視頻監控系統的應用已非常廣泛，在道路、治安、森林防火、樓宇、工廠、商場等各行各業發揮其重要的作用。我國的平安城市治安監控系統，在全國各省市全面實施，并取得顯著的成果。龐大的監控系統中，前端的快球、攝像機設備，可以說是不計其數；而大型監控系統中前端攝像機的圖像必須通光纖傳輸才能實現大區域的監控圖像傳到監控中心。而其它行業的監控系統，同樣也用到大量的攝像機、視頻光端機傳輸等。

視頻監控系統的安裝和維護
　　視(shi)頻監控系統中，由于每個監控點位于不同的位置，需要花很多人力和時間在前端攝像機(快球)、傳輸設備安裝，以及傳輸線路輔設，如何快速檢測和維護設備和傳輸線路，節省維護成本是工程商們比較頭痛的問題。對于監控系統的維護，通常是對監控設備和傳輸線路進行檢修。視頻監控系統的監控中心設備如矩陣、視頻服務器、電視墻等，安裝在監控中心機房，設備集中在一個環境比較好的室內運行，監控中心設備出現故障的機率較小；而前端的攝像機、快球安裝在室外，視頻光端機安裝在室外配電箱中，設備要經受風吹雨打、夏天高溫和冬天低溫等惡劣的環境中工作，因此出現故障的機率比較高。對前端監控設備的維護，必須能夠測試攝像機圖(tu)像、快球的圖(tu)像、云臺控(kong)制、視頻光(guang)端(duan)機(ji)的光(guang)功率，以及使用萬用表對供電系(xi)統進行測(ce)試等，才能(neng)綜(zong)合解決前端(duan)設備可能(neng)出現在故(gu)障(zhang)。

　　1、攝像機維護
　　當監控中(zhong)心收(shou)不(bu)到圖(tu)(tu)像(xiang)(xiang)(xiang)時，工程人員首(shou)先要檢(jian)測(ce)攝(she)像(xiang)(xiang)(xiang)球(qiu)或球(qiu)機(ji)是否正(zheng)常。檢(jian)測(ce)攝(she)像(xiang)(xiang)(xiang)設備時，工程人員使用(yong)(yong)(yong)視頻(pin)監控綜合(he)測(ce)試(shi)儀表(biao)做三方面檢(jian)測(ce)工作：第(di)一，用(yong)(yong)(yong)儀表(biao)測(ce)試(shi)攝(she)像(xiang)(xiang)(xiang)機(ji)是否有圖(tu)(tu)像(xiang)(xiang)(xiang)，儀表(biao)3.5英寸的(de)(de)(de)彩色顯示(shi)屏能夠清晰顯示(shi)攝(she)像(xiang)(xiang)(xiang)機(ji)采集的(de)(de)(de)圖(tu)(tu)像(xiang)(xiang)(xiang)，如果儀表(biao)收(shou)不(bu)到圖(tu)(tu)像(xiang)(xiang)(xiang)或收(shou)到的(de)(de)(de)圖(tu)(tu)像(xiang)(xiang)(xiang)異常，說明攝(she)像(xiang)(xiang)(xiang)機(ji)存在(zai)故(gu)(gu)障；第(di)二，使用(yong)(yong)(yong)監控綜合(he)測(ce)試(shi)儀的(de)(de)(de)視頻(pin)信號(hao)衰減測(ce)量，測(ce)量攝(she)像(xiang)(xiang)(xiang)機(ji)的(de)(de)(de)視頻(pin)復和電平(ping)，正(zheng)常范圍是800-1000mV，電平(ping)太低會造(zao)成圖(tu)(tu)像(xiang)(xiang)(xiang)變暗，電平(ping)太高(gao)(gao)會造(zao)成虛影(ying)；第(di)三，使用(yong)(yong)(yong)儀表(biao)的(de)(de)(de)萬用(yong)(yong)(yong)表(biao)，測(ce)量攝(she)像(xiang)(xiang)(xiang)機(ji)的(de)(de)(de)變壓(ya)(ya)器供電是否正(zheng)常，一般(ban)變壓(ya)(ya)器輸(shu)(shu)出(chu)是直流12V，球(qiu)機(ji)的(de)(de)(de)變壓(ya)(ya)器輸(shu)(shu)出(chu)是交流24V，變壓(ya)(ya)器是監控系統中(zhong)故(gu)(gu)障率比較高(gao)(gao)的(de)(de)(de)配件(jian)。

　　2、云臺控制維護
