proper.position.

IO Data CR

- Process data

Record data CR

- Conguration

- Parametrization

Alarm CR

- Real-time alarm

PROFINET

IO-

controller

PROFINET

IO-

device

FIGURE 40.4 Data. communication. in. PROFINET. IO. is. encapsulated. in. “application. and. communication.

relations.”

PROFINET 40-13

40.4.5 redundancy

 e.goal.of.redundancy.in.automation.systems.is.to.increase.the.system.availability.signicantly,.thus.a.

redundancy.manager.(RM).and.several.clients.should.be.used.to.assure.the.correct.operation.in.this.cases.

.media.redundancy.protocol.(MRP),.according.to.IEC.61158.and.IEC.61784,.describes.PROFINET.

redundancy.(for.TCP/IP.and.RT.frames).with.a.typical.reconguring.time.of.communication.paths.aer.

a.fault.of.less.than.200.ms.. e.MRP.operates.with.a.physical.ring.structure.where.the.RM.is.the.coordina-

tor.

. e.task.of.an.RM.is.to.check.the.functional.capability.of.the.congured.ring.structure.. is.is.done.by.

sending.out.cyclic.test.frames:.as.long.as.the.ring.structure.is.intact,.it.receives.all.the.test.frames.again.aer.

one.circulation.through.the.ring.. e.architecture.allows.an.RM.to.prevent.standard.frames.from.circulating.

and.to.convert.a.physical.ring.structure.into.a.“logical”.line.structure.. e.RM.must.communicate.changes.

in.the.ring.to.all.clients.involved.(switches.as.so-called.passers).through.special.“change.in.topology”.frames.

.principle,.even.in.PROFINET.IO.redundant.installations,.the.same.previously.described.data.trans-

mission

.mechanisms.are.used.. e.only.dierence.is.the.communication.path.used.to.transmit.the.frames.

(UDP/IP.and.RT.frames).. ese.frames.are.only.transmitted.via.the.“healthy”.channel.(single.channel).

that.looks.like.a.line.structure..A.redundancy.client.(RC).is.a.switch.that.acts.only.as.a.“passer”.of.frames.

and.generally.does.not.assume.an.active.role..It.must.have.two.switch.ports.in.order.to.connect.to.other.cli-

ents

.or.the.RM.in.a.single.ring..In.PROFINET.IO,.only.“managed.switches”.that.support.MRP.are.used.for.

implementing.media.redundancy..Redundant.switches.can.be.congured,.e.g.,.via.SNMP.or.Web.services.

.media.redundancy.for.real-time.(MRRT).protocol.dened.in.IEC.61158.describes.the.handling.of.

RT.frames.of.RT_CLASS_1.and.RT_CLASS_2.for.redundancy.operation..Operation.of.MRP.is.always.

a.prerequisite.for.operation.of.MRRT..IEC.61784.describes.the.procedure.for.using.the.MRRT.protocol..

With.RT.communication,.the.MRRT.protocol.enables.a.virtually.smooth.switchover.of.communica-

tion

.paths.if.a.fault.occurs.. is.is.accomplished.by.redundant.transmission.of.RT.frames.(i.e.,.via.two.

channels).if.the.destination.port.is.designed.as.a.redundant.port.(see.Figure.40.5)..On.the.receiving.side,.

two.RT.frames.always.arrive,.provided.the.redundant.transmission.is.error-free..Only.the.rst.frame.to.

arrive.is.forwarded.to.the.application..Also.in.this.case,.the.RM.must.check.the.functional.capability.of.

the.system.by.means.of.test.frames.

Station 1

Managed switch

Redundant ports

Station

Process data

Test frame

Destination

Source

Comparison

old/new data

FIGURE 40.5 Media.redundancy.with.MRP.increases.the.plant.availability.

40-14 Industrial Communication Systems

IEC. 61158.describes. the. redundancy. concept. for. RT_CLASS_3. frames.as. “media. redundancy. for.

plan

ned

.dupl

ication.”

