淺談兩種儀器功能在計算機上的軟、硬件實現
多道幅度分析器和單道定標計數器是從事核科學實驗常用的實驗儀器,本文描述了這兩種儀器功能在計算機上的軟、硬件實現,並對該虛擬儀器在基於C/S和B/S兩種網絡模式上的構建進行了探討。多道幅度分析器的功能分析和軟、硬件實現多道幅度分析器是對探測到的核脈衝按不同的幅度進行計數,每個幅度值對應一道,最終繪製出道數―計(ji)數(shu)圖(tu),找(zhao)到(dao)計(ji)數(shu)峰(feng)值(zhi)對(dui)應(ying)的(de)幅(fu)度(du)值(zhi),從(cong)而(er)對(dui)核(he)脈(mai)衝(chong)進(jin)行(xing)準(zhun)確(que)的(de)能(neng)譜(pu)分(fen)析(xi)。要(yao)實(shi)現(xian)該(gai)功(gong)能(neng),必(bi)須(xu)要(yao)有(you)速(su)度(du)足(zu)夠(gou)快(kuai)的(de)數(shu)據(ju)采(cai)集(ji)卡(ka),因(yin)為(wei)核(he)脈(mai)衝(chong)上(shang)升(sheng)沿(yan)非(fei)常(chang)快(kuai),脈(mai)峰(feng)很(hen)尖(jian),另(ling)外(wai)數(shu)據(ju)采(cai)集(ji)卡(ka)還(hai)應(ying)該(gai)具(ju)有(you)閾(yu)值(zhi)觸(chu)發(fa)功(gong)能(neng),由(you)於(yu)核(he)脈(mai)衝(chong)的(de)產(chan)生(sheng)具(ju)有(you)隨(sui)機(ji)性(xing),可(ke)能(neng)在(zai)兩(liang)個(ge)脈(mai)衝(chong)之(zhi)間(jian)會(hui)存(cun)在(zai)較(jiao)長(chang)時(shi)間(jian)的(de)本(ben)底(di)信(xin)號(hao),如(ru)果(guo)不(bu)加(jia)區(qu)別(bie)地(di)將(jiang)所(suo)有(you)信(xin)號(hao)都(dou)采(cai)集(ji)進(jin)計(ji)算(suan)機(ji),則(ze)一(yi)方(fang)麵(mian)會(hui)浪(lang)費(fei)大(da)量(liang)的(de)存(cun)儲(chu)資(zi)源(yuan),另(ling)一(yi)方(fang)麵(mian)會(hui)大(da)大(da)增(zeng)加(jia)計(ji)算(suan)機(ji)數(shu)據(ju)處(chu)理(li)的(de)負(fu)擔(dan),所(suo)以(yi)需(xu)要(yao)對(dui)數(shu)據(ju)采(cai)集(ji)進(jin)行(xing)閾(yu)值(zhi)觸(chu)發(fa),去(qu)除(chu)大(da)量(liang)的(de)無(wu)用(yong)本(ben)底(di)信(xin)號(hao),隻(zhi)采(cai)集(ji)有(you)用(yong)的(de)核(he)脈(mai)衝(chong)信(xin)號(hao),從(cong)而(er)為(wei)計(ji)算(suan)機(ji)爭(zheng)取(qu)寶(bao)貴(gui)的(de)數(shu)據(ju)處(chu)理(li)時(shi)間(jian)。其(qi)次(ci)還(hai)要(yao)求(qiu)數(shu)據(ju)采(cai)集(ji)卡(ka)具(ju)有(you)雙(shuang)緩(huan)衝(chong)存(cun)儲(chu)器(qi)結(jie)構(gou),從(cong)而(er)支(zhi)持(chi)數(shu)據(ju)的(de)連(lian)續(xu)采(cai)集(ji),當(dang)一(yi)個(ge)緩(huan)存(cun)被(bei)采(cai)集(ji)數(shu)據(ju)填(tian)滿(man)後(hou),等(deng)待(dai)計(ji)算(suan)機(ji)取(qu)走(zou),但(dan)數(shu)據(ju)采(cai)集(ji)並(bing)不(bu)中(zhong)斷(duan),采(cai)集(ji)數(shu)據(ju)被(bei)暫(zan)存(cun)到(dao)另(ling)一(yi)個(ge)緩(huan)存(cun)中(zhong),實(shi)現(xian)了(le)數(shu)據(ju)的(de)不(bu)間(jian)斷(duan)采(cai)集(ji),為(wei)數(shu)據(ju)采(cai)集(ji)和(he)數(shu)據(ju)處(chu)理(li)同(tong)步(bu)進(jin)行(xing)提(ti)供(gong)了(le)保(bao)證(zheng)。
