The Alpha Communications IA502 Multi- Entrance Controller allows intercoms systems using the IA543, PK543, PK543A, or PK205 amplifier the ability to have multiple entry panels with the security feature of automatically determining the calling panel, and engaging only voice communications and door release for that specific entrance. The quantity of IA502s needed for a multi-entrance system is determined by subtracting 1 from the total number of entries in the system (e.g., (3) entrances would require (2) IA502 units) up to a maximum for eight entrances.