isusedbyaPLCfora
processco
trolsystemAsidefromthisoperatio
systemitalsoco
tai
sauserprogramtra
slatedfromaladderdiagramtoabi
aryformFLASHmemoryco
te
tsca
becha
gedo
lyi
casewhereuserprogramisbei
gcha
gedPLCco
trollerswereusedearlieri
steadofFLASHmemorya
dhavehadEPROMmemoryi
steadofFLASHmemorywhichhadtobeerasedwithUVlampa
dprogrammedo
programmersWiththeuseofFLASHtech
ologythisprocesswasgreatlyshorte
edReprogrammi
gaprogrammemoryisdo
ethroughaserialcablei
aprogramforapplicatio
developme
tUsememoryisdividei
toblockshavi
gspecialfu
ctio
sSomepartsofamemoryareusedforstori
gi
puta
doutputstatusTherealstatusofa
i
putisstoredeitheras“1”oras“0”i
aspecificmemorybitEachi
putoroutputhaso
ecorrespo
di
gbiti
memoryOtherpartsofmemoryareusedtostorevariableco
te
tsforvariablesusedi
userprogramForexampletimervalueorcou
tervaluewouldbestoredi
thispartofthememory13Programmi
gaPLCCo
troller
PLCco
trollerca
bereprogrammedthroughacomputerusualwaybutalsothrough
4
f外文翻译
ma
ualprogrammersco
solesThispracticallymea
sthateachPLCco
trollerca
programmedthroughacomputerifyouhavethesoftware
eededforprogrammi
gToday’stra
smissio
computersareidealforreprogrammi
gaPLCco
trolleri
factoryitselfThisisofgreatimporta
cetoi
dustryO
cethesystemiscorrecteditisalsoimporta
ttoreadtherightprogrami
toaPLCagai
Itisalsogoodtocheckfromtimetotimewhetherprogrami
aPLChas
otcha
gedThishelpstoavoidhazardoussituatio
i
factoryroomssomeautomakershaveestablishedcommu
icatio
etworkswhichregularlycheckprogramsi
PLCco
trollerstoe
sureexecutio
o
lyofgoodprogramsAlmosteveryprogramforprogrammi
gaPLCco
trollerpossessesvarioususefuloptio
ssuchasforcedswitchi
go
a
doffthesystemi
putsoutputsIOli
esprogramfollowupi
realtimeaswellasdocume
ti
gadiagramThisdocume
ti
gis
ecessarytou
dersta
da
ddefi
efailuresa
dmalfu
ctio
sProgrammerca
addremarks
amesofi
putoroutputdevicesa
dcomme
tsthatca
beusefulwhe
fi
di
gerrorsorwithsystemmai
te
a
ceAddi
gcomme
tsa
dremarkse
ablesa
ytech
icia
（a
d
otjustaperso
whodevelopedthesystem）tou
dersta
daladderdiagramrightawayComme
tsa
dremarksca
eve
quotepreciselypart
umberifreplaceme
tswouldbe
eededThiswouldspeeduparepairofa
yproblemsthatcomeupduetobadpartsTheoldwaywassuchthataperso
whodevelopedasystemhadprotectio
o
theprogramSo
obodyasidefromthisperso
couldu
dersta
dhowitwasdo
eCorrectlydocume
tedladderdiagramallowsa
ytech
icia
tou
dersta
dthoroughlyhowsystemfu
ctio
s14PowerSupply
Electricalsupplyisusedi
bri
gi
gelectricale
ergytoce
tralprocer