iam getting an error while slecting more than 2 channels in ni 9264 in labview iam using default ni labview examples

[AJAYY06]

“I am using an NI 9264 (DSUB) module to generate a 16-channel AC signal. The sample rate is set to 25 kS/s with 15,000 samples. When I observe the output on a CRO/oscilloscope, the waveform appears stepped instead of smooth. Is this behavior expected for the NI 9264, or am I missing any configuration or filtering settings?” i paste the vi below that iam using

[AJAYY06]

what should i change when i use more that 1 channels to generate the analog Ac signal

[altenbach]

You only have one channel because the "output array" input (I am sure you could give it a better label!) only has one element and you are only creating 1000 samples, not 15000. Are you using "continuous run" to run this? that would be a bad idea!

Why is the "offset" control inside the loop? Are you expecting it to change during execution of the FOR loop?

Can you show a picture of your definition of "stepped"? That terms is a big vague.

(Sorry, I am not commenting purely on the software, because I don't even have DAQmx installed. I am sure somebody else will give more insight)

[Bob_Schor]

Hello, A-Jay.

     You describe yourself as a LabVIEW beginner (we could tell that because you didn't properly spell "LabVIEW").  How many days/weeks/months have you been studying LabVIEW?  Are you taking a class, with exercises using LabVIEW, or are you trying to learn it by yourself (perhaps with viewing some YouTube videos)?

     You seem to have found the Examples that ship with LabVIEW, and have chosen the "Voltage - Continuous Output.vi" example, which shows it can run on the NI-9264 and NI-9264 D-sub.  You seem to be running LabVIEW 2020 (any other details you want to give us?) -- I opened your code in LabVIEW 2024 Q3 (64-bit).  If I chose the D-sub version, it immediately "errored out" (not sure why).  I didn't explore any further.

     You say "The sample rate is set to 25 kS/s with 15,000 samples."  I don't see that in your code.  Your code seems to be using a Sample Rate of 1000 S/s to generate a Sine Wave with a frequency of 10 Hz (so 100 points per cycle of sinusoid).

     Do you know anything about debugging LabVIEW code?  About using a probe to examine the data on a wire, Highlight Execution to watch the data flow through wires and show their values?

     Have you examined what the "data generation step" (from Output Array input to Waveform Graph output) does if run just by itself?  Do you have classmates or instructors to whom you could discuss your work?

Bob Schor

[GerdW]

Hi Ajay,

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@AJAYY06 wrote:

what should i change when i use more that 1 channels to generate the analog Ac signal

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Maybe you should start with reading the specs of your NI9264 module!

It clearly says "max 25 kS/s per channel", so why do you intend to go to 250kS/s???

And why do you need to start (atleast) 2 threads for the same/similar problem? Keep things in one place!

Didn't you learn that lesson 2 month ago?

[altenbach]

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@AJAYY06 wrote:

what should i change when i use more that 1 channels to generate the analog Ac signal

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Istead of chaging the index to 1, just expand the array so you see as many signal configurations as you like.

(Personally, I would right-click the cluster and "autosizing...arrange horizontally" e.g. as follows.

Here's how it would look for five signals.

I recommend some basic tutorials. 

I cannot comment on the rest of your questions.

[AJAYY06]

"Should I use LabVIEW's built-in example VI as a starting point and configure it for my specific requirements, or write custom code from scratch? I've uploaded my example VI—can someone help modify it accordingly? for each channel i want to use the different frequency

[ajayyy06]

Hi,

I am using an NI 9264 analog output module and I want to generate an AC signal on all 16 channels.

Currently, I am using the DAQmx Write – Voltage Continuous VI. I have configured the sample rate as 25 kS/s per channel while generating the AC waveform on all 16 channels. However, when I observe the output on a CRO (oscilloscope), the waveform appears stepped instead of smooth.

Additionally, when I increase the signal frequency above 5 kHz, I notice unwanted disturbance/noise in the output signal.

I have already reviewed the NI 9264 specifications and followed the recommended settings, but the output waveform is still not smooth.

Could someone please help with the following:

• Suggest the correct sample rate required to generate a smooth AC signal on 16 channels

• Recommend a suitable LabVIEW VI for this application

• Or provide a sample LabVIEW code for generating a proper AC waveform

[GerdW]

Hi Ajay,

wow, two new threads (and even a new user account) for the very same topic - even though you were reminded to keep things in one place?

Don't you want to listen to advice?

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@ajayyy06 wrote:

Additionally, when I increase the signal frequency above 5 kHz, I notice unwanted disturbance/noise in the output signal.

---

So you output less than 5 samples per period and you wonder about "disturbance"? Really?

Have you had any relevent signal theory lessons in highschool/university?

[AJAYY06]

I didn't remember whether in university lesson present or not .

Can you answer if it