而er數shu據ju處chu理li程cheng序xu的de核he心xin是shi要yao在zai所suo有you的de采cai樣yang點dian中zhong找zhao出chu真zhen正zheng的de脈mai衝chong峰feng值zhi,並bing在zai相xiang應ying幅fu度du對dui應ying的de道dao中zhong計ji數shu。經jing過guo長chang期qi實shi驗yan最zui終zhong選xuan用yong的de算suan法fa是shi逐zhu個ge比bi較jiao采cai樣yang點dian的de幅fu值zhi,如ru果guo出chu現xian連lian續xu兩liang個ge幅fu值zhi增zeng加jia後hou又you有you連lian續xu兩liang個ge幅fu值zhi減jian少shao則ze認ren為wei找zhao到dao了le一yi個ge真zhen正zheng的de脈mai衝chong峰feng值zhi。單dan道dao定ding標biao計ji數shu器qi的de功gong能neng分fen析xi和he軟ruan、硬件實現單道定標計數器是在規定的時間內或定標路一定的計數範圍內對經過前端放大、lvbochengxinghedianpingzhuanhuandehemaichongxinhaojinxingbutongweizhidejishuchuli,zuizhongdedaoliziqiangdudekongjianfenbu。yuduodaofudufenxiqixiangbi,dandaodingbiaojishuqidegongnengxiangduijiandan,tabuxuyaoduihemaichongdefudujinxingkedu,zhiyaohemaichongdefududadaoyidingdeyuzhijiunengbeizhenbieerjishu。yinci,zaixuanzeyingjianshiyingzhuyaokaolvtadejishugongneng。NI公司的PCI-6602是功能完善的一款高速計數卡,它最大的計數率能達到20M,具有100K、20M和80M三個可選的內時鍾,每個卡提供8gejishutongdao,nengmanzudandaodingbiaojishuqiduiduogeweizhijinxinghemaichongjishudeshijiyaoqiu,keyidadatigaochanpindexingjiabi。zairuanjianshejishang,zhongdianshidingshijishuhedingshujishudegongnengshixian。tongguoduiPCI-6602提供的基於LABVIEW的驅動程序的功能分析,知道了該卡能夠在OUT端口產生具有一定寬度的脈衝信號,脈衝寬度是以SOURCE端口的計數值作為基準,該計數值可以通過編程確定。如果將SOURCEduankoudexinhaoyuanshezhiweineishizhong,namezaiguidingdejishuzhineichanshengdemaichongkuandudeshijianjiangejiunengbeiqueding,liyongzhegegongnengbiannengchuangzaochudingshijishusuoxuyaodeshijianjizhun。
同理,如果將SOURCEduankoudexinhaoyuanshezhiweiwaibushurudemaichongxinhao,zezaiguidingdejishuzhineichanshengdemaichongkuandujiunengzuoweidingshujishusuoxuyaodedingbiaojizhun。tongshigaijishukahaijuyoumaikuanceliangdegongneng,takeyizaiqiGATE端口設置的脈衝寬度範圍內對SOURCE端口的脈衝信號進行計數,因此,隻要將前麵在OUT端口產生的具有一定寬度的脈衝引到計數通道的GATE端口,則就能完成單道定標計數器所要求的定時計數和定數計數功能。下圖是PCI-6602產生一定寬度的脈衝信號和進行脈寬測量的原理分析。前麵提到一個PCI-6602卡最多可以提供8個計數通道,而至少有一個通道要用來實現定時和定數功能,所以最終真正可以用到的隻有7個計數通道,如果實際需要多於7個計數通道,則必須增加計數卡,如何實現多卡的協調工作成為解決問題的關鍵。PCI-6602計數卡提供了內部RTSI總線用於多計數卡之間的互連,因此將用於實現定時和定數功能的通道的OUT端口的輸出信號引到RTSI總線上,所有用於計數的通道的GATE端口的輸入信號再從RTSI總線上引進,則一個卡上的定時和定數通道就能為所有用RTSI互連的計數卡提供定時和定數基準,從而順利完成計數通道的擴展,實現多卡的協調工作。目前用該方法已經實現了9個計數卡之間的互連,經過實驗驗證工作正常。
