The Dahua's analog Eyeball camera HAC-HDW2802T-Z-A has a built-in microphone, varifocal motorized lens 3.7~11mm, and provides 8 megapixel video. HDCVI technology supports 4 signals to be transmitted over 1 coaxial cable simultaneously, i.e. video, audio, data and power. Dual-way data transmission allows the HDCVI camera to interact with the HCVR, such as sending control signal or triggering alarm. Moreover, HDCVI technology supports PoC for construction flexibility.