TVI Cameras - HD over Analog Cables
TVI cameras send compressed digital signal over analog cable.
TVI allows customers who already have run BNC cable (the cable used by old CCTV systems), the ability to upgrade to an HD solution without changing any wiring. One of the best things about TVI is that you can upgrade cameras gradually. TVI recorders (TVI DVRS) are Backward Compatible with Analog Cameras - if you plug an analog camera into a TVI recorder it will recognize that it is receiving analog rather than TVI's digital signal and record in analog; if you plug a TVI Camera in it will recognize the digital signal and record in HD. Because the video is compressed, TVI is perfect for upgrading to HD if you have already run BNC cable, but will not replace IP cameras as the dominant cameras of the future.
TVI recorders can accept signal from TVI cameras (SCW, Samsung, TVT, and Hikvision make TVI cameras) or Analog cameras. TVI is a transitional technology to help people with already existing cable get higher resolutions. All new installations should use IP cameras and NVRs as IP can already do 5x the resolution as TVI and IP cameras are significantly easier to install.
Unlike IP cameras, TVI cameras need Power Adapters (Wall Plugs) or Power Supplies (Power Distribution Boxes). Power distribution boxes are highly recommended, as power adapters don't have any surge protection. TVI cameras use Siamese Cable and BNC Connectors.
You may need a Splitters or Converter, depending on your application.