.IEC.6178

.descr

ibes

.the.use.of.redun

dancy

.clas

.3.for.RT_C

LASS_3

.comm

unica-

tion

.with.smoo

.swit

chover

.of.comm

unication

.path

.if.a.faul

.occur

.Duri

.syst

.powe

r-up,

.the.IO.

cont

roller

.load

.the.data.of.the.comm

unication

.path

.for.both.comm

unication

.chan

nels

.(dir

ections)

.in.a.

comm

unication

.ring.to.the.indi

vidual

.node

. us,.it.is.unim

portant

.whic

.node.fail

.becau

.the.load

“sched

ule”

.for.both.path

.is.avail

able

.in.the.eld.devi

ces.

.Load

ing

.of.the.“sched

ule”

.alon

.is.suc

ient

.to.

excl

ude

.fram

.from.circ

ulating

.in.this.varia

nt,

.becau

.the.dest

ination

.port

.are.expl

icitly

.den

ed.

40.5 Integration of Fieldbus Systems and Web applications

PROFINET. species.a. model.for.integrating. existing.PROFIBUS.and.other.eldbus.systems.such.as.

INTE

RBUS

.and.Devi

ceNet.

. is.mean

.that.any.comb

ination

.of.eld

bus

.and.Ethe

rnet-based

.subs

ystems

can.be.con

gured

.in.a.simp

.way.. e.foll

owing

.cons

trains

.are.take

.into.cons

ideration:

.the.plan

.oper

tor

.woul

.like.the.abil

ity

.to.easi

.inte

grate

.his.exis

ting

.inst

allations

.into.a.newl

.inst

alled

.PROF

INET

syst

em;

.the.plan

.and.mach

ine

.manu

facturer

.woul

.like.the.abil

ity

.to.use.the.well

-proven

.devi

ces

.it.is.

fami

liar

.with.for.PROF

INET

.auto

mation

.proj

ects,

.as.well

.with

out

.the.need.for.any.modi

cations;

.the.

devi

.manu

facturer

.woul

.like.the.abil

ity

.to.inte

grate

.its.exis

ting

.eld.devi

ces

.into.PROF

INET

.syst

ems

with

out

.expe

nding

.any.eor

.for.modi

cations.

.Fiel

dbus

.solut

ions

.can.be.easi

.and.seaml

essly

.inte

grated

into.a.PROF

INET

.syst

.usin

.prox

ies

.and.gate

ways.

.Anyw

ay,

.the.more.powe

rful

.way.is.usin

.a.prox

40.5.1 Integration via Proxy

In.simplest.terms,.a.proxy.is.a.representative.for.a.lower-level.eldbus.system..In.PROFINET,.a.proxy.rep-

resents

.a.eld

bus

.(e.g.

.PROF

IBUS,

.Inte

rbus,

.Foun

dation

.Fiel

dbus,

.Devi

ceNet).

.As.a.resu

lt,

.the.advan

tages

of.eld

buses,

.such.as.high.dyna

mic

.resp

onse,

.pinp

oint

.diag

nostics,

.and.auto

matic

.syst

.con

guration

with

out

.setti

ngs

.on.devi

ces,

.can.be.util

ized

.in.the.PROF

INET

.worl

.More

over

.with.the.prox

.devi

ces

and.sowa

.tool

.are.also.supp

orted

.in.the.accus

tomed

.mann

.and.inte

grated

.into.the.hand

ling

.of.the.

PROF

INET

.syst

em.

. e.prox

.coor

dinates

.the.Ethe

rnet

.data.tra

.and.the.eld

bus-specic

.data.traf

c.

.For.inst

ance,

.a.PROF

INET/PROFIBUS

.prox

.(on.the.Ethe

rnet

.side

)

.repr

esents

.one.or.more.eld

bus

devi

ces.

. is.prox

.ensu

res

.tran

sparent

.impl

ementation

.of.comm

unication

.(no.tunn

eling

.of.prot

ocols)

betw

een

.netw

orks.

.For.exam

ple,

.it.forw

ards

.the.cycl

.data.comi

.from.the.Ethe

rnet

.to.the.eld

bus

devi

ces

.in.a.tran

sparent

.mann

er.

