視頻監控系統的安裝與維護

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(qi)數；而大(da)(da)型監(jian)(jian)控系統(tong)中前(qian)端攝像(xiang)機的(de)(de)圖像(xiang)必須通(tong)光(guang)纖傳輸才(cai)能實現大(da)(da)區域的(de)(de)監(jian)(jian)控圖像(xiang)傳到(dao)監(jian)(jian)控中心。而其(qi)它行業的(de)(de)監(jian)(jian)控系統(tong)，同樣也用到(dao)大(da)(da)量的(de)(de)攝像(xiang)機、視頻光(guang)端機傳輸等。

視頻監控系統(tong)的安裝和(he)維(wei)護

視頻監控系統中，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(dian)視(shi)(shi)墻(qiang)等，安(an)裝在監控(kong)中(zhong)(zhong)(zhong)心機(ji)(ji)(ji)房(fang)，設(she)備(bei)集(ji)中(zhong)(zhong)(zhong)在一個環境(jing)比較(jiao)好的室內運行，監控(kong)中(zhong)(zhong)(zhong)心設(she)備(bei)出現(xian)(xian)故(gu)(gu)障(zhang)的機(ji)(ji)(ji)率(lv)較(jiao)小(xiao)；而前(qian)端(duan)的攝像(xiang)機(ji)(ji)(ji)、快球(qiu)安(an)裝在室外，視(shi)(shi)頻光(guang)端(duan)機(ji)(ji)(ji)安(an)裝在室外配電(dian)箱(xiang)中(zhong)(zhong)(zhong)，設(she)備(bei)要經受風(feng)吹(chui)雨(yu)打(da)、夏天(tian)高溫和冬天(tian)低(di)溫等惡劣的環境(jing)中(zhong)(zhong)(zhong)工作，因此出現(xian)(xian)故(gu)(gu)障(zhang)的機(ji)(ji)(ji)率(lv)比較(jiao)高。對(dui)前(qian)端(duan)監控(kong)設(she)備(bei)的維護，必須(xu)能夠測試(shi)攝像(xiang)機(ji)(ji)(ji)圖像(xiang)、快球(qiu)的圖像(xiang)、云臺控(kong)制、視(shi)(shi)頻光(guang)端(duan)機(ji)(ji)(ji)的光(guang)功(gong)率(lv)，以(yi)及使用萬用表對(dui)供電(dian)系統進行測試(shi)等，才(cai)能綜合(he)解決前(qian)端(duan)設(she)備(bei)可能出現(xian)(xian)在故(gu)(gu)障(zhang)。

1、攝像機維護

當監控(kong)中(zhong)心收(shou)不到圖(tu)像(xiang)(xiang)(xiang)(xiang)(xiang)時(shi)，工程(cheng)人員首先要檢測攝(she)(she)像(xiang)(xiang)(xiang)(xiang)(xiang)球或球機(ji)是(shi)(shi)否正(zheng)常(chang)。檢測攝(she)(she)像(xiang)(xiang)(xiang)(xiang)(xiang)設備時(shi)，工程(cheng)人員使(shi)用(yong)(yong)(yong)視頻監控(kong)綜合測試儀(yi)表(biao)做(zuo)三方(fang)面檢測工作：第一，用(yong)(yong)(yong)儀(yi)表(biao)測試攝(she)(she)像(xiang)(xiang)(xiang)(xiang)(xiang)機(ji)是(shi)(shi)否有圖(tu)像(xiang)(xiang)(xiang)(xiang)(xiang)，儀(yi)表(biao)3.5英寸(cun)的(de)彩色顯示(shi)屏能夠清晰(xi)顯示(shi)攝(she)(she)像(xiang)(xiang)(xiang)(xiang)(xiang)機(ji)采集的(de)圖(tu)像(xiang)(xiang)(xiang)(xiang)(xiang)，如果儀(yi)表(biao)收(shou)不到圖(tu)像(xiang)(xiang)(xiang)(xiang)(xiang)或收(shou)到的(de)圖(tu)像(xiang)(xiang)(xiang)(xiang)(xiang)異常(chang)，說明(ming)攝(she)(she)像(xiang)(xiang)(xiang)(xiang)(xiang)機(ji)存在故障；第二，使(shi)用(yong)(yong)(yong)監控(kong)綜合測試儀(yi)的(de)視頻信(xin)號衰減測量，測量攝(she)(she)像(xiang)(xiang)(xiang)(xiang)(xiang)機(ji)的(de)視頻復和電(dian)平(ping)(ping)，正(zheng)常(chang)范圍是(shi)(shi)800-1000mV，電(dian)平(ping)(ping)太(tai)低會造成圖(tu)像(xiang)(xiang)(xiang)(xiang)(xiang)變(bian)(bian)暗，電(dian)平(ping)(ping)太(tai)高會造成虛影；第三，使(shi)用(yong)(yong)(yong)儀(yi)表(biao)的(de)萬(wan)用(yong)(yong)(yong)表(biao)，測量攝(she)(she)像(xiang)(xiang)(xiang)(xiang)(xiang)機(ji)的(de)變(bian)(bian)壓(ya)器(qi)(qi)(qi)供電(dian)是(shi)(shi)否正(zheng)常(chang)，一般(ban)變(bian)(bian)壓(ya)器(qi)(qi)(qi)輸出(chu)(chu)是(shi)(shi)直流12V，球機(ji)的(de)變(bian)(bian)壓(ya)器(qi)(qi)(qi)輸出(chu)(chu)是(shi)(shi)交流24V，變(bian)(bian)壓(ya)器(qi)(qi)(qi)是(shi)(shi)監控(kong)系統中(zhong)故障率比較高的(de)配件。

