commiss decis technic specif interoper relat oper subsystem tran european high speed rail system refer articl council direct ec notifi document number text eea relev ec commiss european commun regard treati establish european commun regard council direct ec juli interoper tran european high speed rail network articl thereof accord articl direct ec tran european high speed rail system subdivid structur function subsystem subsystem annex ii direct accord articl direct subsystem cover technic specif interoper tsi accord articl direct draft tsi drawn joint repres bodi committe set pursuant articl direct ec appoint european associ railwai interoper aeif joint repres bodi accord articl direct aeif mandat draw draft tsi oper subsystem accord articl direct mandat establish accord procedur laid articl direct aeif drawn draft tsi introductori report cost benefit analysi provid articl direct draft tsi examin repres member state framework committe set direct light introductori report tsi subject decis impos specif technolog technic solut strictli interoper tran european high speed rail network tsi subject decis base expert knowledg time prepar draft develop technolog social requir make amend supplement tsi review updat procedur initi accord articl direct ec case tsi subject decis choic solut make appli definit transit interoper solut compat exist situat addit direct ec special implement provis specif case case provid articl direct member state allow appli technic specif member state ensur infrastructur regist roll stock regist publish updat year regist set main characterist nation infrastructur roll stock basic paramet concord characterist prescrib applic tsi end tsi subject decis precis inform regist applic tsi subject decis account specif criteria relat technic oper compat infrastructur roll stock servic network integr compat requir entail complex technic econom analysi case case basi analysi account interfac subsystem refer direct ec categori line roll stock refer direct technic oper environ exist network provis decis conform opinion committe set direct ec adopt decis articl tsi relat quot oper quot subsystem tran european high speed rail system refer articl direct ec adopt commiss tsi set annex decis tsi fulli applic infrastructur roll stock tran european high speed rail system defin annex direct ec take account condit set chapter attach tsi articl attach tsi enter forc month notif decis articl decis address member state brussel commiss loyola de palacio vice presid oj annex technic specif interoper relat oper subsystem introduct technic scope tsi concern quot oper quot subsystem subsystem list annex ii direct ec tsi part set tsi cover subsystem defin direct specif quot user quot quot environ quot subsystem ensur interoper tran european high speed rail system complianc essenti requir set tsi concern inform oper subsystem chapter geograph scope geograph scope tsi tran european high speed rail system annex direct ec refer made line tran european rail network decis ec european parliament council juli commun guidelin develop tran european transport network updat decis result revis provid articl decis content tsi accord articl annex direct ec tsi specifi essenti requir quot oper quot subsystem interfac chapter establish basic paramet annex ii direct meet essenti requir chapter establish condit compli achiev perform categori line chapter categori special built high speed line equip speed gener equal greater km categori ii special upgrad high speed line equip speed order km categori iii special upgrad high speed line special featur result topograph relief town plan constraint speed adapt case establish implement provis specif case chapter determin interoper constitu interfac cover european specif includ european standard need order achiev interoper tran european high speed rail system meet essenti requir chapter state case consider modul defin decis eec specif procedur order assess conform suitabl interoper constitu quot ec quot verif subsystem chapter subsystem definit scope applic oper subsystem tran european high speed rail system compris element implement function system scope railwai oper technic function element subsystem defin oper railwai system govern rule regul drawn infrastructur manag implement railwai undertak initi start oper railwai network requir qualifi staff appli procedur defin manner consist safeti system network main function relat oper safeti distinguish oper implement system train drive board staff ground base traffic manag organis handl design updat process procedur document function personnel involv identifi list document procedur publish regulatori document achiev interoper state document adapt address sole interoper take account human factor essenti depend effici applic procedur ideal solut standardis harmonis oper rule railwai relev rout difficult ideal achiev defeat quot safeti coher quot network imped safe run train rout contrari direct requir set essenti requir direct align network oper rule appli harmonis structur document driver instanc follow specif rule infrastructur manag rout safe effect convers procedur directli relat oper common system implement interoper network standardis qualif staff involv driver qualif contribut substanti maintain high level safeti organis uniform order achiev level safeti infrastructur network oper carri procedur member staff understand hesit whatsoev emerg situat make defin rule compli matter commun languag oper safeti requir consist check system verif feedback experi field scope applic defin rout train servic provid design set roll stock member