error -200279 USB-4431 DSA Card

[ssherian]

I am using USB-4431 Dynamic signal acquisition card.  I have the program shown in the attachment.  I am trying to generate a random vibration signal to control shaker and at the same time read back 2 analog input channels. When i run my code with the full program, i get error -200279 but when i split the acquisition&generation code and put it in a stand alone vi and run it by itself, i don't get any errors.  I tried different sampling rates and samples/channel.  the one that seems to work best is when i am sampling at 60KHz and 20Ks/channel.  My requirement is to sample at 200KHz ane 20Ks/channel acquisition.  I monitored available samples/channel node and seems to keep going up until no more samples are available and it shows 0.  I need to make these 2 tasks run properly in the main program which is an event driven master/slave loops.

[Chris-G · Accepted solution]

Hi ssherian,

The USB-4431 has a maximum sampling rate of 102.4 kS/s. If your application requires a 200 kS/s you'll have to use a PCI or PXI-based DSA card with a higher AI sampling rate.

In terms of error 200279, this error is typically due to a problem with the DAQmx hardware buffer. With a continuous acquisition, a good rule-of-thumb is to have the sampling rate 10x the number of samples to read (i.e. sampling rate = 10000 S/s, samples to read = 1000). It's also possible that your computer simply can't process the data fast enough. If you are performing any complex, real-time data-analysis your computer's processor simply may not be able to keep up with the data-rate.

This KB: Error -200279 DAQmx Read Error provides an in-depth overview of error 200279, possible causes, and steps to troubleshoot the error.

Hopefully this helps,

Chris G

[ssherian]

Thanks for the help