2、云臺控制維護

安防監控系統中，云(yun)(yun)臺(tai)(tai)或(huo)球(qiu)(qiu)機(ji)(ji)應(ying)用(yong)很廣泛，監(jian)(jian)控(kong)中心工作(zuo)人(ren)(ren)員可(ke)以機(ji)(ji)動(dong)(dong)的(de)(de)調整攝(she)像(xiang)角度(du)，當云(yun)(yun)臺(tai)(tai)或(huo)球(qiu)(qiu)機(ji)(ji)不受控(kong)制時(shi)，或(huo)者在(zai)某個(ge)位置轉(zhuan)(zhuan)動(dong)(dong)不了(le)(le)，工程(cheng)人(ren)(ren)員需要攜帶多(duo)功(gong)能(neng)鍵(jian)盤(pan)測(ce)(ce)試(shi)(shi)云(yun)(yun)臺(tai)(tai)或(huo)球(qiu)(qiu)機(ji)(ji)的(de)(de)轉(zhuan)(zhuan)動(dong)(dong)是否正常。但(dan)是，不同的(de)(de)云(yun)(yun)臺(tai)(tai)或(huo)球(qiu)(qiu)機(ji)(ji)廠家，他們擁(yong)有(you)自(zi)己專(zhuan)(zhuan)用(yong)協議(yi)，工程(cheng)商維護(hu)球(qiu)(qiu)機(ji)(ji)時(shi)就要帶相應(ying)的(de)(de)多(duo)功(gong)能(neng)鍵(jian)盤(pan)測(ce)(ce)試(shi)(shi)，有(you)可(ke)能(neng)要帶多(duo)個(ge)鍵(jian)盤(pan)以備(bei)測(ce)(ce)試(shi)(shi)不同的(de)(de)球(qiu)(qiu)機(ji)(ji)使(shi)用(yong)。工程(cheng)人(ren)(ren)員使(shi)用(yong)視頻監(jian)(jian)控(kong)綜(zong)合測(ce)(ce)試(shi)(shi)儀很好的(de)(de)解決這個(ge)問題，因為它(ta)內嵌入了(le)(le)Pelco-D/P、BOSCH等三十(shi)多(duo)種協議(yi)，和專(zhuan)(zhuan)用(yong)于(yu)測(ce)(ce)試(shi)(shi)云(yun)(yun)臺(tai)(tai)轉(zhuan)(zhuan)動(dong)(dong)的(de)(de)云(yun)(yun)臺(tai)(tai)續(xu)轉(zhuan)(zhuan)測(ce)(ce)試(shi)(shi)功(gong)能(neng)，工程(cheng)人(ren)(ren)員可(ke)以通過儀表(biao)操作(zuo)云(yun)(yun)臺(tai)(tai)不停轉(zhuan)(zhuan)動(dong)(dong)，觀察云(yun)(yun)臺(tai)(tai)轉(zhuan)(zhuan)動(dong)(dong)時(shi)是否有(you)卡位的(de)(de)現象。