PCI-6602產生脈衝和脈寬測量的原理示意基於C/S網絡模式的虛擬儀器的設計與實現C/S(客戶機/服務器)wangluomoshishixiandeshikehujihefuwuqizhijiandedianduidiandeshujutongxin,keyizaifuwuqishangzhuangshangshujucaijiyingjianhexiangyingdeshujucaijichengxu,bingduishishixingyaoqiubijiaogaodesuanfajinxingchubuchuli。zaifuwuqiduanjianlifuwulianjie,bingbuduanzhentingkehujifasongdefuwuqingqiu,fuwuqichengxukegenjubutongdefuwuqingqiuzuochubutongdefuwuxiangying,manzukehujidefuwuyaoqiu。kehujiduanshouxianxuyaolianjiedaofuwuqichengxu,ranhougenjuxuyaofachubutongdefuwuqingqiu,rukongzhifuwuqiduanshujucaijideqiting、qingqiuchuansongyijingcaijidaobingbeichubuchulideshujudeng,zuihoukehujichengxuduidedaodeshujujinxinghouxuchuli,shixianshujudelixianfenxi。wangluomoshijiegoutubizhezaishiyanshishixianleduixuniduodaofudufenxiqihexunidandaodingbiaojishuqidejiyuC/S網wang絡luo模mo式shi的de異yi地di操cao作zuo,分fen別bie編bian寫xie了le相xiang應ying的de服fu務wu器qi端duan程cheng序xu和he客ke戶hu機ji端duan程cheng序xu,取qu得de了le理li想xiang的de控kong製zhi效xiao果guo。增zeng加jia了le偵zhen聽ting客ke戶hu程cheng序xu服fu務wu請qing求qiu的de子zi程cheng序xu,使shi得de服fu務wu器qi程cheng序xu一yi旦dan被bei運yun行xing,就jiu處chu於yu等deng待dai客ke戶hu程cheng序xu操cao作zuo請qing求qiu的de狀zhuang態tai,如ru果guo偵zhen聽ting到dao的de服fu務wu請qing求qiu為wei開kai始shi采cai集ji的de命ming令ling,則ze服fu務wu器qi程cheng序xu開kai始shi采cai集ji數shu據ju,並bing對dui數shu據ju進jin行xing尋xun找zhao峰feng值zhi的de初chu步bu處chu理li,同tong時shi繼ji續xu偵zhen聽ting停ting止zhi采cai集ji數shu據ju的de服fu務wu請qing求qiu。數shu據ju采cai集ji停ting止zhi後hou服fu務wu器qi程cheng序xu可ke接jie受shou客ke戶hu程cheng序xu要yao求qiu傳chuan送song幅fu度du譜pu數shu據ju的de請qing求qiu並bing把ba相xiang應ying的de數shu據ju傳chuan送song給gei客ke戶hu程cheng序xu始shi計ji數shu或huo停ting止zhi計ji數shu並bing向xiang客ke戶hu程cheng序xu發fa送song各ge通tong道dao的de計ji數shu結jie果guo等deng操cao作zuo。客ke戶hu程cheng序xu同tong樣yang實shi現xian的de是shi向xiang服fu務wu器qi端duan發fa送song不bu同tong的de服fu務wu請qing求qiu並bing對dui得de到dao的de計ji數shu結jie果guo進jin行xing文wen件jian管guan理li和he簡jian單dan分fen析xi的de功gong能neng。
在zai服fu務wu器qi上shang可ke以yi對dui網wang絡luo屬shu性xing進jin行xing設she置zhi,決jue定ding可ke以yi訪fang問wen的de客ke戶hu機ji以yi及ji它ta們men的de訪fang問wen權quan限xian,有you些xie客ke戶hu機ji可ke以yi設she置zhi為wei觀guan看kan並bing控kong製zhi服fu務wu器qi端duan的de應ying用yong程cheng序xu,有you些xie客ke戶hu機ji則ze隻zhi能neng觀guan看kan服fu務wu器qi端duan的de應ying用yong程cheng序xu。結jie論lun本ben文wen闡chan述shu的de虛xu擬ni多duo道dao幅fu度du分fen析xi器qi在zai低di頻pin核he脈mai衝chong的de幅fu度du分fen析xi中zhong取qu得de了le很hen好hao的de效xiao果guo,在zai用yong放fang射she源yuan為wei鈷gu60,探頭為高純鍺探測器的現場測試中,當采樣率設為13M,下閾設為0.3伏時采集1000秒miao得de到dao了le清qing晰xi的de雙shuang峰feng值zhi譜pu線xian。研yan製zhi的de虛xu擬ni單dan道dao定ding標biao計ji數shu器qi已yi經jing達da到dao實shi用yong標biao準zhun,現xian已yi被bei裝zhuang配pei到dao中zhong國guo原yuan子zi能neng科ke學xue研yan究jiu院yuan的de多duo個ge單dan位wei的de實shi驗yan室shi。中國糧油儀器網 http://98fo.cn/



