U3 Latency Issue

Hi All,

I am using Labjack U3 to run a strobe light via Matlab (2013b) with a string of 1s and 0s to signal the on/off of the light.

The issue I am having is when trying to flicker at frequencies above 25Hz, there is no resulting signal to the strobe, when I run the strobe close to its max frequency around 22Hz I can see that it does not fully complete each on/off cycle suggesting a timing issue

Ideally I am looking at running the strobe at 40Hz so would need a latency of 12.5ms

I am using a windows XP (I know technical reasons as to why), but have tried the code on a Windows 7 machine and have the same result

From what I have read this kind of latency should not be a problem for Labjack

Anyone have any ideas what is going on?

Thanks

David

 

This is the code I am using to interface with labjack

 

 

for second = 1:time

 

        tstart = tic;

    

        ljudObj.AddRequest(ljhandle, LabJack.LabJackUD.IO.PUT_DAC, 0, volts, 0, 0);

        ljudObj.GoOne(ljhandle); %Send the request

        telapsed = toc(tstart);

        count = count + 1;

 

        delay(halfphase-telapsed);

        telapsed = toc(tstart);

       

 

         tstart = tic;

         ljudObj.AddRequest(ljhandle, LabJack.LabJackUD.IO.PUT_DAC, 0, 0.00, 0, 0);

         ljudObj.GoOne(ljhandle); %Send the request

         telapsed = toc(tstart);

         delay(halfphase-telapsed);

     

     

end