Frequently Asked Questions
What Is CCTV and what does it do?
Closed circuit television, or CCTV, is used in different situations all over the world, and there is a good chance that most people have appeared on a CCTV network, whether they intended to or not. Most retail business employ a CCTV system to keep track of each customer that enters a store, deterring theft and vandalism.
A CCTV network can only be accessed by display units directly connected to the network. A CCTV network uses coaxial cable, infrared beams or microwaves to broadcast the signal to the connected receivers. This differs from a standard open television network in that anyone tuned to the open network's frequency can access the images being broadcast. With CCTV, the access is restricted.
CCTV has many practical applications, and it is in use in facilities and homes all over the world. A company may employ a CCTV network as a form of security to monitor the company grounds, and a private residence can employ a CCTV network in the same way. CCTV networks can be used in hospitals to allow nurses to keep an eye on multiple patients at the same time, and they can also be used to monitor traffic at busy intersections.
The majority of the video cameras used in a CCTV network use cameras that have a charged coupled device (CCD) chip for capturing digital images. This device creates images using small charges of electricity that are emitted when light hits a pixel. Each CCD chip generates hundreds of thousands of pixels that make up the image.
Each CCTV network has a time-lapse recording device that captures the images and stores them for use at a later time. Many CCTV networks are beginning to implement digital archiving systems that store all of the images on a series of computer hard drives, but many existing CCTV networks use VHS tape as their method of recording. With CCTV time-lapse technology, it is possible to store 24 hours of surveillance on one tape.
Monitoring CCTV cameras can be done in different ways. In some cases, a CCTV is meant for entertainment purposes, such as the presentation of a boxing match on a pay-per-view network, so these CCTV images are professionally edited for presentation. Most CCTV networks use switchers, quads or multiplexers to keep track of what each camera is capturing. A switcher displays the image from a camera for a few seconds and then automatically switches to the next camera. A quad system feeds images from up to four cameras into one display. The images of each camera in a quad system are recorded separately, but the quality is diminished because they only occupy one-fourth of the screen. A multiplexor is a high-speed switching device that can display and record the images of up to 16 cameras in full-screen mode and quality.
What is HD-SDI Camera?
HD-SDI CCTV cameras also known as HD security cameras, are quickly gaining popularity as a high definition video surveillance solution. With the advent of HD-SDI technology for security cameras, users can now capture 1080p resolution video using the same RG59 or RG6 coaxial cable that is used by traditional CCTV cameras.
What is EXHD-SDI?
Long distance up to 1800’ over RG6 Cabling. EXHD-SDI stands for extended High-Definition Serial Digital Interface, It is the common term for a high-definition digital video transmission standard known as SMPTE 292M. EXHD-SDI allows you to connect 1080P (1920 x 1080, 2MP) , (4MP) and ( 8MP)CCTV Cameras to a DVR over standard Coax cable. To do this you will need both a HD-SDI camera and an HD-SDI DVR.
What are the Advantages of EXHD-SDI?
The advantage of this technology allows you to use your standard coax cable, Long distance up to 1800’ over RG6 Cabling or up to 1000’ RG59 on your old DVR system and upgrade to High Definition video surveillance system. Prior to this type of DVR system you would have to use IP cameras and run new CAT 5 cable in order to get HD video. In addition with IP cameras you need to configure the cameras, and router to see each other on the network. With HD-SDI you connect just like a standard analog camera;
EXHD-SDI CCTV cameras are capable of true HD 1080p resolution (1920 x 1080). This higher resolution is the same as a high definition television and movies that consumers are use to. The SDI technology behind EXHD-SDI CCTV cameras is the same as the video cameras that capture video footage for “high def” motion pictures.
Some traditional CCTV cameras can actually capture slightly larger images than D1, but are unable to take advantage because traditional CCTV DVRs are limited to 704 x 480 resolutions, which is why D1 is the accepted max resolution in the CCTV industry.
What's difference between CIF, D1 and 960H for DVR?
Record resolution and recording frame rate are the most important specification for any DVR. Both of them determined the quality of video.
For real-time recording, the frame rate is 30fps; it's fixed for every DVR. The highest recording speed for a 4 channel DVR is 120fps, 8 channels DVR is 240fps, 16 channels is 480fps, 24 channel DVR is 720fps, 32 channel DVR is 960fps. 48 channels DVR is 1440fps. 64 channels DVR is 1920fps.
