Generate Continuous Analog Output Using NI Card

Hello,

I am trying to generate continuous analog output using an NI card (NI USB-6343). The frequency of the analog output will be updated based on an algorithm and other input data. However, I am struggling with a more basic step and for now, I would just like to generate a continuous voltage signal using data called from a function (queueMoreData.m). My code:

daq.reset

daq.HardwareInfo.getInstance('DisableReferenceClockSynchronization',true);  % This is to overcome a different issue

d = daq.getDevices;

s = daq.createSession('ni');

ch = addAnalogOutputChannel(s,'Dev1','ao0','Voltage');

lh = addlistener(s, 'DataRequired', @queueMoreData);

s.IsContinuous = true;

queueOutputData(s,linspace(-1, 1, 1000)');

startBackground(s);

Which calls the function queueMoreData.m

function queueMoreData(src,event)

queueOutputData(s, linspace(-1, 1, 1000)');

end

This is based on this tutorial: http://uk.mathworks.com/help/daq/generate-analog-output-signals.html#btxscoj-1

But I get the following error:

_Warning: Error occurred while executing callback: Undefined function or variable 's'.

Error in queueMoreData (line 3) queueOutputData(s,linspace(-1, 1, 1000)');

Error in daq.internal.BaseClass/notify (line 91) obj.notify@handle(varargin{:});_

Etc Etc Etc

Any help would be very much appreciated!

Answer 1

[Walter Roberson]

In your callback change the reference from s to src

[Eddy H]

Great thanks, I should have spotted that!

The mistake is also in the documentation, I'm not sure if anyone reading this has the power to update that.

[Walter Roberson]

If you go to the bottom right of the documentation page and click on the button to say that it did not help you then you can describe the mistake and the report will be sent to an appropriate person.