3、視頻光端維護

視(shi)頻(pin)光(guang)端(duan)(duan)(duan)(duan)(duan)(duan)機(ji)分為發(fa)射端(duan)(duan)(duan)(duan)(duan)(duan)設備和(he)接(jie)收端(duan)(duan)(duan)(duan)(duan)(duan)設備，發(fa)射端(duan)(duan)(duan)(duan)(duan)(duan)設備和(he)攝像(xiang)機(ji)一樣置于(yu)室外，工程人員通常(chang)是(shi)(shi)(shi)對發(fa)射端(duan)(duan)(duan)(duan)(duan)(duan)設備過(guo)(guo)行(xing)維護測(ce)(ce)試。對于(yu)光(guang)端(duan)(duan)(duan)(duan)(duan)(duan)機(ji)的(de)(de)(de)(de)檢(jian)修工作(zuo)，分三個步驟進行(xing)測(ce)(ce)試。第一，用視(shi)頻(pin)監(jian)控綜合(he)測(ce)(ce)試儀(yi)的(de)(de)(de)(de)萬用表測(ce)(ce)量光(guang)端(duan)(duan)(duan)(duan)(duan)(duan)機(ji)的(de)(de)(de)(de)供電是(shi)(shi)(shi)否正(zheng)常(chang)，一般(ban)電源(yuan)輸入是(shi)(shi)(shi)直(zhi)流5V；第二，測(ce)(ce)量光(guang)端(duan)(duan)(duan)(duan)(duan)(duan)機(ji)的(de)(de)(de)(de)光(guang)纖輸出(chu)功(gong)(gong)率是(shi)(shi)(shi)否正(zheng)常(chang)，發(fa)射端(duan)(duan)(duan)(duan)(duan)(duan)發(fa)射波長是(shi)(shi)(shi)1310n接(jie)收波長1510n，20KM的(de)(de)(de)(de)光(guang)端(duan)(duan)(duan)(duan)(duan)(duan)機(ji)一般(ban)發(fa)射功(gong)(gong)率是(shi)(shi)(shi)-9dBm左(zuo)右；第三，測(ce)(ce)試光(guang)端(duan)(duan)(duan)(duan)(duan)(duan)機(ji)的(de)(de)(de)(de)視(shi)頻(pin)端(duan)(duan)(duan)(duan)(duan)(duan)口和(he)RS485/RS232通信(xin)是(shi)(shi)(shi)否正(zheng)常(chang)。監(jian)控綜合(he)測(ce)(ce)試儀(yi)發(fa)送標準彩****型條(tiao)圖像(xiang)信(xin)號(hao)(hao)到(dao)視(shi)頻(pin)光(guang)端(duan)(duan)(duan)(duan)(duan)(duan)機(ji)，監(jian)控中心收到(dao)視(shi)頻(pin)光(guang)端(duan)(duan)(duan)(duan)(duan)(duan)機(ji)送來的(de)(de)(de)(de)測(ce)(ce)試彩色條(tiao)，說(shuo)明(ming)視(shi)頻(pin)傳輸部份正(zheng)常(chang)；用儀(yi)表的(de)(de)(de)(de)RS485/RS232數據捕捉功(gong)(gong)能接(jie)收光(guang)端(duan)(duan)(duan)(duan)(duan)(duan)機(ji)的(de)(de)(de)(de)控制(zhi)信(xin)號(hao)(hao)，如(ru)果接(jie)收到(dao)監(jian)控中心發(fa)送過(guo)(guo)來的(de)(de)(de)(de)控制(zhi)代碼，說(shuo)明(ming)光(guang)端(duan)(duan)(duan)(duan)(duan)(duan)機(ji)的(de)(de)(de)(de)RS485/RS232通信(xin)傳輸正(zheng)常(chang)。

4、BNC同軸電纜傳輸維護

目前的(de)(de)視頻監控(kong)系統，傳統的(de)(de)模擬圖像占(zhan)主導地位(wei)，IP數(shu)字(zi)攝像由(you)于(yu)兼容性(xing)等(deng)問題(ti)，暫時未來得(de)到普及。一般小(xiao)區域的(de)(de)監控(kong)系統如工(gong)廠、樓宇，直(zhi)接采(cai)用(yong)BNC同(tong)軸電(dian)纜傳輸(shu)(shu)圖像，BNC同(tong)軸電(dian)纜由(you)于(yu)抗干擾性(xing)弱，而且每條BNC線纜只能傳輸(shu)(shu)一路(lu)視頻，但由(you)于(yu)監控(kong)區域小(xiao)，采(cai)用(yong)同(tong)軸電(dian)纜傳輸(shu)(shu)相對成本較低，BNC同(tong)軸電(dian)纜得(de)以普遍(bian)使用(yong)。BNC線纜由(you)于(yu)老(lao)化、人為(wei)損壞(huai)等(deng)原(yuan)因，造成視頻圖像質量下降甚至中(zhong)(zhong)斷，在(zai)維護工(gong)作(zuo)中(zhong)(zhong)通常需要檢測BNC線纜是否有問題(ti)。

