最新资讯NEWS
 您现在的位置:澳门网站网址 > 资讯资讯 > 最新资讯 > 正文
【安防百科】选购视频监控线缆的注意事项
编辑:澳门官方网站平台  更新时间:2017-04-19 10:42:05
视频信号传输通常选用直接调制技能、以基带频率(约8MHz带宽)的方法,最常用的传输介质是同轴电缆。同轴电缆是专门规划用来传输视频信号的,其频率丢失、图画失真、图画衰减的幅度都比较小,能极好的完结传送视频信号的任务。通常选用专用的SYV75欧姆系列同轴电缆,常用型号为SYV75-5(它对视频信号的无中继传输间隔通常为300-500m);间隔较远时,需选用SYV75-7、SYV75-9乃至SYV75-12的同轴电缆(在实践工程中,粗缆的无中继传输间隔可达1km以上);也有经过增加视频扩大器以增强视频的亮度、色度和同步信号,但线路中搅扰信号也会被扩大,所以回路中不能串接太多视频扩大器,不然会呈现饱满现像,致使图画的失真;间隔更远的选用光纤传输方法,光纤传输具有衰减小、频带宽、不受电磁波搅扰、重量轻、保密性好等一系列长处,首要用于国家及省市级的骨干通讯网络、有线电视网络及高速宽带计算机网络。而在闭路电视监控体系中,光纤传输也已成为长间隔视音频及操控信号传输的首选方法。
Video signal transmission is usually the use of direct modulation skills to baseband frequency (about 8MHz bandwidth) method, the most common transmission medium is coaxial cable. Coaxial cable is specially designed for the transmission of video signals, the frequency of loss, picture distortion, picture attenuation amplitude is relatively small, can be an excellent end of the task of transmitting video signals. Usually choose special SYV75 OHM Series coaxial cable, commonly used type SYV75-5 (for video signal transmission without repeater spacing is usually 300-500m); distance, coaxial cable, and the need to use SYV75-7 SYV75-9 SYV75-12 (in practice, thick cable no relay transmission distance can reach more than 1km); or after adding video amplifier to enhance video brightness, chroma and synchronous signal, but the signal line in trouble will be magnified, so the loop cannot connect too many video amplifiers, otherwise will show the full picture of the phenomenon, resulting in distortion; selection of optical fiber transmission interval further, the optical fiber transmission with small attenuation the band width is not affected by electromagnetic interference, light weight, good security and a series of advantages, mainly for national and provincial and municipal backbone communication network, cable TV network and high-speed broadband Computer network. In the closed circuit TV monitoring system, optical fiber transmission has become the preferred method of long distance video and audio signal manipulation.
视频信号也可以用双绞线传输,这要用到双绞线传输设备。在某些特殊运用场合,双绞线传输设备是必不可少的。如:当建筑物内现已按归纳布线规范敷设了很多的双绞线(规范中称三类线或五类线)并且在各有关房间内留有相应的信息接口(RJ45或RJ11),则新增闭路电视监控设备时就不需再布线,视音频信号及操控信号都可经过双绞线来传输,其间视频信号的传输就要用到双绞线传输设备。另外对现已敷设了双绞线(或两芯护套线)而需将前端摄像机的图画传到中控室设备的运用场合,也需用到双绞线传输设备。双绞线视频传输设备的功用就是在前端将合适非平衡传输(即合适75Ω同轴电缆传输)的视频信号转换为合适平衡传输(即合适双绞线传输)的视频信号;在接纳端则进行与前端相反的处理,将经过双绞线传来的视频信号从头转换为非平衡的视频信号。双绞线传输设备自身具有视频扩大效果,因而也合适长间隔的信号传输。对以上不一样的传输方法,所运用的传输部件及传输线路都有较大的不一样。
Video signals can also be twisted pair transmission, which uses twisted pair transmission equipment. In some special occasions, twisted pair transmission equipment is essential. When the building has been summarized by laying the twisted pair wiring specification lot (specification called three lines or five lines) and in each room is reserved in the corresponding information interface (RJ45 or RJ11), the new CCTV equipment do not need to wiring, video and audio signal and control the signal can be transmitted through the twisted pair transmission, the video signal will be used twisted pair transmission equipment. In addition to the laying of twisted pair (or two core sheath line) and the need for the front camera pictures to the central control room equipment, also need to use twisted pair transmission equipment. Twisted pair video transmission equipment function is in front of the right (i.e. the appropriate unbalanced transmission 75 coaxial cable transmission) conversion of video signals to the appropriate balance of transmission (i.e. the right twisted pair transmission) of the video signal is processed; and the front opposite in the receiving end, the video signal from the twisted pair came convert video signal unbalanced. The twisted pair transmission device has a video amplification effect, and is suitable for long distance signal transmission. For the above different transmission methods, the use of transmission components and transmission lines are not the same.
