Door Station/Video Parameters Camera 1/4″ CMOS Resolution 720 × 576 Video Frame Rate PAL: 25 fps Door Station/Audio Parameters Audio Input Built-in Omnidirectional Microphone Audio Output Built-in Loudspeaker Audio Quality Noise Suppression and Echo Cancellation Door Station/Device Interfaces Four-Wire Interface 1 Four-Wire Interface (1-ch Video Input, 1-ch Audio Input/Output, 1-ch Power Supply, 1-ch Grounding)