BarCodeTechnologyanditsapplication條碼碼制的選擇BarCodeSystemSelectionBarCodeSystemSelection用戶在設計自己的條碼應用系統(tǒng)時，碼制的選擇是一項十分重要的內(nèi)容。選擇合適的碼制會使條碼應用系統(tǒng)充分發(fā)揮其快速、準確、成本低等優(yōu)勢，達到事半功倍的目的。Whenusersdesigntheirownbarcodeapplicationsystem,thechoiceofbarcodesystemsisveryimportant.Therightcodesystemwillmakethebarcodeapplicationsystemgivefullplaytoitsadvantagesofspeed,accuracyandlowcost,andachievethegoalofgettingtwicetheresultwithhalftheeffort.影響碼制選擇的因素很多，如識讀設備的精度、識讀范圍、印刷條件及條碼字集中包含字符的個數(shù)等。Therearemanyfactorsaffectingthechoiceofacodesystem,suchastheaccuracyofreadingequipment,readingrange,printingconditionsandthenumberofcharactersinthebarcodecharacterset.BarCodeSystemSelection必須優(yōu)先從國家（或國際）標準中選擇碼制，例如通用商品條碼（EAN條碼）。它是一種在全球范圍完全通用的條碼，所以我們在自己的商品上印制條碼時，不得選用EAN/UPC碼制以外的條碼，否則無法在流通中通用。為了實現(xiàn)信息交換與資源共享，對于已制定為強制性國家標準的條碼，必須嚴格執(zhí)行。Acodesystemmustbeselectedfromanational(orinternational)standard,suchasEANbarcode.Itisacompletelyuniversalbarcodeintheglobalscope,sowhenweprintbarcodesonourgoods,weshallnotchoosebarcodesotherthanEAN/UPCcodesystem,otherwiseitcannotbeusedincirculation.Inordertorealizeinformationexchangeandresourcesharing,barcodesthathavebeensetasmandatorynationalstandardsmustbestrictlyimplemented.1．使用國家標準的碼制1.UsenationalstandardcodesystemsBarCodeSystemSelection在沒有合適的國家標準供選擇時，需參考一些國外的應用經(jīng)驗。有些碼制是為滿足特定場合實際需要而設計的，像庫德巴條碼，它起源于圖書館行業(yè)，發(fā)展于醫(yī)療衛(wèi)生系統(tǒng)。國外的圖書情報、醫(yī)療衛(wèi)生領域大都采用庫德巴條碼，并形成一套行業(yè)規(guī)范。所以在圖書情報和醫(yī)療衛(wèi)生系統(tǒng)最好選用庫德巴條碼。貿(mào)易項目的標識、物流單元的標識、資產(chǎn)的標識、位置的標識、服務關系的標識和特殊應用等六大應用領域大都采用GS1-128碼。Whenthereisnosuitablenationalstandardforchoice,someforeignapplicationexperienceshouldbereferredto.Somecodesaredesignedtomeettheactualneedsofspecificoccasions,suchastheCodabarcode,whichoriginatedinthelibraryindustryandisdevelopedinthehealthcaresystem.Mostforeignlibraryandinformation,medicalandhealthfieldsusetheCodabarcode,andformasetofindustrystandards.SointhelibraryinformationandhealthcaresystemsCodabarcodeisthebestchoice.GS1-128codeismostlyusedinsixapplicationfields:tradeprojectidentification,logisticsunitidentification,assetidentification,locationidentification,servicerelationshipidentificationandspecialapplications.BarCodeSystemSelection條碼字符集的大小是衡量一種碼制優(yōu)劣的重要標志。碼制設計者在設計碼制時往往希望自己的碼制具有盡可能大的字符集及盡可能少的替代錯誤，但這兩點是很難同時滿足的。因為在選擇每種碼制的條碼字符構成形式時需要考慮自檢驗等因素。每一種碼制都有特定的條碼字符集，所以用戶自己系統(tǒng)中所需代碼字符必須包含在要選擇的字符集中。Thesizeofthebarcodecharactersetisanimportantindicatortomeasuretheprosandconsofacodesystem.Whendesigningacodesystem,designersoftenwanttheircodesystemtohaveaslargeacharactersetaspossibleandasfewsubstitutionerrorsaspossible,butitisdifficulttosatisfythesetwopointsatthesametime.Thereasonisthatself-checkingandotherfactorsshouldbeconsideredwhenselectingthecharactercompositionformofeachcodesystem.Eachcodesystemhasaspecificbarcodecharacterset,sotherequiredcodecharactersintheuser'sownsystemmustbeincludedinthecharactersettobeselected.2．條碼字符集2.BarcodecharactersetBarCodeSystemSelection當印刷面積較大時，可選擇密度低、易實現(xiàn)印刷精確的碼制，如25條碼、39條碼。反之若印刷條件允許，可選擇密度較高的條碼如庫德巴條碼。當印刷條件較好時，可選擇高密度條碼，反之則選擇低密度條碼。Whentheprintingareaislarge,thecodesystemwithlowdensityandeasytorealizeprintingaccuracycanbeselected,suchascode25andcode39.Onthecontrary,ifprintingconditionspermit,youcanchooseahighdensitybarcodesuchasCodabarcode.Whentheprintingconditionsaregood,choosehighdensitybarcode,otherwisechooselowdensitybarcode.3．印刷面積與印刷條件3.PrintingareaandprintingconditionsBarCodeSystemSelection每一種識讀設備都有自己的識讀范圍，有的可同時識讀多種碼制，有的只能識讀一種或幾種。所以當用戶在現(xiàn)有識讀設備的前提下選擇碼制時也應加以考慮，以便與自己的現(xiàn)有設備相匹配。Eachkindofreadingdevicehasitsownrangeofreading.Somecanreadmultiplecodesatthesametime;somecanonlyreadoneorseveralcodes.Therefore,whenuserschoosethecodesystemonthepremiseofexistingreadingequipment,theyshouldchoosetherightsystemtomatchwiththeirexistingequipment.4．識讀設備4.ReadingequipmentBarCodeSystemSelection即使用戶所涉及的條碼應用系統(tǒng)是封閉系統(tǒng)，考慮到設備的兼容性和將來系統(tǒng)的延拓，最好還是選擇常用碼制。當然對于一些保密系統(tǒng)，用戶可選擇自己設計的碼制。Evenifthebarcodeapplicationsystemisaclosedsystem,itisbesttochooseacommoncodesystemforthecompatibilityoftheequipmentandtheextensionofthefuturesystem.Ofcourse,forsomesecuritysystems,userscanchooseacodesystemdesignedbythemselves.5.盡量選擇常用碼制5.Trytousecommoncodes微課作業(yè)MicroClassAssignments條碼應用系