I am using 2011b 32bit, I have a main body of code and want to use the DAQ-TB to call an NI-USB based DAQ to generate signals. I want to call the DAQ function from my main program, execute it to generate a signal continuously, and return to the main function to conduct other analysis and also use the DAQ to make measurements. I want to return and change the DAQ output depending on the measurements made and other data related to the DAQ output. I also have to access other hardware. The waveform generator works fine and runs continuously while I am in that script, but when I call it from an external script it shuts down. This is the script I want to call from the main body:
s = daq.createSession('ni');
s.addAnalogOutputChannel('Dev1', 0, 'Voltage');
s.Rate = 2e6; %in Hz
Dur = .5; % In seconds, but system polls for more data, so it doesn't matter?
Fr = 5e3; % In Hz
signalVoltPk = 2; % In peak voltage
squareWv = 0; % Set to 1 for square wave.
Npts = round(Dur*s.Rate);
x = (0:(Npts-1))/s.Rate;
data = signalVoltPk*sin(Fr*2*pi*x); data=data(:);
if squareWv == 1; data(data < 0) = - signalVoltPk; % Convert sin wave to square wave data(data > 0) = signalVoltPk; end
lh = s.addlistener('DataRequired', @(src, event)src.queueOutputData(data));
s.IsContinuous = true;
When I look through the DAQ function generator included with the toolbox, all the calls are to internal functions.... Is that necessary?