staff aspect oper subsystem relat interoper tran european high speed rail system group head procedur document qualif personnel commun system monitor quot infrastructur manag quot mean bodi refer articl articl direct eec articl direct ec realloc task bodi infrastructur manag direct ec inform realloc mention network statement publish infrastructur manag accord direct ec essenti requir complianc essenti requir articl direct ec tran european high speed rail system subsystem interoper constitu meet essenti requir set gener term annex iii direct essenti requir aspect essenti requir cover safeti reliabl avail health environment protect technic compat direct ec essenti requir gener applic tran european high speed rail system specif subsystem constitu aspect relat specif oper subsystem case oper subsystem specif aspect addit consider annex iii direct safeti accord annex iii direct ec safeti relat essenti requir appli oper subsystem essenti requir quot design construct assembl mainten monitor safeti critic compon compon involv train movement guarante safeti level aim laid network includ specif degrad situat quot essenti requir relev oper subsystem essenti requir quot paramet involv wheel rail contact meet stabil requir need order guarante safe movement maximum authoris speed quot essenti requir relev oper subsystem essenti requir quot compon withstand normal except stress period servic safeti repercuss accident failur limit mean quot essenti requir relev oper subsystem essenti requir quot design fix instal roll stock choic materi aim limit gener propag effect fire smoke event fire quot essenti requir relev oper subsystem essenti requir quot devic intend handl user design impair safeti forese manner accord post instruct quot essenti requir relev oper subsystem safeti specif requir concern oper subsystem essenti requir quot align network oper rule qualif driver board staff ensur safe intern oper oper mainten interv train qualif mainten staff qualiti assur system set mainten centr oper concern ensur high level safeti quot part essenti requir align oper rule personnel qualif address subsect specif relat essenti human factor unic procedur appli ident situat directli link oper system subsect determin scope harmonis format document driver procedur subsect timet subsect develop quot procedur manual quot board staff subsect formalis harmonis descript line instal rout formalis process document inform driver advanc prepar updat process driver advis real time subsect formalis safeti messag methodolog specif languag type safeti relat voic commun section formalis process check system safeti standpoint section formalis process verif composit crew section formalis procedur follow run passeng overload section driver train crew qualif assur formalis harmonis organis set qualifi personnel standpoint procedur languag section formalis process rout learn mainten rout knowledg section definit programm special train specif qualif section concern train qualif mainten personnel requir applic personnel respons maintain roll stock address roll stock subsystem specif reliabl avail essenti requir quot monitor mainten fix movabl compon involv train movement organis carri quantifi manner maintain oper intend condit quot essenti requir relev oper subsystem essenti requir quot oper mainten period train qualif mainten staff qualiti assur system set oper concern mainten centr ensur high level system reliabl avail quot requir applic personnel respons maintain roll stock address roll stock subsystem specif health essenti requir quot materi virtu constitut health hazard access train railwai infrastructur quot essenti requir relev oper subsystem essenti requir quot materi select deploi restrict emiss harm danger fume gase event fire quot essenti requir relev oper subsystem environment protect essenti requir quot repercuss environ establish oper tran european high speed rail system assess account design stage system accord commun provis forc quot essenti requir relev oper subsystem essenti requir quot materi train infrastructur prevent emiss fume gase harm danger environ event fire quot essenti requir relev oper subsystem essenti requir quot roll stock energi suppli system design manufactur electromagnet compat instal equip public privat network interfer quot essenti requir relev oper subsystem technic compat essenti requir quot technic characterist infrastructur fix instal compat train tran european high speed rail system adher characterist prove difficult section network temporari solut ensur compat futur implement quot essenti requir relev oper subsystem essenti requir quot align oper rule network qualif driver board staff manag charg traffic ensur oper effici tran european high speed rail system quot essenti requir assur unic procedur appli ident situat directli link oper system subsect formalis safeti messag methodolog specif languag type safeti relat voic commun section provis assist driver event incid section inform traffic manag oper statu roll stock section formalis procedur scenario event major system degrad incid section formalis system complianc point view qualiti oper section verif conform verif conform subsystem constitu essenti requir made accord requir laid direct ec characteris oper subsystem tran european high speed rail system direct ec appli oper subsystem part integr system coher verifi basic paramet interfac perform purpos ensur interoper system complianc essenti requir basic paramet applic specif interoper element characteris oper subsystem shown paramet oper subsystem quot basic paramet quot list annex ii direct ec relev