　　安防監(jian)(jian)(jian)控(kong)(kong)系(xi)統中(zhong)，云(yun)臺或(huo)(huo)球機(ji)(ji)應(ying)用(yong)很廣泛(fan)，監(jian)(jian)(jian)控(kong)(kong)中(zhong)心工(gong)(gong)作人員(yuan)可以(yi)機(ji)(ji)動(dong)(dong)的(de)調整(zheng)攝像角(jiao)度，當云(yun)臺或(huo)(huo)球機(ji)(ji)不(bu)受(shou)控(kong)(kong)制時(shi)，或(huo)(huo)者在(zai)某個(ge)位(wei)置轉(zhuan)(zhuan)(zhuan)動(dong)(dong)不(bu)了(le)，工(gong)(gong)程(cheng)(cheng)人員(yuan)需要攜(xie)帶(dai)多(duo)功能(neng)鍵(jian)盤測(ce)(ce)試(shi)(shi)云(yun)臺或(huo)(huo)球機(ji)(ji)的(de)轉(zhuan)(zhuan)(zhuan)動(dong)(dong)是(shi)否正常。但是(shi)，不(bu)同的(de)云(yun)臺或(huo)(huo)球機(ji)(ji)廠家，他們擁有自己專用(yong)協(xie)議，工(gong)(gong)程(cheng)(cheng)商(shang)維護球機(ji)(ji)時(shi)就要帶(dai)相應(ying)的(de)多(duo)功能(neng)鍵(jian)盤測(ce)(ce)試(shi)(shi)，有可能(neng)要帶(dai)多(duo)個(ge)鍵(jian)盤以(yi)備測(ce)(ce)試(shi)(shi)不(bu)同的(de)球機(ji)(ji)使用(yong)。工(gong)(gong)程(cheng)(cheng)人員(yuan)使用(yong)視頻監(jian)(jian)(jian)控(kong)(kong)綜(zong)合測(ce)(ce)試(shi)(shi)儀(yi)很好(hao)的(de)解決這個(ge)問(wen)題(ti)，因為它內嵌入了(le)Pelco-D/P、BOSCH等三十多(duo)種協(xie)議，和專用(yong)于測(ce)(ce)試(shi)(shi)云(yun)臺轉(zhuan)(zhuan)(zhuan)動(dong)(dong)的(de)云(yun)臺續(xu)轉(zhuan)(zhuan)(zhuan)測(ce)(ce)試(shi)(shi)功能(neng)，工(gong)(gong)程(cheng)(cheng)人員(yuan)可以(yi)通過儀(yi)表操作云(yun)臺不(bu)停轉(zhuan)(zhuan)(zhuan)動(dong)(dong)，觀察云(yun)臺轉(zhuan)(zhuan)(zhuan)動(dong)(dong)時(shi)是(shi)否有卡位(wei)的(de)現(xian)象。

　　3、視頻光端維護
　　視(shi)頻光(guang)(guang)端(duan)(duan)(duan)機(ji)(ji)分為發(fa)射(she)端(duan)(duan)(duan)設備和接(jie)(jie)收端(duan)(duan)(duan)設備，發(fa)射(she)端(duan)(duan)(duan)設備和攝像(xiang)機(ji)(ji)一(yi)樣置于室外，工(gong)程人員(yuan)通常是(shi)對(dui)(dui)發(fa)射(she)端(duan)(duan)(duan)設備過行(xing)維(wei)護(hu)測(ce)試(shi)。對(dui)(dui)于光(guang)(guang)端(duan)(duan)(duan)機(ji)(ji)的(de)檢修工(gong)作，分三個步驟進行(xing)測(ce)試(shi)。第一(yi)，用(yong)視(shi)頻監控(kong)(kong)綜合(he)測(ce)試(shi)儀的(de)萬用(yong)表測(ce)量光(guang)(guang)端(duan)(duan)(duan)機(ji)(ji)的(de)供(gong)電(dian)是(shi)否(fou)正(zheng)常，一(yi)般電(dian)源輸入是(shi)直流5V；第二，測(ce)量光(guang)(guang)端(duan)(duan)(duan)機(ji)(ji)的(de)光(guang)(guang)纖(xian)輸出功率是(shi)否(fou)正(zheng)常，發(fa)射(she)端(duan)(duan)(duan)發(fa)射(she)波長是(shi)1310n接(jie)(jie)收波長1510n，20KM的(de)光(guang)(guang)端(duan)(duan)(duan)機(ji)(ji)一(yi)般發(fa)射(she)功率是(shi)-9dBm左右；第三，測(ce)試(shi)光(guang)(guang)端(duan)(duan)(duan)機(ji)(ji)的(de)視(shi)頻端(duan)(duan)(duan)口(kou)和RS485/RS232通信是(shi)否(fou)正(zheng)常。