4. IPAS Architecture & Operating Modes

4.1 Core Components

A typical IPAS deployment includes:

IP Speakers (ceiling, wall, horn, pendant types).
IP Audio modules for driving existing analog speakers.
IP Audio server / controller (e.g. SPA-S1000 or a speaker configured as Controller Mode).
SIP microphones (e.g. SPA-M2000) for desk paging.

4.2 Controller & Speaker Mode

In Controller & Speaker Mode, one speaker or audio server acts as controller mode device, managing source files and speaker mode speakers.

Key characteristics:

One controller-mode speaker manages multiple sources (audio files, BGM, IP microphones) and events such as SIP paging.
Sources and zones are configured via Device Registration, Source Registration and Zone Registration screens.
Only one controller-mode speaker should exist per broadcast system to avoid conflicts.
Ideal for multi-zone sites, complex scheduling and BGM, and large installations with many speakers.

Figure 7 – IPAS Controller, Source, and Zone Architecture

4.3 Independent Mode

In Independent Mode, each speaker runs standalone without a controller. The speaker stores its own audio files and plays them on demand.

Common trigger methods include:

HTTP/S SUNAPI URLs (e.g. Type=Play / Type=Stop).
VMS event actions (e.g. WAVE HTTP(S) Request, SSM CGI).
Camera handover actions using HTTP.

Independent Mode does not provide for multiple zones or groups, or shared BGM scheduling. It is ideal for single-speaker installations or small sites that only need simple event-to-message behavior.

Figure 8 – Independent Mode Configuration

4.4 Choosing the Right Mode

General guidance when choosing between modes:

Table 1 – Independent vs Controller Mode features

Feature / Capability	Independent Mode	Controller Mode
Audio file stored locally in speaker	✔	✔ (managed by controller-mode speaker)
Single-speaker playback	✖	✔
BGM scheduling	✖	✔
Trigger from local contact input	✔	✔
Trigger via HTTP(S) / SUNAPI	✔	✔
Trigger from VMS platforms (WAVE, SSM, Milestone, Genetec)	✔	✔ (zone/routing support)
Remote monitoring	✖	✔
Speaker group	✖	✔
Centralised priority & routing rules	✖	✔

Note:

Independent Mode speakers support event-based playback and 2-way audio only.
Button-based and scheduled playback require a controller-mode speaker.

Table 2 – Choosing the Appropriate IPAS Operating Mode

Requirement	Recommended Mode
One speaker, simple event-based playback	Independent Mode
Multiple zones / group paging / BGM	Controller & Speaker Mode
Enterprise site with VMS integration and zone-based audio control	Controller & Speaker Mode
Temporary or lab/test setups	Independent Mode