.On.the.PROF

IBUS

.DP.side

.the.prox

.work

.as.a.PROF

IBUS

.mast

that.exch

anges

.data.with.PROF

IBUS

.node

.At.the.same.time

.it.is.an.Ethe

rnet

.node.with.Ethe

rnet-based

PROF

INET

.comm

unication.

.this.proc

ess,

.the.Ether

net

.comm

unication

.is.alre

ady

.den

.by.the.avai

lable

.sow

are.

.Only.the.

init

ialization

.of.the.proc

ess

.data.prev

iously

.prov

ided

.from.the.lowe

.leve

.eld

bus

.to.PROF

INET

.stil

has.to.be.ensu

red.

.As.a.resu

.of.this.conc

ept,

.eld

buses

.of.any.type.can.be.inte

grated

.into.PROF

INET

with.mini

mal

.eor

.wher

eby

.a.prox

.is.used.to.repr

esent

.the.lowe

.leve

.bus.syst

em.

.For.inst

ance,

.prox

ies

.can.be.imp

lemented

.as.PLC

.or.PC-b

ased

.con

trollers.

40.5.2 Web Integration

 e.PROFINET.Web.integration.was.designed.mainly.for.commissioning.and.diagnostics..Possible.

appl

ications

.for.Web.inte

gration

.incl

ude:

.test

ing

.and.comm

issioning

.of.the.netw

ork,

.over

view

.of.devi

data.(PRO

FINET

.IO),.and.devi

.diag

nostics

.and.syst

em/device

.docu

mentation.

. e.basic.comp

onent

of.Web.inte

gration

.is.the.Web.serv

er.

. is.mean

.that.even.a.simpl

.PROF

INET

.devi

ces

.with.Web.

inte

gration

.optio

.is.equi

pped

.with.an.“embe

dded

.Web.serv

er.”

. e.indi

vidual

.func

tions

.can.be.impl

mented

.depe

nding

.on.the.perf

ormance

.capa

bility

.of.the.devi

ce.

. is.allo

.solu

tions

.to.be.custo

mized

to.eac

.use.cas

PROFINET 40-15

acronyms

AR. Application.relation

. Com

munication

.re

lations

DCP

. Dis

covery

.an

.co

nguration

.pr

otocol

DHCP

. Dyn

amic

.ho

.co

nguration

.pr

otocol

IRT

. Iso

chronous

.re

al-time

.co

mmunication

LLDP

. Lin

.la

yer

.di

scovery

.pr

otocol

MRP

. Med

.re

dundancy

.pr

otocol

MRRT

. Med

.re

dundancy

.fo

.re

al-time

. PRO

FIBUS

.In

ternational

. Rea

l-time

.co

mmunication

Bibliography

. 1.. International.Electrotechnical.Commission,.IEC.61158..Digital.data.communications.for.measure-

ment

.and.cont

rol—Fieldbus

.for.use.in.indu

strial

.cont

rol

.system

.Int

ernational

.Elec

trotechnical

Commi

ssion,

.Gen

eva,

.Sw

itzerland,

.2007.

. 2.. Int

ernational

.Ele

ctrotechnical

.Com

mission,

.IEC.617

84-1.

.Ind

ustrial

.Com

munication

.Net

works—

Profiles—Part

. 1:. Fie

ldbus

. pro

files,

. Int

ernational

. Ele

ctrotechnical

. Com

mission,

. Gen

eva,

Swi

tzerland,

.200

. 3.. Int

ernational

.Elec

trotechnical

.Commi

ssion,

.IEC.61784-2..Ind

ustrial

.Comm

unication

.Netw

orks—

Proles—Part

. 2:. Addit

ional

. eldb

. pro

les

. for. rea

l-time

. netw

orks

. bas

. on.ISO/IEC. 8802-3,.

Int

ernational

.Ele

ctrotechnical

.Co

mmission,

.Gen

eva,

.Sw

itzerland,

.2007.

. 4.. Pro

bus

. Int

ernational,

. GSDML

Specication for Pronet IO,

. Versio

. 2.20,. Order. No.. 2.352,.

PRO

FIBUS

.Nu

tzerorganisation

.e.V

.Ka

rlsruhe,

.Ger

many,

.2008.