監控(kong)(kong)綜合(he)測(ce)試(shi)儀發(fa)送標準彩****型條圖像(xiang)信號(hao)到(dao)視(shi)頻光(guang)(guang)端(duan)(duan)(duan)機(ji)(ji)，監控(kong)(kong)中心收到(dao)視(shi)頻光(guang)(guang)端(duan)(duan)(duan)機(ji)(ji)送來的(de)測(ce)試(shi)彩色條，說(shuo)明視(shi)頻傳輸部份正(zheng)常；用(yong)儀表的(de)RS485/RS232數據捕捉功能(neng)接(jie)(jie)收光(guang)(guang)端(duan)(duan)(duan)機(ji)(ji)的(de)控(kong)(kong)制信號(hao)，如果接(jie)(jie)收到(dao)監控(kong)(kong)中心發(fa)送過來的(de)控(kong)(kong)制代碼(ma)，說(shuo)明光(guang)(guang)端(duan)(duan)(duan)機(ji)(ji)的(de)RS485/RS232通信傳輸正(zheng)常。

　　4、BNC同軸電纜傳輸維護
　　目(mu)前的(de)視(shi)(shi)頻監(jian)控系統(tong)(tong)，傳統(tong)(tong)的(de)模擬(ni)圖像占主(zhu)導地位，IP數字攝像由于兼容性(xing)等問題(ti)，暫(zan)時未(wei)來(lai)得到普及。一般小(xiao)區(qu)域的(de)監(jian)控系統(tong)(tong)如工廠(chang)、樓(lou)宇，直接采用(yong)(yong)BNC同軸(zhou)(zhou)電(dian)(dian)(dian)纜傳輸(shu)圖像，BNC同軸(zhou)(zhou)電(dian)(dian)(dian)纜由于抗干擾(rao)性(xing)弱(ruo)，而且每條BNC線(xian)纜只能傳輸(shu)一路視(shi)(shi)頻，但由于監(jian)控區(qu)域小(xiao)，采用(yong)(yong)同軸(zhou)(zhou)電(dian)(dian)(dian)纜傳輸(shu)相對成(cheng)本較低，BNC同軸(zhou)(zhou)電(dian)(dian)(dian)纜得以普遍使用(yong)(yong)。BNC線(xian)纜由于老化、人為損壞等原因，造成(cheng)視(shi)(shi)頻圖像質(zhi)量(liang)下降甚至中斷，在維護工作(zuo)中通常需(xu)要檢測BNC線(xian)纜是(shi)否有(you)問題(ti)。
　　工(gong)(gong)程(cheng)人(ren)員(yuan)對線(xian)纜(lan)(lan)維護(hu)時，使(shi)用綜(zong)合測(ce)(ce)(ce)試儀(yi)做三個步驟(zou)(zou)的(de)工(gong)(gong)作(zuo)，第一，在攝像機端，將BNC線(xian)纜(lan)(lan)接入儀(yi)表，使(shi)用儀(yi)表的(de)圖像發(fa)生(sheng)器發(fa)送標(biao)準彩(cai)****型條，正(zheng)常(chang)(chang)情況下，監(jian)控中心的(de)監(jian)視(shi)器應該收到(dao)同樣的(de)彩(cai)****型條，這個步驟(zou)(zou)判斷BNC線(xian)是(shi)否斷開，監(jian)控中心收到(dao)圖像色彩(cai)是(shi)否正(zheng)常(chang)(chang)；第二(er)，在監(jian)控中心，使(shi)用儀(yi)表的(de)視(shi)頻信(xin)號衰(shuai)減測(ce)(ce)(ce)量功能，測(ce)(ce)(ce)量視(shi)頻復和電平(ping)經過(guo)BNC線(xian)纜(lan)(lan)傳輸后是(shi)否衰(shuai)減過(guo)大，一般正(zheng)常(chang)(chang)是(shi)800-1000mV，衰(shuai)減過(guo)大會造成圖像抖動(dong)、圖像變暗等(deng)現象(xiang)。第三，如果BNC線(xian)纜(lan)(lan)中間斷開，因為BNC線(xian)纜(lan)(lan)埋在線(xian)槽里(li)，工(gong)(gong)程(cheng)人(ren)員(yuan)沒有(you)測(ce)(ce)(ce)試工(gong)(gong)具(ju)要找(zhao)出(chu)故(gu)障點(dian)非常(chang)(chang)困難，使(shi)用綜(zong)合測(ce)(ce)(ce)試儀(yi)表的(de)測(ce)(ce)(ce)線(xian)功能，儀(yi)表發(fa)射信(xin)號并測(ce)(ce)(ce)量出(chu)大概(gai)斷點(dian)位置(zhi)，為工(gong)(gong)程(cheng)人(ren)員(yuan)馬上找(zhao)到(dao)斷點(dian)位置(zhi)，大大提高工(gong)(gong)作(zuo)效率(lv)。

　　5、光纖傳輸維護
