EST3 Installation and Service Manual

System overview

Audio subsystem description

The audio subsystem consists of a variety of signal sources, integral amplifiers, and sophisticated control software. The

3-ASU Audio Source Unit is available with the optional 3-FTCU

Firefighter Telephone Control Unit as the model 3-ASU/FT. The

ASU/FT is the only audio equipment required at the fire command control center. Zoned audio amplifiers are distributed throughout the system and provide the de-multiplexing, switching, amplification and circuit supervision.

Network audio riser wiring

A digital network audio riser consisting of a single pair (Class B) or two pairs (Class A) of wires connect all amplifiers together.

Since the digital signals are multiplexed, any of 8 independent audio sources can be directed to any amplifier connected to the network. All command and control signals for the audio system are distributed over the network data riser.

CPU

TB2

AUDIO

A IN

AUDIO

A OUT

AUDIO

B IN

AUDIO

B OUT

CPU

TB2

AUDIO

A IN

AUDIO

A OUT

AUDIO

B IN

AUDIO

B OUT

CPU

TB2

AUDIO

A IN

AUDIO

A OUT

AUDIO

B IN

AUDIO

B OUT

CPU

TB2

AUDIO

A IN

AUDIO

A OUT

AUDIO

B IN

AUDIO

B OUT

From

AUDIO DATA PRIMARY on 3-ASU

Figure 1-2: Class B network audio riser wiring

1.6 EST3 Installation and Service Manual