05-17-2012 04:19 AM
i am trying to transmit psk modulated signal from analog output channel to analog input channel of the daq card kusb 3116 with the help of bnc connector wire. i am able to modulate, D/A conversion and writing to the analog output channel i am able to get my sent signal too but the problem is shown in black circle in the attatched picture, LV Link vi at recieving part is getting 1D array of 64 bit real how ever for demodulating it i need complex waveform(cluster of 3 elements)having t0, dt and Y. plz help me with this, i have tried to use my daq card with VISA too. but i was only able to find very little help from tutorials and examples. sir, plz download these LV Link 3 vi too, so that my attatched vi works, and definitely it will ask for the open layer board too. plz help me as i am in my final semester of engineering and really stuck with this. thanx
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05-17-2012 03:50 PM
Judging from your png you need to continue using the build waveform primitive. Hover over it and drag it down so you have 3 entries. They will most likely say "Attributes". Right click on one>>Select item>>t0, repeat and select dt on the other one. Wire appropriatly. Don't know why you are building that upper cluster.
Always keep open the context help...Ctrl H...
05-21-2012 04:21 AM
sir i tried to do this in the way you told but got this problem as shown in the picture, plz help me with this
05-21-2012 01:33 PM
Ok now I can see why you were using the bundle by name. You were correct. Here is what I would try. First delete the broken wire from MT Demodulate PSK. Then right click the input complex waveform and create constant. Delete the wire from the constant to the input. Then wire the constant into the top input of a bundle by name function. Secondly lay down a type cast function. Wire your array of dbl data in. On the top input wire a array of complex double.(You can Ctrl drag it out of the other constant you made to create a copy.) Wire the output into the y input of the bundle by name and then into the MT Demodulate PSK.
Hope this works.
05-22-2012 02:15 AM - edited 05-22-2012 02:23 AM
05-22-2012 02:43 AM
05-22-2012 02:55 AM
sir one more thing i want to ask about this error message as shown in the attatched png. it pops up whenever i try to modulate, tx on analog output of daq card, rx on daq card and try to demodulate(this is still under process), my vi runs for some time and then this error pops up.
05-22-2012 10:06 AM
nauman,
Attached is how I would wire up the typecast. Note that there might be easier ways to do this but this is just the first one I thought of.
As to your hardware error I really can't address the problem as I don't have that same hardware. I speculate that you are getting an overrun error because you aren't reading fast enough or you are running out of buffer space but that is just a guess. One of your png shows a while loop that looks like it is running unthrottled. You might want to put a wait (ms) into that loop with a value of let's say 20. You also might want to consider a producer consumer architecture to divorce that data collection from the data processing.
Looks like we are on different sides of the world judging from our post times.
Hope this helps.
05-23-2012 01:48 AM
sir i have done this too but still getting no complex waveform for demodulating.
05-23-2012 04:05 AM
sir now i am getting this problem. actually i am transmitting from one vi to analog output (on daq card) and then on second vi to analog input (from daq card).