oper subsystem paramet relev subsystem oper subsystem meet perform line categori tran european high speed rail system relev line special construct high speed line special upgrad high speed line special upgrad high speed special featur case oper subsystem paramet met oper interoper high speed train specif relev high speed absenc definit train safeti critic element procedur oper system procedur ident situat link directli oper system intend interoper european network uniqu ertm etc compli european specif establish document driver document procedur procedur driver includ document comput medium call driver rule book driver rule book state requir rout work roll stock rout situat normal oper degrad oper driver meet driver rule book draft standardis outlin format organis servic person safeti signal command control run condit roll stock onboard system run drive train anomali incid accid appendix driver rule book manual commun procedur appendix driver rule book book form quot livret formulair quot driver rule book written languag state interoper network chosen railwai undertak liaison infrastructur manag network servic oper messag form quot formulair quot remain languag infrastructur manag subsect driver rule book written railwai undertak includ inform suppli infrastructur manag process prepar updat driver rule book includ step infrastructur manag im send railwai undertak delimit regul im languag railwai undertak draw initi updat document im languag infrastructur manag scrutinis part document prepar railwai undertak relev im infrastructur manag grant authoris element document concern im languag chosen railwai undertak infrastructur manag document translat compet acknowledg bodi chosen infrastructur manag railwai undertak railwai undertak provid certif complianc translat certif includ section messag form point request railwai undertak infrastructur manag particip translat process descript line linesid equip line work basic element item oper roll stock concern design rout set document comput medium call quot rout book quot rout book includ inform gener oper characterist type signal run regim doubl track work type power suppli type ground train radio equip indic rise fall gradient gradient valu precis delimit area steep gradient detail line diagram name station line kei locat locat permiss speed limit track roll stock concern name organis respons traffic manag identif radio channel schemat descript track layout format rout book prepar manner infrastructur work train individu railwai undertak rout book written languag member state interoper network chosen railwai undertak rout book written railwai undertak inform suppli infrastructur manag process prepar updat rout book defin railwai undertak infrastructur manag valid element document respons languag compet modifi element element modifi perman temporarili advis railwai undertak infrastructur manag group railwai undertak dedic document comput medium format infrastructur work train individu railwai undertak process document comput medium prepar defin railwai undertak valid infrastructur manag element respons languag compet inform driver real time procedur advis driver real time modif safeti arrang rout defin infrastructur manag concern process uniqu ertm etc roll stock inform run roll stock normal degrad situat driver compil document comput medium call quot driver roll stock book quot driver roll stock book prepar railwai undertak timet inform normal run train singl document comput medium call quot timet sheet quot quot fich train quot driver includ item stop point time point arriv departur pass time point timet sheet prepar railwai undertak concern compil time inform suppli infrastructur manag concern process prepar formalis railwai undertak valid infrastructur manag concern element document respons languag compet document board staff procedur board staff group document comput medium call quot board crew rule book quot board crew rule book prepar railwai undertak includ inform suppli infrastructur manag infrastructur manag request part relev document drawn updat accord process driver rule book subsect item roll stock board staff normal degrad situat collect document comput medium call quot board staff roll stock book quot board staff roll stock book written railwai undertak qualif driver train staff railwai undertak safeti relat duti basic qualif procedur languag driver train staff safeti duti railwai undertak appli qualif process consist phase element personnel select evalu personnel experi profession physic qualiti evalu compet foreign languag vocat field aptitud learn initi vocat train train requir specif train programm resourc qualif instructor initi certif draw requir certif programm licens certifi deliveri certif qualif mainten qualif level monitor personnel career monitor scheme health monitor scheme mainten qualif level refresh train principl assess train principl train implement principl train evalu mainten qualif level mainten continu certif principl continu certif formalis continu certif procedur qualif process defin take account rule appli concern infrastructur document describ detail process concern infrastructur manag rout knowledg railwai undertak defin process knowledg rout servic oper acquir maintain base rule laid infrastructur manag special qualif case includ regist infrastructur tunnel equip railwai undertak draw special train mainten knowledg programm train staff involv safeti procedur base rule set infrastructur manag concern safeti relat commun personnel natur format messag safeti relat commun methodolog principl appli railwai undertak