An intercom system has two main parts: the door station where visitors press the button, and the inside station where staff answer.
Door Stations Outdoor-rated enclosures with call button, speaker, microphone, and (for video intercoms) a camera. Mounted on the wall next to the door or integrated into a post for gate installations. Video door stations use wide-angle lenses to capture the visitor and the area around the door for better verification.
Master Stations and Desk Units The inside endpoint where the call is answered. Can be a wall-mounted master station, a desktop unit with touchscreen, a desk phone that answers intercom calls, or a mobile app on a smartphone. Multi-tenant systems route calls to individual tenant phones instead of a single master station.
Unlock Mechanisms Intercoms connect to electric strikes, mag locks, or gate operators to unlock the door remotely. The unlock signal comes from the master station, desk unit, or mobile app. This is where intercom and access control integration happens: instead of two separate unlock buttons, one system triggers both.
Power and Connectivity IP intercoms use PoE (Power over Ethernet) through standard data cabling, which simplifies installation. Analog intercoms use dedicated two-wire or multi-conductor cable. Wireless intercoms use battery, solar, or local AC power with WiFi or cellular connectivity.