Audio Systems: transferring dos commnds, aes ebu, analog signal

Question
how to transfer a command from a to d commands?

Answer
I need more information about what you want to do.

In audio equipment the a to d conversion is done by a converter - which is usually a self contained IC chip or some kind.

Here is a little tutorial on a to d conversion that may be of interest to you:

http://www.facstaff.bucknell.edu/mastascu/eLessonsHTML/Interfaces/ConvAD.html

And, here is a multi-channel a to d converter that complies with the AES/EBU standards - which allow for use in recording and mastering digital recordings for later applying to a compact disc or other digital audio media.  Since you are coming in on the audio systems questionaire I am assuming you are interested in audio applications.

Here is an Analog Devices adc that is popular among manufactuers:

http://www.analog.com/en/prod/0,2877,760%255F789%255FAD1870,00.html

Here is some design data for an adc:
http://www.intel.com/design/mcs96/technote/2380.htm

This will give you and idea of the design procedure for using a device in a system.

The fundemental procedure for conversion is to sample the analog signal at some high frequency rate, then assign digital numeric codes to each discrete voltage level.  The number of bits used in the sampling sequence will determine the number of levels.  In audio it is common to use 16 bit resolution or greater.  For 16 bits, or 2 to the 16th power will provide for the input wave to be broken down into 65,000 levels from the highest to the lowest magnitude of the analog wave.

If I have missed the mark on what you were asking about, please come back to me for another session.

CLeggsan