infrastructur manag natur format messag commun methodolog defin annex present tsi oper item prepar facilit applic principl defin document driver traffic manag staff driver annex driver rule book annex manual commun procedur annex book form quot livret formulair quot languag ground train languag infrastructur concern decid infrastructur manag level knowledg safeti purpos drive function driver abil send understand messag annex present tsi content messag laid infrastructur manag train accompani function board staff abil send inform describ train oper statu staff concern measur deal situat involv passeng content messag laid infrastructur manag languag board staff board staff driver languag territori interoper network chosen railwai undertak languag board staff passeng situat relat passeng safeti health languag train staff passeng territori interoper network chosen railwai undertak agreement infrastructur manag infrastructur manag set rule specif case run long tunnel compli regul individu member state aid driver event incid major roll stock malfunct railwai undertak time train run expert contact directli driver real time event incid major malfunct roll stock investig inquiri accid incid railwai undertak agreement infrastructur manag person contact infrastructur manag agreement railwai undertak prescrib time scale investig inquiri accid incid commenc conserv extract read requir safeti relat event record railwai undertak establish agreement infrastructur manag procedur order action undertaken inform infrastructur manag train oper statu procedur defin infrastructur manag railwai undertak anomali affect roll stock repercuss train run prior departur en rout report organis respons traffic manag scenario procedur deal major incid scenario procedur infrastructur manag coordin railwai undertak incid accid rescu peopl roll stock failur evacu passeng rescu fail stock infrastructur failur drive condit rout train railwai undertak infrastructur manag account scenario procedur rule book personnel train specif order infrastructur manag pre establish measur rule regul depend natur incid tailwai undertak suppli request list specif malfunct roll stock substanti traffic implic run condit test train fail train condit run train roll stock test movement recov fail stock defin railwai undertak scrutinis endors infrastructur manag concern monitor system safeti point view check complianc specif complianc interoper specif check audit infrastructur manag carri minimum yearli audit network cover implement specif railwai undertak effect monitor system set railwai undertak inform railwai undertak find audit carri network railwai undertak make audit year interoper high speed servic concern commun find audit infrastructur manag concern feedback experi infrastructur manag set process feedback field inform oper perform interoper high speed system advis railwai undertak concern incid accid occur territori commun railwai undertak staff concern analys conclus investig inquiri railwai undertak set process feedback field inform oper perform interoper high speed system period need inform infrastructur manag result feedback area correct action expect monitor qualiti oper event significantli disrupt oper analys jointli railwai undertak infrastructur manag concern recur event analys jointli railwai undertak infrastructur manag concern year process defin railwai undertak agreement infrastructur manag board servic crew minimum number person board qualif accord train staf rule infrastructur work procedur drawn railwai undertak agreement infrastructur manag defin check made train depart number passeng board train railwai undertak high speed roll stock run nomin speed substanti passeng overload measur ensur overload situat occur except case situat occur railwai undertak advis infrastructur manag condit movement made case includ regist infrastructur tunnel infrastructur manag provid evacu scenario passeng walk train infrastructur manag railwai undertak fix maximum number passeng allow train case mention reason baggag permit aisl doorwai interfac oper subsystem perform interoper constitu mean articl direct ec interoper constitu quot elementari compon group compon subassembl complet assembl equip incorpor intend incorpor subsystem interoper tran european high speed rail system depend directli indirectli quot interoper constitu cover relev provis direct ec interoper constitu address specif set perform requir assess conform fit made rule interfac interoper constitu design descript characterist reli except oper subsystem interoper constitu assess conform fit interoper constitu oper tsi interoper constitu oper subsystem assess procedur modul applic conform assess paramet question involv verifi point paramet rout work roll stock prior entri servic characterist defin document procedur process special provis oper implement control defin element qualiti monitor system type modul appli conform assess prior start servic design paramet concern infrastructur manag type modul design paramet concern railwai undertak type modul conjunct addit provis quot notifi bodi chosen railwai undertak conduct verif characterist design paramet element concern prior start servic quot modul refer ae point oper paramet element relat qualiti monitor system type modul conjunct provis quot notifi bodi notifi institut chosen infrastructur manag railwai compani year assess element paramet relat qualiti monitor system process applic qualiti monitor system identifi sq tabl concern railwai undertak infrastructur manag choic notifi bodi made procedur laid member state concern notifi bodi