How do I specify which channel I want to use to output data in the Data Acquisition Toolbox?

Hi,

I want to output two different data sets at different times from my computer's sound card. I know how to add two channels to my output, but when I'm sending the data, how do I specify to Matlab which channel I want to use? I want to get data from y1 to go through ch1 and data from y2 to go through ch2.

My current code:

ao=analogoutput('winsound');

addchannel(ao,1);

addchannel(ao,2);

zero=zeros(15001,1);

Fs=8000;

t=0:1/Fs:.25;

y1=sin(2*pi*440*t)';

y2=sin(2*pi*600*t)';

putdata(ao,[y1 zero])

start(ao)

wait(ao,3)

stop(ao)

putdata(ao, [zero y2])

start(ao)

wait(ao,3)

stop(ao)

delete(ao)

clear ao

Thanks!

Answer 1

[Sean de Wolski]

It's been awhile size I've done this but doesn't each column of the data go to the respective channel as it was created. Consider the doc putdata example with a few small modifications:

ao = analogoutput('nidaq','Dev1');
ch = addchannel(ao,0:1);
set(ao,'SampleRate',1000)
data1 = linspace(0,1,10000)';
data2 = rand(size(data1));
putdata(ao,[data1 data2])
start(ao)

Here data2 will go to the second channel (1) and data 1 will go the first (0) from when these were added with addchannel. Swapping the inputs would reverse this.