工(gong)程人員對線(xian)(xian)纜(lan)維護(hu)時，使(shi)用(yong)綜合測(ce)試(shi)儀(yi)(yi)做三個步(bu)(bu)驟(zou)的(de)(de)工(gong)作，第(di)一(yi)，在(zai)(zai)攝像機端(duan)，將BNC線(xian)(xian)纜(lan)接(jie)入(ru)儀(yi)(yi)表，使(shi)用(yong)儀(yi)(yi)表的(de)(de)圖像發(fa)生(sheng)器發(fa)送標(biao)準彩****型條，正常(chang)情況下，監(jian)控(kong)中(zhong)心的(de)(de)監(jian)視(shi)器應該收(shou)到同(tong)樣的(de)(de)彩****型條，這個步(bu)(bu)驟(zou)判斷BNC線(xian)(xian)是否(fou)斷開(kai)，監(jian)控(kong)中(zhong)心收(shou)到圖像色彩是否(fou)正常(chang)；第(di)二，在(zai)(zai)監(jian)控(kong)中(zhong)心，使(shi)用(yong)儀(yi)(yi)表的(de)(de)視(shi)頻(pin)信號衰減測(ce)量功(gong)能，測(ce)量視(shi)頻(pin)復和電平經過(guo)BNC線(xian)(xian)纜(lan)傳輸(shu)后是否(fou)衰減過(guo)大(da)，一(yi)般(ban)正常(chang)是800-1000mV，衰減過(guo)大(da)會造成圖像抖動(dong)、圖像變暗等現象(xiang)。第(di)三，如果BNC線(xian)(xian)纜(lan)中(zhong)間斷開(kai)，因為BNC線(xian)(xian)纜(lan)埋在(zai)(zai)線(xian)(xian)槽里，工(gong)程人員沒有測(ce)試(shi)工(gong)具要(yao)找出故障點非常(chang)困難，使(shi)用(yong)綜合測(ce)試(shi)儀(yi)(yi)表的(de)(de)測(ce)線(xian)(xian)功(gong)能，儀(yi)(yi)表發(fa)射信號并(bing)測(ce)量出大(da)概斷點位置，為工(gong)程人員馬上找到斷點位置，大(da)大(da)提高工(gong)作效(xiao)率。

