Trouble with diplaying the sine wave

[krithika]

Hi

For my application i need to generate continuous sine wave and be able to control the amplitude/frequency etc. I also want to diplay the same using either waveform chart or graph.

Refering to the generating continuous Sine wave and basic analog output VI examples i have the following VI. But i am not able to see the sine wave being read.

I am really new to LABVIEW AND NEED ALL THE HELP I CAN GET!!

Pls help.

Thanks

Krithika

[mfitzsimons]

The VI you posted is not a valid VI

[krithika]

Can you pls help me sort it out!!??

Thanks

[tbob]

I cannot open your attached vi.  I get an error message saying that it is not a vi.  Try posting your vi again.  When generating sine waves, you must pay attention to the sample rate and number of samples vs frequency.  The sample rate should be at least twice the frequency, but it is much better to have the sample rate about 10 times the frequency.  If the number of samples is too high, the display will be all bunched together making the sine wave impossible to see.  If the number of samples is too low, you will not see a complete sine wave.  See attached vi.

[krithika]

I have re-attached my VI . Hope you are able to open this one.

My Version of LABVIEW is 7.0.

Thanks

Krithika

[Dennis_Knutson]

You're missing a basic understanding of how LabVIEW works. You have the sine wave generation in a while loop. A while loop does not pass anything out until it finishes. With the data dependency you have between the output of the while loop and the first AO Write, the AO write and the lower while while will not start until the top while loop finishes. I would recomend you use DAQmx and look at the shipping example called Cont Gen Voltage Wfm-Int Clk-Non Regeneration if you want to change the waveform on the fly. There's also a shipping example called Function Generator that uses the old traditional DAQ functions.

[krithika]

Thanks!

Can you tell me how to combine the analog output function and function generator VI.

Thanks

Krithika

[Dennis_Knutson]

I thought I just did. Cont Gen Voltage Wfm-Int Clk-Non Regeneration uses the Basic Function Generator to create a waveform and this is passed to DAQmx Write. Move the Frequency and Amplitude controls inside the while loop and try it.

[krithika]

Hi Dennis

Thanks! Sorry ........ but i can use only examples for traditional DAQ.

I have attached two seperate VI's

Sine: that will generate Sine wave

Analog output: to that generate the analog output .

Can you pls tell me how to put them together.

I looked at the example : Function Generator. I placed a diplay(waveform) - at the signal output (the same place where its fed to the analog write).

I am really new to LABVIEW and i think these questions might be silly. But i need all the help.

Thanks

Krithika

[Dennis_Knutson]

But according to your post here, the board you have is supported by DAQmx.