Upper band of Switching Frequency for Labview

[Rakesh_belchandan]

What is the time delay we should normally expect from software (LabVIEW) to hardware (any NI FPGA module such as NI 9683)?

Can we use LabVIEW program for switching frequency 40KHz to 100 KHz? Which FPGA module can support this?

What is the maximum switching frequency LabVIEW has developed devices for?

[Sekine108]

This is a tough question which doesn't really have a finite answer due to a large number of variables. But, typically it is within the microsecond range.

Make it Faster: More Throughput or Less Latency?

http://www.ni.com/white-paper/14990/en/

If you are using a cRIO you can change which frequency you are referencing from the onboard clock. The cRIO uses a 40KHz clock and you can derive a smaller or larger clock from this. This won't be dependent on the module, but more the cRIO. I am unsure if this is the same with the PXI chassis.

I am not sure what you mean in your last question. Are you referring to how long the program will take to go from 40KHz to 100Khz? Or are you wondering what the fastest frequency NI's products can handle is?

[Minions]

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@Rakesh_belchandan wrote:

What is the time delay we should normally expect from software (LabVIEW) to hardware (any NI FPGA module such as NI 9683)?

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The answer here is Windows (or whichever environment that you are using) dependent.  We have had times where contact from LabVIEW is held for seconds due to Windows addressing its internal priorities before addressing the next LabVIEW command.  If you are using LabVIEW Real-time, then LabVIEW tasks take priority over Windows events and the lag would be minimal.

[RavensFan]

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@Sekine108 wrote:

If you are using a cRIO you can change which frequency you are referencing from the onboard clock. The cRIO uses a 40KHz clock and you can derive a smaller or larger clock from this. This won't be dependent on the module, but more the cRIO. I am unsure if this is the same with the PXI chassis.

Do you actually mean a 40 MHz clock?

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[Sekine108]

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@RavensFan wrote:

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Do you actually mean a 40 MHz clock?

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Whoops! Yeah, I totally mean a 40MHz clock. 40KHZ would be silly haha

[Rakesh_belchandan]

What is the maximum switching frequency LabVIEW has developed devices for? I want to generate gate pulses (PWM) for my SiC devices. How further I can go using Labview. Can I go on 50-100 KHz range for switching?

[Sekine108]

I am still uncertain on what you are asking. Are you referring to how long the program will take to go from one set frequency to the next defined frequency? Switching from one output to the next output? Or are you wondering what the fastest frequency NI's products can handle is?

[LV_Pro]

Or are you asking how fast can you generate PWM signals on the fly? As earlier posters have mentioned, if you are running LabVIEW on Windows there is really no way of knowing, as the operating system is not deterministic, so it will have unpredictable delays. Can you describe in a little more detail what, exactly, you are trying to do. You mention FPGA, etc., but generating PWM signals is still a little too vague to begin to give you a more definitive answer.