Tracé automatique du diagramme de Bode / Automatic plan of the diagram of Bode

[RM1tkk]

Bonjour je dois réaliser un programme permettant d'obtenir automatiquement le tracé d'un diagramme de Bode et d'extraire les caracteristique d'un filtre passe-bas. On doit pouvoir modifier le programme afin qu'il permette d'étudier les filtres passe-haut et passe-bande 1er et 2e ordre, le type de filtre sera choisi par l'utilisateur. Voici ci joint mon début de programme qui permet de faire un balayage en fréquence
Merci de vôtre aide.

Hello, I have to realize a program which allow us to automatically obtain the Bode graph and extract the characteristic of a low-pass filter.
We can modify this program to examine high-pass filter and bandpass filter 1st and 2nd order, the type of filter will be choose by the user.

Here is my beginning of my program which allow us to make a sweeping frequency.

Thanks for your help

Sorry for my mistake in english

[Victor.F]

Hi,

Thanks to post on NI Forums.

If you want to post in French you can ask the French community here

Now, I think I would need more informations on your setup to help you a little bit. First lets recap what you're doing:

You want to characterise analog filters (2nd, 3rd order) and you have some hardware to do so, generators and digitizers.

-What are the hardware references ?

-What is your LabVIEW Version ?

Looking at your program, it appears that you do not have any synchronization between the two loops (generation and acquisition ones) and I think you might need it if you want to know the freqency response of the filter at a known frequency.

So, what you should do is the following:

1-Generate a known tone/frequency

2-Do the acquisition of the signal coming out from the filter

3-Handshake or notifiy the generation loop that the acquisition took place succesfuly

then re-iterate those steps to sweep over the frequency range.

The handshaking can be done using Notifiers in LabVIEW, to know how to use it you can walk through the Exemples

In LabVIEW : Help>>Exemple Finder then search for Notifiers.

Concerning the bode graph, you can use some Maths functions to 20log the signal and then plot it in a graph.

You can also modify the graph properties (right clic>>properties) to edit X/Y scales etc.

Hope that helps.