　　光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)傳輸(shu)(shu)(shu)具(ju)有(you)容量(liang)(liang)大(da)、高速率、高穩(wen)定(ding)(ding)性等(deng)(deng)(deng)特點(dian)(dian)，視頻監控系統(tong)(tong)越來(lai)越多(duo)采用(yong)視頻光(guang)(guang)(guang)(guang)(guang)(guang)端(duan)機(ji)、光(guang)(guang)(guang)(guang)(guang)(guang)收發(fa)器等(deng)(deng)(deng)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)設備(bei)來(lai)傳送視頻圖像(xiang)和控制(zhi)信(xin)號。高速公(gong)路監控、平(ping)安城市監控等(deng)(deng)(deng)大(da)規(gui)(gui)型的(de)(de)(de)(de)(de)(de)監控系統(tong)(tong)采用(yong)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)傳輸(shu)(shu)(shu)來(lai)實現高穩(wen)定(ding)(ding)的(de)(de)(de)(de)(de)(de)視頻傳輸(shu)(shu)(shu)，隨著光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)通(tong)信(xin)技術發(fa)展，視頻光(guang)(guang)(guang)(guang)(guang)(guang)端(duan)和光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)線纜(lan)價格越來(lai)越低，視頻監控系統(tong)(tong)采用(yong)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)傳輸(shu)(shu)(shu)已經(jing)(jing)非常普及。光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)傳輸(shu)(shu)(shu)通(tong)常是應用(yong)在幾百米到一百公(gong)里(li)之間信(xin)號傳輸(shu)(shu)(shu)，對光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)線纜(lan)進(jin)行檢測(ce)(ce)(ce)也(ye)是必不可(ke)少的(de)(de)(de)(de)(de)(de)環節。對于光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)的(de)(de)(de)(de)(de)(de)維(wei)護，工(gong)程人員必須使(shi)用(yong)專業的(de)(de)(de)(de)(de)(de)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)測(ce)(ce)(ce)試儀表(biao)，如光(guang)(guang)(guang)(guang)(guang)(guang)源、光(guang)(guang)(guang)(guang)(guang)(guang)功(gong)率計(ji)、OTDR等(deng)(deng)(deng)。穩(wen)定(ding)(ding)光(guang)(guang)(guang)(guang)(guang)(guang)源是專門用(yong)來(lai)發(fa)出高穩(wen)定(ding)(ding)功(gong)率值的(de)(de)(de)(de)(de)(de)雷射光(guang)(guang)(guang)(guang)(guang)(guang)，雷射光(guang)(guang)(guang)(guang)(guang)(guang)經(jing)(jing)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)傳輸(shu)(shu)(shu)后(hou)有(you)一定(ding)(ding)的(de)(de)(de)(de)(de)(de)衰減，通(tong)過光(guang)(guang)(guang)(guang)(guang)(guang)功(gong)率計(ji)測(ce)(ce)(ce)量(liang)(liang)經(jing)(jing)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)傳輸(shu)(shu)(shu)后(hou)的(de)(de)(de)(de)(de)(de)功(gong)率值，計(ji)算(suan)(suan)出光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)損耗值是多(duo)少dB。