Ramp signal generation using NI-9263 module (with selectable number of ramp)

[MABADIE63]

Bonjour tout le monde,

Je viens demander un peu d’aide. J’ai commencé LabVIEW cette semaine et j’essaie de générer une rampe que je renvoie ensuite sur un NI-DAQ 9263 (je lis la sortie avec un oscilloscope).

Mon objectif serait de pouvoir choisir combien de motifs de rampe j’envoie, de définir les valeurs de Vmin et Vmax, et à terme de pouvoir sélectionner si la rampe est uniquement positive, négative, ou alternée.

Le problème, c’est que même si j’arrive à générer correctement la rampe (le signal apparaît bien en sortie du bloc "waveform"), le DAQ lui ne sort rien — aucun signal n’est visible sur l’oscilloscope.

Est-ce que quelqu’un aurait des idées ou des pistes à me proposer ?

Merci d’avance pour votre aide ! 😊 

PS: j'utilise un cDAQ-9178 pour connecter mon DAQ

Hi everyone,

I’m reaching out for a bit of help. I just started learning LabVIEW this week, and I’m trying to generate a ramp signal that I send to a NI-DAQ 9263 (I’m reading the output using an oscilloscope).

My goal is to be able to choose how many ramp patterns I send, set the Vmin and Vmax values, and eventually select whether the ramp is only positive, only negative, or alternating.

The issue is that even though I can successfully generate the ramp (the waveform looks correct at the output of the "waveform" block), nothing comes out of the DAQ — I see no signal on the oscilloscope.

Does anyone have any ideas or suggestions?

Thanks in advance for your help! 😊

P.S.: I’m using a cDAQ-9178 to connect the DAQ module.

[aeastet]

Are you trying to generate this signal only once or do you want it to persist on the oscilloscope? You did not give much information on what the ultimate goal of this project will be.

[dsb@NI]

Your code stops the task before the requested number of samples has been generated.

First, wire the samples per channel to generate to the DAQmx Timing VI.

Second, insert DAQmx Wait Until Done VI after DAQmx Start and before DAQmx Stop. 

modified generation code:

acquired signal:

[MABADIE63]

 My goal is to generate a ramp with a minimum and maximum value (Vmin and Vmax), and to choose whether it's increasing (positive) or decreasing (negative), as well as to select the number of ramps to generate. For example, if I choose four, then four ramps are generated

[MABADIE63]

I will try that on Monday ( I don’t have the DAQ with me now) thank you very much, I hope it will work

[MABADIE63]

I tried it and it does work BUT it take a long time to be create by the NI-DAQ (5s) and when it's done it doesn't go to zero any idea??