. 5.. Pro

bus

.Int

ernational,

.Pro

le Guidelines Part 1: Identication & Maintenance Functions,

.Versio

1.1.1,.Order.No

.3.502,.PR

OFIBUS

.Nu

tzerorganisation

.e.V

.Ka

rlsruhe,

.Ger

many,

.2005.

41-1

41.1 Introduction

LonWorks.or.local.operating.network.(LON).is.an.event-triggered.control.network.system.originally.

desig

ned

.by.Eche

lon

.Corp

oration

.in.1990

.It.consi

sts

.of.a.comm

unication

.proto

col

.call

.LonT

alk,

.a.

spec

ial

.cont

roller

.(the.Neur

.Chip

.tran

sceivers

.for.bus.acce

ss,

.and.a.set.of.deve

lopment

.and.mana

ge-

ment

.tool

.main.appl

ication

.of.LonW

orks

.is.buil

ding

.and.home.autom

ation,

.wher

.it.is.used.to.cont

rol

and.moni

tor,

.amon

.othe

rs,

.heat

ing,

.vent

ilating,

.and.air-

conditioning

.(HVA

C),

.ligh

ting,

.secu

rity,

.and.

elev

ators.

.But.also.othe

.appl

ication

.area

.exis

.such.as.indu

strial

.autom

ation,

.tran

sportation

.autom

tion,

.and.str

eet

.lig

hting.

.LonT

alk

.comm

unication

.prot

ocol,

.whic

.impl

ements

.the.OSI.refe

rence

.mode

.was.stan

dard-

ized

.as.ANSI

/EIA-709

.and.ANSI

/CEA-709

.in.1999

.Both.stan

dards

.also.incl

ude

.the.chan

nel

.spec

cations

.of.free

-topology

.twis

ted-pair,

.powe

.line.and.ber

-optics,

.whic

.are. used. for.LonW

orks

netw

orks.

. e.LonT

alk

.prot

ocol

.ANSI

/CEA-709

.was.revi

sed

.in.2002.[1].and.was.rele

ased

.as.Euro

pean

Stan

dard

.EN-1

4908

.[2].in.2005

. e.corr

esponding

.inte

rnational

.stan

dard

.ISO/

IEC-14908

.is.cur-

ently

.in.dra.stat

.[3].

uidelines

. for. the. impl

ementation

. of. the. appl

ications

. on. the. Neur

. Chip

. are. den

. by. the.

LonM

ark,

.a.glo

bal

.memb

ership

.org

anization

.tha

.pro

motes

.and.adv

ances

.the.Lon

Works

.pla

tform.

41.2 System Components

LonWorks.networks.normally.consist.of.network.nodes,.based.on.the.Neuron.Chip..In.the.rst.years,.

these.chip

.were.manu

factured

.by.Moto

rola

.[4].and.Tosh

iba

.[5]..Toda

y’s

.mode

.are.buil

.by.Cypre

.[6].

and.Eche

lon

.itse

lf.

.Eche

lon

.oer

.so-c

alled

.smar

.tran

sceivers,

.whic

.inte

grate

.a.Neur

.Chip.and.

atran

sceiver

.into.one.chi

.[7]

LonWorks

41.1. Introduction.....................................................................................41-1

41.2

. Syst

.Com

ponents........................................................................ 41-1

41.3

. LonT

alk

.Pro

tocol.............................................................................41-4

Physical.Layer. •. Link.Layer. •. Network.Layer. •. Transport.

andSession.Layer. •. Application.and.Presentation.Layer

41.4. e.Application.Layer.Programming.Model.............................. 41-7

41.5

. Func

tion

.Blo

ck-Based

.Desi

.and.Sys

tem

.Int

egration.............41-8

41.6

. Netw

ork

.Desi

.Too

ls................................................................... 41-11

41.7

. Autom

atic

.Desi

.App

roaches....................................................41-12

References................................................................................................... 41-13

Uwe Ryssel

Dresden University

of Tec

hnology

Henrik Dibowski

Dresden University

of Tec

hnology

Heinz Frank

Reinhold-Würth-University

Klaus Kabitzsch

Dresden University

of Tec

hnology

41-2 Industrial Communication Systems

As.shown.in.Figure.41.1,.the.Neuron.Chip.implements.a.three-processor.architecture.with.shared.

memory,.which.includes.the.rmware.ROM,.an.EEPROM.for.the.user.application.program,.and.RAM..

