myDAQ: Decreasing analog output delay

[Manuelvl]

Hello everyone,

I hope you guys are doing well. My issue is the following:

I am trying to read an analog voltage and then I want to output the same signal through the analog output. The goal is to verify the amount of delay that I would have in an application where I would measure voltage and currents.

My problem is that I get a delay of around 35-40 ms between the input and the output. Do you guys know if this is due to the USB interface? Is there a way to speed up the process?

The input is a 50 Hz sinusoidal signal. The current vi and screenshot are attached to this message. If you guys see any mistakes please let me know, I am starting and I would appreciate any programming tips.

I am new to LabVIEW so I am not sure about my results. This is the first time I work on a signal processing application.

I already checked some older threads about the same issue but I could not find a conclusive answer.

Thank you for reading.

[adena.l]

Hi Manuelvl - So you are trying to read data from an analog input and then immediately output this data through an analog output? There is going to be latency because you are trying to read it in through the USB bus, process the data, and then output it again through the bus. Can you tell me more about your application and why are you trying to do this?

[Manuelvl]

 Hello adena.l,

Thanks for your reply. I am gonna be using these signals for a feedback control scheme in a ac/ac converter system. So for now,  I just wanted to verify how fast I could regenerate the signal through myDAQ. 

Thanks a lot!

[adena.l · Accepted solution]

Hi Manuelvl - That is going to be dependent on a lot of things like the traffic in your USB bus and your operating system.  A delay of 30 - 45ms would be expected for a myDAQ which is connected through USB. 

[Manuelvl]

Thanks a lot for your reply Adena!