測(ce)(ce)(ce)量(liang)(liang)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)耗時，必須用(yong)光(guang)(guang)(guang)(guang)(guang)(guang)源和光(guang)(guang)(guang)(guang)(guang)(guang)功(gong)率計(ji)配對使(shi)用(yong)，才能(neng)準備(bei)計(ji)算(suan)(suan)出光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)損耗；而(er)OTDR是用(yong)來(lai)測(ce)(ce)(ce)量(liang)(liang)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)的(de)(de)(de)(de)(de)(de)斷(duan)點(dian)(dian)位(wei)置的(de)(de)(de)(de)(de)(de)儀器，它(ta)探測(ce)(ce)(ce)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)大(da)概在多(duo)少公(gong)里(li)處斷(duan)開，但OTDR的(de)(de)(de)(de)(de)(de)造價太(tai)高，規(gui)(gui)模(mo)(mo)較小的(de)(de)(de)(de)(de)(de)工(gong)程商(shang)可(ke)以采用(yong)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)尋障儀來(lai)測(ce)(ce)(ce)量(liang)(liang)斷(duan)點(dian)(dian)位(wei)置。對于小規(gui)(gui)模(mo)(mo)的(de)(de)(de)(de)(de)(de)工(gong)程商(shang)，最(zui)需要的(de)(de)(de)(de)(de)(de)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)測(ce)(ce)(ce)量(liang)(liang)工(gong)具(ju)就是光(guang)(guang)(guang)(guang)(guang)(guang)功(gong)率計(ji)，因為長距(ju)離的(de)(de)(de)(de)(de)(de)光(guang)(guang)(guang)(guang)(guang)(guang)纜(lan)通(tong)常是電信(xin)運營商(shang)或廣電系統(tong)(tong)進(jin)維(wei)護，小規(gui)(gui)模(mo)(mo)的(de)(de)(de)(de)(de)(de)工(gong)程商(shang)只需要測(ce)(ce)(ce)量(liang)(liang)光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)設備(bei)的(de)(de)(de)(de)(de)(de)功(gong)率和光(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)(xian)(xian)(xian)損耗，找出問題所在就足(zu)夠了。
　　維(wei)護光(guang)(guang)(guang)纖(xian)時，工程人員使用(yong)監控綜合測(ce)(ce)試儀的(de)光(guang)(guang)(guang)功(gong)率(lv)測(ce)(ce)量(liang)功(gong)能，切換(huan)到相對(dui)應(ying)的(de)波長(chang)對(dui)多模、單(dan)模的(de)光(guang)(guang)(guang)纖(xian)進行(xing)測(ce)(ce)量(liang)，光(guang)(guang)(guang)纖(xian)連接的(de)光(guang)(guang)(guang)通信設備(如視頻光(guang)(guang)(guang)端機、光(guang)(guang)(guang)收發(fa)器)正常(chang)情(qing)況下會(hui)發(fa)射光(guang)(guang)(guang)信號，如果(guo)儀表接收不到光(guang)(guang)(guang)信號時，顯示-70dBm，說明光(guang)(guang)(guang)纖(xian)不通，需要(yao)檢查光(guang)(guang)(guang)纖(xian)跳線、光(guang)(guang)(guang)纜(lan)是否斷開或損壞。