Each.of.the.three.processors.handles.a.certain.task:

.media access control.(MAC).processor.sends.and.receives.messages.to.and.from.the.communi-

cation

.medium.with.support.of.the.transceiver,.which.handles.the.line.coding.for.a.specic.medium..

Since.many.dierent.transceiver.types.exist,.a.wide.range.of.communication.media.can.be.used,.such.

as.twisted.pair,.power.line,.ber.optics,.and.radio.frequency.. e.network processor.handles.the.upper.

layers.of.the.LonTalk.protocol,.which.are.described.in.the.next.section..And.the.application processor.

runs.the.user.application.implementing.the.specic.task.of.the.node.

.communication.among.the.three.processors.is.realized.in.shared.RAM.by.communication.buf-

fers

.and.ags.. ere.are.input.and.output.buer.queues.storing.messages.to.be.forwarded.to.the.other.

processors..Special.ag.bytes.indicate.that.the.other.processor.should.do.a.certain.action,.such.as.creat-

ing,

.sending,.or.receiving.a.message.

Peripheral

.hardware,.such.as.sensors.and.actuators,.are.connected.to.a.set.of.I/O.pins,.which.can.be.

congured.in.a.range.of.single.bit.input.and.output.for.switches.or.LEDs.via.nibble.and.byte.input.and.

output.up.to.higher.I/O.protocols,.such.as.serial.and.parallel.interfaces,.I

C,.and.Magcard.

 ere

.are.also.alternatives.to.the.Neuron.Chip..For.example,.LOYTEC.oers.a.more.powerful.ARM7-

based

.embedded.controller.(LC3020).that.implements.the.LonTalk.protocol.according.to.CEA-709.as.

well..It.also.supports.LonWorks/IP.(standardized.as.CEA-852.[8]),.where.LonTalk.messages.are.tun-

neled

.over.LAN.or.Internet.in.IP.packets..Such.controllers.are.used.for.more.complex.tasks,.like.panels.

with.a.graphical.user.interface.or.IP.routers.

.identify.the.LonWorks.nodes.in.the.network,.each.Neuron.Chip.has.a.xed.48.bit.identier.called.

Neuron ID.assigned.by.the.manufacturer..A.LonWorks.node.can.actively.transmit.its.Neuron.ID.in.a.

service pin message,.when.a.special.service.pin.is.pressed.on.the.node.. is.simplies.the.network.inte-

gration,

.when.new.nodes.have.to.be.added.to.the.network,.because.it.is.not.required.to.enter.the.Neuron.

ID.manually.in.the.management.tool..Instead,.the.management.tool.simply.has.to.wait.for.the.service.

pin.message.

During

.conguration,.a.logical.address.is.assigned.to.each.node..It.consists.of.the.domain,.subnet,.

and.node ID.. e.domain.represents.a.whole.LonWorks.network,.which.is.identied.by.the.domain.ID.

with.up.to.6.bytes.length..Direct.message.passing.among.domains.is.not.possible,.but.it.can.be.done.via.

gateways.

MAC

processor

Control

Network

processor

Timer/

counter

Application I/O

Network

Com. Port

CP 0 ... 4

To transceiverTo application specic HWClockServiceReset

IO 0 ... 10

Appl.

processor

ROM

EEPROM

RAM

To external memory

Address bus (16 bit) Data bus (8 bit)

FIGURE 41.1 Structure.of.a.Neuron.Chip.

LonWorks 41-3

 e.physical.and.logical.view.of.a.LonWorks.network.example.is.shown.in.Figure.41.2.. e.network.

phy

sically

.con

sists

.of.sev

eral

.cha

nnels

.con

nected

.by.rou

ters

.and.rep

eaters.

.Log

ically,

.it.is.sep

arated

into.sub

nets.

.One.dom

ain

.can.con

sist

.of.up.to.255.sub

nets

.wit

.a.max

imum

.of.127.nod

.eac

.whi

res

ults

.in.a.max

imum

.of.32,

385

.nod

.per.dom

ain.

