Technical data

www.asti-usa.com ASTi DACS: Operation & Maintenance Manual (Version 4, Rev. B.1)

Chapter 2: System Description

This chapter describes the different Digital Audio Communication System (DACS) hardware

components and typical system conﬁgurations.

Digital Audio Communication System Description Overview

The ASTi Digital Audio Communication System (DACS) is a fully integrated DSP based system

designed to provide a total solution to all aspects of the sound simulation environment including

aural cueing, intercom, navigational beacon and radio communication simulation, inter-trainer

networked radio and intercom, Distributed Interactive Simulation (DIS) compatible communica-

tions, caution/warning tones, RWR and ECM equipment audio, as well other audio simulation

components.

Included with the DACS is the ASTi Model Builder sound model generation software which

allows the user to build, test, and modify aural cue and communications sound models quickly

and easily without resorting to any DSP or high level software language programming.

When constructing sound models, the user selects the sound objects required for the speciﬁc

sound simulation from the Model Builder menus and inserts them into the sound model. Sound

Objects include various types of sound, mixing and control objects such as engines, radios, mix-

ers, communication panels, waveforms, input controls, functions, balancers, etc. The user can

connect these objects, set parameters locally, or connect parameters to host input controls. Sound

models can then be tested, tuned, and modiﬁed in real time.

Depending on conﬁguration, the DACS is capable of simultaneously running several user deﬁned

audio simulation models at one time. Each model consists of groups of user selected sound

sources, mixers, and controls which generate the desired audio simulation. Models may also be

connected, allowing growth and expansion of model complexity and capability.

For large applications such as those involving multiple networked training devices or large num-

bers of operators, multiple DACS units may be employed to achieve an overall networked com-

munications simulation solution.

There are two main processing components in the Digital Audio Communication System hard-

ware platform, the main CPU or Model Processor and the Audio Processor(s). Audio processor

components consist of Waveform Synthesizers and TDM (Time Division Multiplex) Controllers.

A DACS may have multiple audio processor components.

The Model Processor runs the Model Builder sound model run time and development environ-

ment and much of the higher level sound model control. This includes such functions as reading

input data from the host, calculating and updating mixing gains, frequencies and control values

for each sound, mixing, or control object in the sound model(s), generating navigation identiﬁer

keying, calculating radio parameters and signal effects, etc.

Waveform Synthesizers incorporate a Digital Signal Processor (DSP), and depending on the syn-

thesizer conﬁguration, up to eight analog input and eight analog output channels. Analog audio

channels are connected directly to the card local to the DACS. The Waveform Synthesizer DSP

runs the signal processing algorithms associated with each sound model, such as waveform gener-

ation, sound ﬁle sample and playback, voice mixing, etc.