Storing and Regenerating waveform from file

[Sarang Jaiswal]

Hey all,

I want to store the waveform coming from the function generator in a file and then regenerate it back and display it in the graph.

I am using "Write waveform in file" and "Read waveform from file" vi's which are there in functions -> waveform -> waveform IO.

I am directly giving the output of the DAQmx Read to the input to the "write waveform in file" and then while retreiving back i am directly giving the output data to the Graph.

i am saving data for 5 seconds, but only 0.04 sec data is retrived back in graph. if i save for 10 sec then also same thing is happening.

could any one please throw some light on it.

thank  you

[Dennis_Knutson]

When you are doing the save, how do you have the append to file input set? When you are acquiring 5 seconds worth of data, is this with a single acquisition or are doing it in a loop with a file save every iteration? If you're doing it in a loop, make sure the append to file is set to true.

[Chris_Cilino]

Sarang Jaiswal

I think the quickest way to solve your problem will be to use the "Write to Measurement File" express vi and "Read from Measurement File" (I'm assuming you're using LabVIEW 8.0). I'm not sure why the vis you're using aren't working out, but I believe the two I just mentioned will solve your problem quickly. They are located in Functions>>Programming>>File IO.

Best Regards,

Chris C

Applications Engineering

National Instruments

[Sarang Jaiswal]

Hey Chris_C and Dennis Knutson,

Well I am afraid I am not using LabVIEW 8.0 (I am using LabVIEW 7.1). But thanks for the suggestion. I have found the solution. Its there in the Examples Section. I have used these two examples.

1. Cont Acq&Graph voltage - To File (Binary).vi

2. Graph acquired Binary Data.vi

Thank you.