.Add

itionally,

.nod

.can.be.gro

uped.

.Per.dom

ain

.256.

gro

ups

.can.be.de

ned.

. e.exa

mple

.con

tains

.one.gro

up,

.whi

.spa

.thr

.nod

.in.di

erent

.sub

nets

and.ch

annels.

.men

tioned

.bef

ore,

.di

erent

.tra

nsceivers

.sup

port

.di

erent

.com

munication

.med

ia.

.A.com

mon

med

ium

.is.twi

sted

.pai

.wit

.a. dat

.rat

.of.78.kbp

.whe

.the.sign

.is.cod

.as.vol

tage

.di

erence

bet

ween

.the.two.con

ductors.

.A.com

patible

.var

iant

.of.twi

sted

.pai

.is.Lin

.Pow

er,

.whi

.als

.pro

vides

the.pow

.sup

ply

.(42

.V.DC).for.the.nod

.ove

.the.twi

sted

.pai

.med

ium.

.For.bac

kbones,

.twi

sted

.pai

can.als

.be.run.wit

.125

.kbp

.but.onl

.wit

.a.red

uced

.max

imum

.dis

tance

.of.130.m.amo

.the.nod

es.

.topo

logy

.of.twi

sted

.pai

.net

works

.doe

.not.hav

.to.be.a.str

ict

.lin

.or.sta

.Net

works

.can.als

be.bui

.as.fre

.topo

logy

.con

taining

.arb

itrary

.bra

nches

.and.loo

ps.

.How

ever,

.the.max

imum

.dis

tance

dec

reases

.whe

.usin

.fre

.topo

logy.

.So,.for.exa

mple,

.a.lin

.bus.wit

.sho

.bra

nches

.all

ows

.a.max

imum

dis

tance

.of.27

.m.am

ong

.th

.no

des,

.wh

ereas

.in.a.fr

.top

ology,

.it.is.li

mited

.to.50

.m.

her

.sup

ported

.med

.are.pow

.lin

.wit

.up.to.10.kbp

.be

.opti

.(1.

.Mbp

s),

.rad

.fre

quency

(up.to.19

.kbp

s),

.an

.th

.ab

ove-mentioned

.Lo

nWorks/IP

.(1

.Mbp

.wi

.cu

rrent

.IP.ro

uters).

.inc

rease

.the.max

imum

.dis

tance

.of.Lon

Works

.net

works,

.rep

eaters

.can.be.use

. ey.simp

.ref

resh

all.inc

oming

.sign

als

.and.sen

.the

.to.the.oth

.net

work

.seg

ment,

.whi

.has.to.be.the.sam

.med

ium

and.has.to.use.the.same.message.coding.

Since

.Lon

Talk

.imp

lements

.the.OSI.ref

erence

.mod

el,

.Lon

Works

.net

works

.can.be.con

nected

.at.hig

her

lay

ers,

.too..Bri

dges,

.wor

king

.on.the.dat

.lin

.lay

er,

.can.be.use

.to.con

nect

.net

works

.bas

.on.di

erent

med

.an

.co

ding.

. e

.al

.en

sure

.th

.on

.va

lid

.me

ssages

.ar

.fo

rwarded

.to.th

.ot

her

.sid

.com

mon

.tha

.pur

.Lon

Talk

.bri

dges

.are.rou

ters,

.whi

.wor

.on.the.net

work

.lay

er.

.Rou

ters

.hav

the.adv

antage

.tha

.the

.do.not.onl

.inc

rease

.the.ran

.of.the.sign

als

.or.con

nect

.di

erent

.med

ia,

.but.

the

.als

.sep

arate

.the.net

work

.tra

c

.of.di

erent

.sub

nets

.bec

ause

.rou

ters

.onl

.for

ward

.tho

.mes

sages,

who

.des

tination

.is.on.the.oth

.side.of.the.rou

ter.

. er

efore,

.rou

ting

.tab

les

.are.use

. ey.des

cribe

whi

.sub

nets

.or.gro

ups

.are.con

nected

.on.whi

.por

.of.the.rou

ter.

