s7-200 编程实例_原创精品文档.pdfVIP

s7-200编程实例

EnglishAnswer:

S7-200ProgrammingExample.

Inthisprogrammingexample,wewilldiscusshowto

programtheS7-200PLC(ProgrammableLogicController).The

S7-200PLCisapopularchoiceforsmalltomedium-sized

automationprojectsduetoitscompactsizeandeaseofuse.

TobeginprogrammingtheS7-200PLC,weneedtousea

programmingsoftwarecalledSTEP7-Micro/WIN.Thissoftware

allowsustocreateandedittheladderlogicprogramthat

willcontrolthePLC.

OncewehaveinstalledtheSTEP7-Micro/WINsoftware,

wecanconnectourPCtotheS7-200PLCusingaprogramming

cable.ThiscableisusuallyprovidedwiththePLCorcan

bepurchasedseparately.Thecableconnectstothe

programmingportonthePLCandtheserialorUSBporton

thePC.

Oncetheconnectionisestablished,wecanopenthe

STEP7-Micro/WINsoftwareandcreateanewproject.Inthe

project,wecandefinethehardwareconfigurationofthe

PLC,suchasthenumberandtypeofinputandoutput

modules.

Next,wecanstartprogrammingthePLCbycreating

ladderlogicdiagrams.Ladderlogicisagraphical

programminglanguagethatrepresentsthecontrollogicina

relayladderdiagramformat.

Forexample,letssaywewanttoprogramtheS7-200

PLCtocontrolamotor.Wecancreatealadderlogic

diagramthatincludesaninputcontacttomonitorastart

button,acoiltocontrolthemotor,andatimertocontrol

themotorsrunningtime.

Inladderlogic,wecanusevariousinstructionssuch

ascontacts,coils,timers,counters,andarithmetic

operationstocreatethedesiredcontrollogic.These

instructionscanbeeasilydraggedanddroppedfromthe

softwaresinstructionlibrary.

Oncetheladderlogicprogramiscreated,wecan

downloadittotheS7-200PLCusingtheprogrammingcable.

TheprogramisstoredinthePLCsmemoryandwillbe

executedinreal-timetocontroltheconnected