Multisim and Labview 2019

[CmcOlivares]

Hello. Thanks for you atention. I am living in Portugal, i am a student of a engineering cours in Lisbon University.

I will describe my problem, or my doubt. If you help me i will be grateful.

I created a simulation in Multisim. A stable square wave oscillator, with a opamp and a condenser and Resistance, more or less.

In multisim simulation, it works good. I have a good square wave in osciloscope.

iIn Labview 2019, through the Simulation -> External Models -> Multisim -> multisimDesign tool, i have imported this design do block diagram of labview.

I placed it inside a simulation cycle.

The problem is that I can't get the frequency of the square wave generated in the multisim, through the Tone tool.

I can only visualize it in the waveform Graph.

My question is how can I get a numerical indicator that tells me what is the frequency of the signal generated in the multisim simulation?

I already understand that the multisim sends only one signal to Labview, the amplitude.

How can i use Tone or another tool to know the frequency of the sinal from multisim Design ?

The Tone frequency must be the same or near of teoric frequency....

Thanks

[CmcOlivares]

Nobody helps... ? 😕

[NPowl]

Heya,

If you take the output of your frequency, you can build a waveform and then use the various waveform functions e.g. Extract Single Tone Information. You can see more here in a previous post.

Cheers,

Nick

[CmcOlivares]

Thanks.

My problem is that -  multisim sends only the amplitude value to Labview. Dont send time's vetor, you know.

Labview cannot plot the signal, because it faults teime's vector.

. I can't get a square wave from the multisim simulation.

Using an extract tone, it can't get the frequency of the signal coming from the multisim.

Thank you for your kindness.

[NPowl]

Heya,

I'm not a Multisim guy so I'm not sure what Multisim outputs in this scenario. Are you able to export the time characteristics at all, or just give a constant dt if the waveform has this?

Regarding the loop in the image below - it looks like you're overwriting your Y value in every loop iteration. If you want a live frequency analysis, you'll want to keep your previous Y value but add the new value to the array: 

Otherwise, if you want to analyse at the end, build your array at the end of the loop:

Cheers,

Nick

[CmcOlivares]

Good afternoon.

Thank you for your kindness.

I am using a "Control & Simulation Loop", because I call the simulation of a module "Multisim", and in a normal loop this is not possible.

My problem is the Extract Tone doesnt read the real frequency. I tried to change the dt values ​​from 1E-7 to 10, and the problem remains. With dt = 1E-6, for example, it reads around 480 KHz. The realy value is around 1.3 KHz to 12 KHz. ( Varying the value in the selector, which gives 1 pf / Volt).

Please, i send you here the files Multisim and Labview. Would you to try it, please ?

I dont know what more to do...

Ty

hanks

Best regards.

[CmcOlivares]

Thanks to everyone who tried to help.

I think I found a solution for my project.

Thank you all !!

I leave my solution less here, because we can all learn and teach !!

I hope i can help you all.

🙂

[GerdW]

Hi Cmc,

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@CmcOlivares wrote:

I leave my solution less here, because we can all learn and teach !!

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Please replace ALL local variables inside this loop by wires!

(Even in a Simulation loop the basic DATAFLOW rules apply!)