. er

.are.two.met

hods

.how.rou

ting

tab

les

.can.be.obt

ained:

.In.con

gured router

.mod

.the.tab

les

.hav

.to.be.de

ned

.by.the.sys

tem

.int

egrator

and.in.lea

rning router

.mod

.the.net

work

.tra

c

.is.use

.to.det

ermine

.whi

.sub

nets

.are.con

nected

.to.

whi

.po

rt.

.Lo

nWorks

.ro

uters

.ca

.al

.op

erate

.in.br

idge

.an

.re

peater

.mo

de.

Channel 1

Channel 2

Channel 3

Channel 4

Repeater

1/3

1/2

1/1

2/3

2/10 2/11

3/3

3/2

3/1

4/12

2/2

2/1

Router Router

Router

s/n ... Subnet/node address

Channel 5 (backbone)

Domain ID of all nodes: 0×53

Subnet 2

Subnet 4

Subnet 3

Group 1

Subnet 1

FIGURE 41.2 Physical.and.logical.segmentation.in.LonWorks.systems.

41-4 Industrial Communication Systems

41.3 Lontalk Protocol

 e.standardized.LonTalk.protocol.implements.all.seven.layers.of.the.OSI.reference.model..Especially,.

the.stan

dardization

.of.the.uppe

.appl

ication-oriented

.laye

.has.the.adva

ntage

.that.node

.from.die

rent

vend

ors

.are.comp

atible

.to.each.othe

.Figu

.41.3.oppo

ses

.the.laye

.of.the.OSI.refe

rence

.mode

.and.the.

LonT

alk

.lay

ers

.to.eac

.oth

er.

.die

rent

.laye

.are.pres

ented

.in.the.next.subs

ections,

.star

ting

.from.the.botto

.up..Deta

iled

info

rmation

.can.be.fou

.in.[10

41.3.1 Physical Layer

Since.LonWorks.supports.dierent.communication.media,.the.physical layer.is.not.xed.to.a.specic.line.cod-

ing

.meth

od.

.Inst

ead,

.each.medi

.can.use.its.own.meth

od.

.For.exam

ple,

.die

rential Manchester coding

.is.

used.for.twis

ted

.pair.line

.spre

ad spectrum modulation

.for.powe

.line

.and.freq

uency shi keying modulation

for.radi

.freq

uency

.comm

unication.

.A.spec

ial

.case.is.LonW

orks/IP,

.wher

.the.LonT

alk

.pack

.is.not.dire

ctly

modu

lated

.to.a.medi

um.

.Inst

ead,

.it.is.pack

.into.an.IP.pack

.and.tran

smitted

.over.LAN.or.the.Inte

rnet.

41.3.2 Link Layer

 e.next.layer.is.the.link layer.containing.the.MAC.sublayer.. is.sublayer.handles.the.medium.access,.

whic

.is.real

ized

.by.the.so-c

alled

.pred

ictive

.p-pe

rsistent

.carr

ier

.sens

.mult

iple

.acce

.(CSM

.meth

Layer 7

(Application layer)

Application and

presentation layer

Application interface,

network management

Session layer

Request/response service

Transport layer

(Un-)Acknowledged service

Authentication server

Transaction control sublayer

Packet order, duplicate detection

Network layer

Connectionless, topology, router

Link layer

Frame, coding, CRC

MAC sublayer

CSMA, collision avoidance,

collision detection, priorities

Physical layer

Media specific protocols

LonTalk protocolOSI model

Layer 6

(Presentation layer)

Layer 5

(Session layer)

Layer 4

(Transport layer)

Layer 3

(Network layer)

Layer 2

(Link layer)

Layer 1

(Physical layer)

FIGURE 41.3 e.OSI. reference. model. and.their. corresponding. LonTalk. layers..(From.Loy,. D..et. al.. (eds.),.

Open

Control Networks—LonWorks/EIA-709 Technology,

.Kluw

.Acad

emic

.Publ

ishers,

.Bost

on,

.MA,.p..76,.gure.

4-2,.200

.Wit

.kind.per

mission

.of.Spr

inger

.Sci

ence

.and.Bus

iness

.Med

ia.)