essenti skill agreement author appoint member state concern issu safeti certif quot modul refer de point applic modul tabl list paramet assess element verifi paramet identifi qualiti monitor system element assess mark sq tsi refer paramet modul tabl basi appli modul gt tabl gt sq element qualiti monitor system verifi oper arrang implement modul modul produc infrastructur manag element paramet concern draw oper document interoper system question document roll stock rout work document paramet document process procedur special provis list european specif appli archiv materi keep inspect nation author period year verifi paramet design element paramet list characterist defin tsi compli draw declar conform includ list paramet element verifi previou tabl indic complianc declar archiv oper document modul ae produc railwai undertak element concern draw oper document interoper system question document roll stock rout work document paramet document word process procedur special provis list european specif appli archiv materi keep inspect nation author period year select notifi bodi request verif paramet design paramet element list characterist defin tsi compli rout work notifi bodi verifi paramet design paramet element list characterist defin tsi compli notifi produc request verif result obtain produc draw declar conform includ list paramet element verifi tabl indic conform declar archiv oper document modul de produc railwai undertak infrastructur manag part concern draw oper document interoper system question document roll stock rout work document organis respons power relat qualiti monitor system document paramet relat oper qualiti monitor system process result audit element feedback element qualiti monitor system archiv materi keep inspect nation author period year select notifi bodi notifi institut year request conduct assess element paramet relat qualiti monitor system applic qualiti monitor process identifi sq tabl concern notifi bodi notifi institut conduct assess monitor process concern produc railwai undertak infrastructur manag draw report indic produc implement process plan produc control process result assess relat report produc request report produc railwai undertak infrastructur manag part concern establish complianc declar indic result assess relat report declar oper document implement oper tsi oper train servic relev part tran european high speed rail system conform oper tsi upgrad interoper infrastructur put servic accord articl direct ec cross border servic put servic case exist infrastructur refer point present tsi step step case infrastructur exist train run subject direct ec oper rule result applic tsi adapt local situat view preserv compat exist rail system current safeti level except mention infrastructur regist annex safeti relat commun personnel involv subsystem natur structur messag commun methodolog introduct purpos document set rule safeti relat ground mobil mobil ground commun applic inform transmit exchang safeti critic situat interoper network defin natur structur safeti relat messag defin methodolog voic transmiss messag appendix serv basi enabl infrastructur manag draw messag book form formulair element address railwai undertak time delimit rule regul made infrastructur manag railwai undertak draw document oper book form livret formulair instruct personnel respons traffic manag appendix driver rule book quot manual commun procedur quot natur structur safeti relat messag natur safeti relat messag defin formal manner infrastructur manag type top prioriti emerg messag procedur messag addit messag inform messag variabl content rule transmiss messag section quot commun methodolog quot top prioriti emerg messag top prioriti emerg safeti messag intend give urgent oper instruct avoid risk misunderstand messag repeat classifi main messag addit top prioriti emerg messag defin infrastructur manag top prioriti emerg messag procedur messag subsect essenti top prioriti emerg messag appendix quot manual commun procedur quot rule book driver document instruct personnel respons traffic manag messag ground driver stop train gt pic file quot en tif quot gt inform locat area messag addit messag quickli complement reason locat emerg train identif gt pic file quot en tif quot gt stop train gt pic file quot en tif quot gt radio silenc gt pic file quot en tif quot gt messag issu driver cut traction power suppli gt pic file quot en tif quot gt messag quickli complement reason locat emerg train identif gt pic file quot en tif quot gt procedur messag natur messag procedur messag send oper instruct situat repres driver rule book compris text messag situat number identifi messag messag requir recipi report back text report messag predetermin word prescrib infrastructur manag languag present form pre print paper form procedur form procedur form formalis medium procedur messag purpos provid common work document real time ground staff respons traffic manag driver enabl traceabl commun form identifi uniqu code word number relat procedur drawn infrastructur manag languag book form livret formulair set form collect book book form paper form book form intend driver group form infrastructur manag rout travel book form constitut appendix driver rule book book form intend personnel respons traffic manag allow put practic procedur territori book form part part compris item remind utilis book form index ground origin procedur form index driver origin procedur form list situat cross referenc procedur form glossari give situat procedur form appli code spell messag phonet alphabet part procedur form model form includ book form page divid railwai undertak includ explanatori text relev form situat cover driver book form addit messag addit messag inform messag driver inform personnel charg traffic manag personnel charg traffic manag advis driver predict situat relat train run technic condit train infrastructur addit messag identifi infrastructur manag includ appendix quot manual commun procedur quot driver rule book document instruct personnel charg traffic manag inform messag variabl content messag situat driver advis personnel charg traffic manag ground circumst rare natur predetermin messag provid make easier describ situat construct inform messag messag model glossari railwai terminolog descript diagram roll stock emploi descript statement infrastructur equip track traction suppli drawn model structur messag gt pic file quot en tif quot gt messag request instruct element messag provid languag chosen railwai undertak concern infrastructur manag glossari railwai terminolog glossari railwai terminolog produc railwai undertak network travers suppli term regular languag chosen railwai undertak infrastructur manag infrastructur work compos part list term subject matter list term alphabet order descript diagram roll stock descript diagram roll stock prepar railwai undertak list name compon subject commun infrastructur manag concern provid common name standard term languag chosen railwai undertak infrastructur manag infrastructur work descript statement characterist infrastructur equip track traction suppli descript statement characterist infrastructur equip track traction suppli rout work drawn railwai undertak show name compon subject commun infrastructur manag concern provid common name standard term languag chosen railwai undertak infrastructur manag infrastructur work commun methodolog element rule methodolog glossari term procedur speech transmiss procedur term transfer opportun speak opposit parti messag receiv procedur receiv direct messag term confirm messag receiv receiv term messag repeat event poor recept misunderstand speak slowli recept messag read back term ascertain read back messag match messag correct error commun break procedur messag end break temporari break connect term parti wait wait break temporari connect broken term parti commun broken resum call messag cancel procedur term cancel procedur underwai cancel procedur messag subsequ resum procedur repeat start rule appli event error misunderstand permit correct error commun rule appli error error transmiss transmiss error discov sender sender request cancel send procedur messag error prepar form error send initi messag error read back sender discov error whilst messag read back sender send procedur messag error send initi messag misunderstand parti misunderstand messag parti repeat messag text speak slowli word number time distanc speed date spell code aid understand express messag situat term pronounc slowli correctli spell word figur misunderstood spell rule appli spell word letter group intern phonet alphabet alpha bravo charli delta echo foxtrot golf hotel india juliet kilo lima mike novemb oscar papa quebec romeo sierra tango uniform victor whiski rai yanke zulu exampl point point alpha bravo signal number kx signal kilo rai railwai undertak add indic pronunci deem express number number spoken digit digit train train decim express word point point express time time local time plain languag hour ten fifti time spell digit digit hour express distanc speed distanc express kilometr speed kilometr hour mile unit infrastructur concern express date date express usual manner decemb commun structur voic transmiss safeti relat messag principl compris phase identif request instruct transmiss messag termin transmiss phase cut back omit top prioriti safeti messag rule identif request instruct enabl parti identifi defin oper situat transmit procedur instruct rule appli identif commun top prioriti safeti messag begin identif messag interrupt transmiss messag purpos parti personnel respons traffic manag train number signal driver signal train number nb identif addit inform messag give person respons traffic manag detail situat determin precis procedur driver subsequ requir follow request instruct applic procedur preced request instruct term request instruct prepar procedur rule messag transmiss procedur top prioriti safeti messag due urgent imper natur messag receiv run omit identif part repeat inform procedur messag order reliabl send standstil procedur messag contain book form livret formulair rule messag send form complet prior transmit messag full text messag singl transmiss messag receiv receiv messag fill form book form base inform sender read back predetermin railwai messag book form requir read back read back includ messag shown grei field form report back section addit complementari inform acknowledg correct read back read back messag acknowledg conform conform sender messag correct error resend initi messag acknowledg messag receiv acknowledg posit neg receiv neg speak slowli traceabl verif uniqu identif authoris number accompani messag initi ground messag concern action driver requir specif authoris pass signal danger authoris number case proceed caution messag number report back messag compris request quot report back quot quot report quot addit messag addit messag preced identif procedur short precis limit inform commun appli read back acknowledg correct read back request instruct request inform inform messag variabl content predetermin inform messag variabl content preced identif procedur prepar send read back acknowledg correct read back