Typically most of DVR provides recorded resolution as QCIF, CIF, 2CIF, and D1, 960H
QCIF: 176 X 120 Pixels
CIF: 352 X 240 Pixels
2CIF: 720 X 240 Pixels
4CIF: 704 X 480 Pixels
D1: 720 X 480 Pixels
960H: 976 x 582 Pixels
1080P HD-SDI DVR for HD-SDI CCTV Camera
720P and 1080P NVR for IP camera
CIF is the abbreviation of Common Intermediate Format. CIF=360x240pixels
CIF format with follow features:
1. The resolution is suitable for video home system (VHS), with resolution 360x240pixels
2. Adopted non-interlaced scan
3. Using NTSC, play video maximum frame rate at 30 000/1001≈29.97fps/second
4. PAL tv system, resolution reach up to 288 tv lines.
5. CIF format is an old standard for video surveillance system
What is D1?
In cctv system industry, everybody knows D1 is the resoltuion of recording, playback and display resolution. Actually it's not true. D1 is a digital tv system standard format, it is divided into the following categories:
D1: 480i format (525i): 720x480 (resolution 480tv lines, Interlaced), and NTSC tv system with same resolution, Line frequency 15.25kHz, the equivalent of what we call 4CIF (720 × 576).
D2: 480P format (525p), 720x480 (resolution 480tv, progressive scan), with more clear compared to the D1 interlaced, is e the equivalent of DVD resolution.
D3: 1080i format (1125i): 1920x1080 (resolution 1080 tv lines, interlaced scan), high definition video format, resolution 1920x1080i/60Hz, Line frequency 33.75kHz.
D4: 720P format (750p), 1280x720 (horizontal resolution 720 tv lines, progressive scan), a low resolution compared to D3, but with reason of progressive scan, many people feel D3 is more clear than D4, especially when display the characters, resolution 1280x720p/60Hz, line frequency 45kHz.
D5: 1080P format (1125P), 1920x1080 (horizontal resolution 1080tv lines, progressive scan), the highest standard resolution in tv system, resolution 1920x1080P/60Hz, line frequency 67.5KHz.
What is 960H?
960H products are firstly intruded by Techwell and Sony, among analog security camera adopts sony new generation 960H CCD image sensor. Now, many security manufacturers begin to launch 960H series products for security solution. The 960H high definith analog camera adopts 960H CCD plus Effio DSP, offering high resolution, low noise and true color video footatge.
With development of 960H security camera, 960H DVR is coming into market. Only using 960H security camera and 960H DVR can build up a high definition 960H video surveillance system. 960H DVR can recording the video at 700 tv lines. It's compatible with 700 tv lines 960H security cameras. The 960H DVR offer high definition quality video both in real-time recording, viewing, playback.
Additionally, 960H resolution is 960x582, it's one quarter of 1080P resolution. So the 960H system can switch to 1080P system smoothly. Last, 960H security camera is the analog camera, transmitting video without delay, image resolution without coding or decoding, so the video footage more clear.
What is Video Baluns?
CCTV video baluns, also known as UTP baluns, allow traditional coax cable to be replaced by category 5 and other forms of twisted pair wire in CCTV video camera & surveillance installations. Video baluns allow installers to use more cost effective structured cabling techniques to wire security cameras. By using video baluns, UTP wire such as cat-5 can be run over longer distances easier than coax cable and for less money. Active balun transceivers enable UTP wires for cameras to be run distances up to 5,000 feet.
What is the difference between active video balun and passive video balun?
Active video balun: need connect adapters, and the distance is longer. Passive video baluns: no need connect adapters and the distance is shorter than the active video balun.
What is P2P?
Peer to peer (P2P) is a network protocol for computer users, used for downloading torrents or P2P files. Rather than connecting to the Internet, P2P software allows surfers to connect with each other to search for and download content. Because of the unique structure of the network, it is very efficient for downloading large files. A quick comparison to standard downloading explains why.
The Internet connects users or surfers to website servers. By cruising the Internet a user establishes a one-on-one connection with each website visited. If the user wants content (files) from that website, the server that archives the website transfers the files requested. Since a website can have hundreds or even thousands of visitors at any give moment, file transfer can be slow or sluggish at times. Download speed can slow to a trickle.
On a P2P network, when a user wants a file, installed software locates any copies of the file within the network. It then allows the user to create multiple connections with several sources that have all or part of the requested file. As parts of the file are received, they are also uploaded to other users that are requesting that file. This protocol of matching several sources to a request makes for an efficient download scheme.
What is POE?
Power over Ethernet (POE) is a technology which enables to connect network devices through Ethernet cable. Therefore it is not necessary to use two individual lines/1x data, 1x power supply/ for assurance of data connectivity and supplying. One Ethernet line is sufficient. This technology is applicable for wide range of network products such as Access Points, Routers, IP cameras, modems, switches, embedded computers or other network products.
What is the advantage of POE?
Benefits of Power over Ethernet
Why is PoE so important to Ethernet networks? The benefits of PoE are numerous from both a network efficiency standpoint as well as a cost standpoint. Any sized organization can enjoy the benefits of integrating Power over Ethernet into their network designs.