Technical data

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

The signal object would be tied to a Feeder object, “Buffer”, which would direct the sound to one

of the analog outputs. The sound would then be played on the speciﬁed analog output (or outputs).

To add an object to the model, go to either Signal, Controls, or Feeders from the menu shown

above. You will come to a list of the objects in the current model. If you have just started, the list

will be empty. Press “Insert” to get a list of the objects you can insert. Move the cursor to one of

the objects, and press ENTER. This will put one of the objects on the screen.

The objects and the object screens are described in great detail in the Model Builder Reference

manual. There are some common details.

Parts that appear in blue type can be changed by the user. Things in yellow cannot, as they denote

results. A series of dashes indicates where another object can be tied in. To tie in another object,

go to the dashed line and press ENTER. This will give you the list of objects you can tie in. To

select an object, move the cursor onto it and press the T

AB key. (Not the ENTER key!)

To see an example of a basic model, exit out of Model Builder to DOS and type DRED_LOC.

This will load the daily readiness test model, described in chapter 5.

Audio Processing (DSP) Hardware

As mentioned previously, models run on the CPU, but they control the sound processing of the

DSP, with one model running simultaneously for each DSP.

The two types of DSPs are Waveform Synthesizers and TDM Controllers. They process sound in

exactly the same way. The difference between them is how they get sound onto and off of the

card.

The Waveform synthesizer has 8 analog inputs, with analog ampliﬁers and A/D converters. It also

has 8 analog outputs which are driven by D/A converters.

The TDM controller also has no analog inputs or outputs. Instead, it sends and receives audio sig-

nals in digital form over a digital serial link called a TDM (for Time Division Multiplexed) link.

This link attaches to one or more RIUs (Remote Interface Units). The RIUs pick up the digital

sound and convert it to analog. It also takes in analog sound, converts it to digital, and sends it

back on the TDM link back to the TDM controller. The TDM continues to do all the DSP func-

tions of the other cards. For a diagram of this, see Chapter 2, “Hardware Overview”, in the sec-

tions about RIUs and TDM controllers.

Control Signal Feeder

In_Int Play

Sound

Buffer

D/A Conversion,

audio output