The Complete Handbook of Intercom Accessories

Chapter 1: Understanding Intercom Accessories

An intercom accessory is any component that connects to, extends, or modifies a host intercom system without being the central switchboard or the primary audio station itself. It is a broad category that includes door stations, call buttons, relays for door release, additional speakers, headsets, power supplies, and the interface modules that make an old analog system talk to a new IP network. To work with these devices competently, you need to understand three things: how they physically and electrically connect to the system, what they are actually designed to do, and which of their specifications matter when you are selecting one for a specific environment. That is the basis of this chapter.

The most common misconception is that an intercom is a single product. In reality, a typical installation is a network of components, each with a specific job. The master station is the central unit that initiates and manages calls. The substation, often a door station or room station, is the remote unit that communicates back. The accessories are everything that supports, extends, or automates that communication path. For example, consider a typical apartment building entrance. There is a metal door station with a push button and a speaker/microphone on the exterior wall. There is an audio module inside each apartment that buzzes when the button is pressed. And there is an electric strike on the door that the tenant can trigger to release the lock. The door station, the audio module,