交叉25码(itf)编码方式

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1、INTERLEAVED2OF5SYMBOLOGY(ITF)INTERLEAVED2OF5BACKGROUNDINFORMATIONInterleaved2of5isahigher-densitynumericsymbologybasedupontheStandard2of5symbology.Itisusedprimarilyinthedistributionandwarehouseindustry.Interleaved2of5encodesanyevennumberofnumericcharactersinthewidths(eithernarroworwid

2、e)ofthebarsandspacesofthebarcode.UnlikeStandard2of5,whichonlyencodesinformationinthewidthofthebars,Interleaved2of5encodesdatainthewidthofboththebarsandspaces.ThisallowsInterleaved2of5toachieveasomewhathigherdensity.Thesymbologyiscalled"interleaved"becausethefirstnumericdataisencodedin

3、thefirst5barswhilethesecondnumericdataisencodedinthefirst5spacesthatseparatethefirst5bars.Thusthefirst5barsandspacesactuallyencodetwocharacters.Thisisalsowhythebarcodecanonlyencodeanevennumberofdataelements.AtypicalInterleaved2of5barcodeis:Notethattheabovebarcodeisphysicallysmallertha

4、nitsequivalentrepresentationusingStandard2of5.NOTE:Interleaved2of5isessentiallyidenticaltoStandard2of5exceptforthefactthatInterleaved2of5encodesinformationinboththebarsandspaceswhileStandard2of5onlyencodesinformationinthebars.However,theencodingschemeisthesameforbothintermsoftheiruseo

5、fwideandnarrowelementsforeachelement.COMPUTINGTHECHECKSUMDIGITInterleaved2of5issimilartoStandard2of5inthesensethatitmayincludeanoptionalmodulo10checkdigit.PleaseseethesectionconcerningComputingtheChecksumdigitintheStandard2of5page.TheprocessforcalculatingthecheckdigitisthesameinInterl

6、eaved2of5asitisinStandard2of5.And,likeStandard2of5,thechecksumdigitisoptional.NOTE:InthecaseofInterleaved2of5,thetotallengthofthevaluetobeencodedmustbeeven.Ifyouaregoingtocomputeandappendachecksumvalue,theactualdataitselfmustbeoddinlengthsuchthatwhentheadditionalchecksumvalueisappende

7、d,thetotallengthwillbeeven.ENCODINGTHESYMBOLInthefollowingtext,wewilldiscusstheencodingofthebarcodebyconsideringthatthenumber"1"representsa"dark"or"bar"sectionofthebarcodewhereasa"0"representsa"light"or"space"sectionofthebarcode.Thusthenumbers1101representsadouble-widebar(11),followed

8、byasi