Digital video telephone is used for video and audio communication with video outdoor panel or audio communication with audio outdoor panel. It also provides phone to phone intercommunication, release of electric door strike and door bell function. The system is able to operate up to 45 video telephones and 55 audio telephones. Each main - primary telephone has to be identified (programmed) with a system number which assigns the telephone to a precise push button or a code dialed on the outdoor panel. There can be other 3 additional – secondary video or audio telephones connected to the primary video telephone. They have the same logical address as the primary one – they are assigned to the same push button or code. This allows the installation of up to 4 telephones within one flat or office.

To power the video door entry system DDV KARAT a power supply PS-5E is used. This power supply provides power only for the video system (18 VDC). The electric door lock must have own source of power, as well as the additional camera that can be connected to the video telephone. The type of power supply for additional system components must be selected in order to meet their technical requirements and the manufacturer recommendations.