5、光纖傳輸維護

光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)傳輸(shu)(shu)具有容量(liang)(liang)(liang)大(da)(da)、高(gao)速率(lv)(lv)、高(gao)穩(wen)定性等(deng)(deng)特點，視(shi)(shi)頻監(jian)(jian)控系(xi)(xi)統(tong)越(yue)(yue)來(lai)(lai)(lai)越(yue)(yue)多(duo)(duo)采(cai)用(yong)(yong)(yong)視(shi)(shi)頻光(guang)(guang)(guang)(guang)(guang)(guang)(guang)端機、光(guang)(guang)(guang)(guang)(guang)(guang)(guang)收(shou)發器等(deng)(deng)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)設備來(lai)(lai)(lai)傳送視(shi)(shi)頻圖像和(he)控制信(xin)(xin)(xin)號。高(gao)速公(gong)路監(jian)(jian)控、平安城市監(jian)(jian)控等(deng)(deng)大(da)(da)規型的(de)(de)監(jian)(jian)控系(xi)(xi)統(tong)采(cai)用(yong)(yong)(yong)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)傳輸(shu)(shu)來(lai)(lai)(lai)實(shi)現高(gao)穩(wen)定的(de)(de)視(shi)(shi)頻傳輸(shu)(shu)，隨著光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)通信(xin)(xin)(xin)技(ji)術發展(zhan)，視(shi)(shi)頻光(guang)(guang)(guang)(guang)(guang)(guang)(guang)端和(he)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)線纜價格(ge)越(yue)(yue)來(lai)(lai)(lai)越(yue)(yue)低，視(shi)(shi)頻監(jian)(jian)控系(xi)(xi)統(tong)采(cai)用(yong)(yong)(yong)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)傳輸(shu)(shu)已經非常普(pu)及。光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)傳輸(shu)(shu)通常是(shi)應用(yong)(yong)(yong)在(zai)幾百(bai)米到(dao)一百(bai)公(gong)里(li)之間信(xin)(xin)(xin)號傳輸(shu)(shu)，對(dui)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)線纜進行檢測也是(shi)必不可(ke)少的(de)(de)環節。對(dui)于光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)的(de)(de)維(wei)護，工(gong)(gong)(gong)程人員(yuan)必須使用(yong)(yong)(yong)專業的(de)(de)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)測試儀表，如(ru)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)源、光(guang)(guang)(guang)(guang)(guang)(guang)(guang)功(gong)率(lv)(lv)計(ji)(ji)、OTDR等(deng)(deng)。穩(wen)定光(guang)(guang)(guang)(guang)(guang)(guang)(guang)源是(shi)專門用(yong)(yong)(yong)來(lai)(lai)(lai)發出高(gao)穩(wen)定功(gong)率(lv)(lv)值的(de)(de)雷射光(guang)(guang)(guang)(guang)(guang)(guang)(guang)，雷射光(guang)(guang)(guang)(guang)(guang)(guang)(guang)經光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)傳輸(shu)(shu)后有一定的(de)(de)衰減(jian)，通過光(guang)(guang)(guang)(guang)(guang)(guang)(guang)功(gong)率(lv)(lv)計(ji)(ji)測量(liang)(liang)(liang)經光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)傳輸(shu)(shu)后的(de)(de)功(gong)率(lv)(lv)值，計(ji)(ji)算(suan)出光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)損(sun)耗值是(shi)多(duo)(duo)少dB。測量(liang)(liang)(liang)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)耗時，必須用(yong)(yong)(yong)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)源和(he)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)功(gong)率(lv)(lv)計(ji)(ji)配對(dui)使用(yong)(yong)(yong)，才能準(zhun)備計(ji)(ji)算(suan)出光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)損(sun)耗；而OTDR是(shi)用(yong)(yong)(yong)來(lai)(lai)(lai)測量(liang)(liang)(liang)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)的(de)(de)斷點位(wei)置的(de)(de)儀器，它探測光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)大(da)(da)概在(zai)多(duo)(duo)少公(gong)里(li)處斷開，但OTDR的(de)(de)造價太高(gao)，規模(mo)較小的(de)(de)工(gong)(gong)(gong)程商可(ke)以采(cai)用(yong)(yong)(yong)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)尋障儀來(lai)(lai)(lai)測量(liang)(liang)(liang)斷點位(wei)置。對(dui)于小規模(mo)的(de)(de)工(gong)(gong)(gong)程商，最(zui)需(xu)(xu)要的(de)(de)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)測量(liang)(liang)(liang)工(gong)(gong)(gong)具就(jiu)(jiu)是(shi)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)功(gong)率(lv)(lv)計(ji)(ji)，因(yin)為(wei)長(chang)距離的(de)(de)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纜通常是(shi)電信(xin)(xin)(xin)運營商或廣電系(xi)(xi)統(tong)進維(wei)護，小規模(mo)的(de)(de)工(gong)(gong)(gong)程商只需(xu)(xu)要測量(liang)(liang)(liang)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)設備的(de)(de)功(gong)率(lv)(lv)和(he)光(guang)(guang)(guang)(guang)(guang)(guang)(guang)纖(xian)損(sun)耗，找出問題所在(zai)就(jiu)(jiu)足夠(gou)了(le)。

維護光(guang)(guang)(guang)(guang)纖時，工(gong)程人員使用監控綜合測試儀的(de)光(guang)(guang)(guang)(guang)功率(lv)測量(liang)功能，切換到(dao)相對(dui)應的(de)波長對(dui)多模、單模的(de)光(guang)(guang)(guang)(guang)纖進行測量(liang)，光(guang)(guang)(guang)(guang)纖連(lian)接的(de)光(guang)(guang)(guang)(guang)通信設備(如視頻(pin)光(guang)(guang)(guang)(guang)端機、光(guang)(guang)(guang)(guang)收發(fa)器)正(zheng)常情況下(xia)會發(fa)射光(guang)(guang)(guang)(guang)信號，如果儀表接收不到(dao)光(guang)(guang)(guang)(guang)信號時，顯示-70dBm，說明光(guang)(guang)(guang)(guang)纖不通，需要檢查(cha)光(guang)(guang)(guang)(guang)纖跳線、光(guang)(guang)(guang)(guang)纜是(shi)否斷開或損壞。