How do I replace the step command for running an object in MATLAB2018a

In the following code;

DataRecorder = dspdemo.DAQRecorder(...
    'DeviceName', deviceName,...
    'SamplesPerFrame', samplesPerFrame,...
    'SampleRate', sampleRate,...
    'ChannelNumbers', 0,...
    'OutputNumOverrunSamples', true);

%%Acquire data continuously
% Acquire data through a simple while loop, until the time reaches the
% value previously defined in endTime.
% To terminate the acquisition manually press CTRL+C 

tstart = tic;
while (toc(tstart) < endTime)
    % Use step method to acquire SamplesPerFrame at a time from the device
    [data, numov] = step(DataRecorder);

      if(~isempty(data))
          plot(data), set(gca,'Xlim',[0, length(data)-1])
          drawnow
      end

      if(numov > 0)
          fprintf('Samples overrun: %g\n',numov)
      end
  end

In the above code the specific command;

[data, numov] = step(DataRecorder);

does not work in Matlab 2018a

How can I run that object in the same manner using Matlab2018a

I don't understand how objects work!

Thank you

[Walter Roberson]

What happens instead of step() working?

Answer 1

[Branko Celler]

Are you saying, replace command [data, numov] = step(DataRecorder); with [data, numov] = step();

That generates an error Error in DaqBasicAnalogInExample (line 61) [data, numov] = step();

and runs a demo of the step function!

[Walter Roberson]

No. You told us that that specific command does not work in MATLAB R2018a, but you did not tell us how you know that it does not work. Does it produce an error message? Does it accept the command but nothing happens?

Answer 2

[Branko Celler]

The code comes from the following:

https://au.mathworks.com/matlabcentral/fileexchange/46685-live-data-acquisition-for-real-time-signal-processing-in-matlab

When I run the program at a much slower sampling rate (500samples/sec), the program runs and ultimately shows a plot after it completes, but generates the following warning;

>> DaqBasicAnalogInExample
Warning: DesiredTerminalConfiguration specified not supported 
> In dspdemo.private.DeviceManager/constructSessionDevice
  In dspdemo.private.DeviceManager/constructDevice
  In dspdemo.DAQRecorder/setupImpl
  In DaqBasicAnalogInExample (line 60) 
line 60 is the command;
[data, numov] = step(DataRecorder);

I hope that this is a little clearer!

Regards

Branko

[Walter Roberson]

Unfortunately that involves a toolbox that is not available for my Mac, so I cannot look at the code at the moment.

Answer 3

[Branko Celler]

Thank you for your efforts. However for some strange reason it is now working. I still get the warnings, but I am collecting and displaying data It may have had something to do with my setting up of the NI device