HD-CVI stands for High Definition Composite Video Interface. CVI is an analog closed-circuit television video surveillance standard of high definition up to 4K video which allows the camera to send an HD signal over a standard coax or RCA cable. CVI not compatible with other similar analog video signals such as TVI, AHD, CVBS. Make sure that you’re not using more than 300 feet on the coax cable, and 1000 feet on the UTP with Video Balun. As the inventor of HDCVI technology, Dahua continuously invests in the technology to rejuvenate existing coaxial-based systems since its launch in 2012 with its own patents.