How does CCTV works?
A CCTV system is comprised of video cameras that capture and
send images to one or more monitors (or TV) or a video recording device through
what is called a CIRCUIT.
The CCTV CIRCUIT
There are two types of circuits for CCTV. The analog and
IP-based networks.
Analog CCTV
An analog circuit generally requires a dedicated wiring to
carry video signals generated by the cameras to a central computer and from
this central signal is derived monitors and video recording devices. It
requires a cable for each camera installed.
IP networks based CCTV
A circuit of this type is based on IP technology (in which
the same is based Internet). In this case, the cameras have within a
minicomputer with the ability to convert and encode the video into data that
can be sent over a computer network, whether a network already installed in the
business or home, or the same network Internet.
The advantages of this system is that it is cheaper still to
facilities already existing network can be used: the same wiring used (or you
can use wireless networks), and can be used one or more PCs to view and record
video images. It is clear that this will depend primarily on the number of
cameras and benefits are needed.
Another advantage of IP-based CCTV networks is that thanks
to the minicomputer that have cameras, you can set the system to react before
certain events or circumstances, for example: recording only when motion is
detected, send alerts by email, SMS or phone, record the situation, triggered
at certain times, etc.
Hybrid CCTV
In this case the analog and IP based systems coexist.
Usually this type of CCTV is used in the event that there is a prior
installation of CCTV analog type and wants to expand the system or the new
system based on IP networks without discarding the old system used. In this
case any additional equipment such as converters and / or adapters are used to
convert analog signals to digital.
Video surveillance cameras
There are a variety of cameras that can be incorporated into
a CCTV system. The choice of camera depends on the needs and objectives of each
case, and the environment where they will be installed. For that reason we
always do a preliminary analysis of the environment that you want to monitor to
design a reliable and efficient solution.
According to circuit technology, cameras can be:
Cameras Analog: for analog circuits.
IP cameras, for circuits based on IP networks. Quickly they
attach to any type of computer network.
The cameras are broadly classified as:
Indoor Camera: for environments protected from weather.
Cameras outside: these cameras are ready to operate in areas
exposed to moisture, extreme temperatures, etc.
Dome camera: these cameras have a call dome housing that
make hiding more discrete design and direction you are pointing. They can be
installed both indoors and outdoors, there are even more vandal resistant
housing with tamper-resistance and vandalism.
Plus:
Fixed cameras, these cameras have a fixed field of view once
installed. It is one of the most used types and is the ideal choice in
applications where it is useful that the camera is visible.
Mobile cameras PTZ (Pan-Tilt-Zoom): These cameras have the
ability to change their orientation with vertical / horizontal movement, zoom
and also according to the operator's instructions. The movement is controlled
through a much like a joystick that sends control signals to the camera device.
There are other options for special cases such as:
Cameras for night vision camera estipo can generate infrared
images from
Thermal cameras: these cameras produce images based on the
heat that radiates from any object, vehicle, animal or person. These cameras
can be installed in full darkness and deliver a video image for an operator to
suspicious activities at any time.
Video recording devices
The images generated by the cameras, whether they are
digital or analog, can be recorded to keep a log file or review the video at
another time if you want to verify or prove something.
In an analog system, it is necessary to have special
equipment to do this work. In the case of a CCTV based on IP networks (or
hybrid) , this equipment can be replaced by a computer running a software
program that takes pictures of the cameras and generates video files, saving
significant costs and usually You can use any available PC in the business or
home.
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