通讯线缆通常用在装备有电动云台、电动镜头的摄像设备,在运用时需在现场装置遥控解码器。现场解码器与操控中心的视频矩阵切换主机之间的通讯传输线缆,通常选用2芯屏蔽通讯电缆(RVVP)或3类双绞线UTP,每芯截面积为0.3mm2~0.5mm2。选择通讯电缆的基本原则是间隔越长,线径越大。例如:RS-485通讯规则的基本通讯间隔是1200m,但在实践工程中选用RVV2-1.5的护套线可以将通讯长度扩展到2000m以上。当通讯间隔过长时,需运用RS-485通讯中继器。
Communication cable is usually used in the equipment equipped with electric PTZ, electric lens camera equipment, when used in the field of remote control device decoder. The scene decoder and the control center of the video matrix switch between the host communication transmission cable, usually choose 2 core shielded communication cable (RVVP) or the 3 kind of twisted pair UTP, each core cross-sectional area of 0.3mm2 ~ 0.5mm2. The basic principle of selecting communication cables is that the longer the distance, the larger the wire diameter. For example: RS-485 communication rules of the basic communication interval is 1200m, but in the practice of Engineering in the use of the RVV2-1.5 cable can be extended to the length of more than 2000m. When the communication interval is too long, the need to use RS-485 communication repeater.
操控电缆通常指的是用于操控云台及电动可变镜头的多芯电缆,它一端衔接于操控器或解码器的云台、电动镜头操控接线端,另一端则直接接到云台、电动镜头的相应端子上。因为操控电缆供给的是直流或沟通电压,并且通常间隔很短(有时还不到1m),基本上不存在搅扰疑问,因而不需要运用屏蔽线。常用的操控电缆大多选用6芯或10芯电缆,如RVV6-0.2、RVV10-0.12等。其间6芯电缆别离接于云台的上、下、左、右、自动、公共6个接线端,10芯电缆除了接云台的6个接线端外还包含电动镜头的变倍、聚焦、光圈、公共4个端子。在闭路电视监控体系中,从解码器到云台及镜头之间的操控电缆因为间隔比较短通常不作格外请求;而由中控室的操控器到云台及电动镜头的间隔少则几十米,多则几百米,对操控电缆就需要有必定的请求,即线径要粗,如选用RVV10-0.5、RVV10-0.75等。
Control cable usually refers to multi core cable and electric control PTZ zoom lens, it is connected with the PTZ controller or decoder control terminal electric lens, the other end is directly connected to the corresponding terminals, electric lens on the head. Since the control cable is supplied with a direct current or a communication voltage, and is usually very short (sometimes less than 1m), there is no interference, and the shielding line is not required. Most of the commonly used control cable 6 core or 10 core cable, such as RVV6-0.2, RVV10-0.12, etc.. The 6 core cable were connected to the head of the upper and lower, left and right, automatic, public 6 terminals, 4 zoom, focus and aperture, the common terminal 10 core cable with 6 terminal connected platform also includes electric lens. In the closed-circuit television monitoring system, from the decoder to Yuntai and lens control cable because of the relatively short intervals generally do not make special requests; and from the control room controller to PTZ and lens intervals ranging from tens of meters to several hundred meters, to control the cable would need to have certain requirements, namely line size to rough, such as the selection of RVV10-0.5, RVV10-0.75 etc..
声响监听线缆通常选用4芯屏蔽通讯电缆(RVVP)或3类双绞线UTP,每芯截面积为0.5mm2。在没有搅扰的环境下,也可选为非屏蔽双绞线,如在归纳布线中常用的5类双绞线(4对8芯);因为监控体系中监听头的音频信号传到中控室是选用的点对点布线方法,用高压小电流传输,因而选用非屏蔽的2芯电缆即可,如RVV2-0.5等。
Sound monitoring cable is usually the use of 4 core shielded communication cable (RVVP) or class 3 twisted pair UTP, each core cross-sectional area of 0.5mm2. In the absence of disturbed environment, can also be selected as the unshielded twisted pair, such as commonly used in the induction wiring in 5 UTP (4 to 8 cores); because the audio signal monitor head monitoring system to control room is the selection of the point-to-point wiring method, with high voltage and low current transmission, so choose 2 core cable can be non shielding, such as RVV2-0.5 etc..



了解更多详情,请搜索:济南保安企业,山东保安企业,山东保安服务,济南保安服务 澳门网站网址/ 欢迎您的光临!
澳门网站网址是经山东省公安厅批准并于工商登记机构合法注册从事现代化安防业的综合服务企业,是目前济南市较早具有专业化、规范化、科学化、现代化的安防服务企业。企业的主要服务有门卫、巡逻、守护、区域秩序维护等保安服务....
澳门网站网址
TEL:0531-88958110
ADD:历山路72号
澳门网站网址
 
Copyright 2013 @ 澳门网站网址 鲁ICP备15005702号-1 流量统计 澳门网站网址是专业的济南保安企业,为您提供济南保安服务,山东保安服务.
技术支撑:驰翔科技 备案号:鲁ICP备15005702号-1
XML 地图 | Sitemap 地图