AnalogWaveformSample timestamps jump around

[Mojo Hand]

Hello!

We are using the AnalogIn on a PCI-6071 and the .NET DAQmx tools, and we're seeing strange behavior in the timestamps of the returned AnalogWaveformSample's. While acquiring data, every 5-10 seconds the timestamps for a block will suddenly jump backwards in time ~60 seconds, and then when returning the next block they jump forward again by a similar amount. 

The settings used are: 

sample rate=6000

Sample Quantity Mode = Continuous

samples per channel = 600

I've attached a spreadsheet(csv) that shows what I mean. First column is timestamp in microseconds, second column is dt. Look at the second column, which shows the effect I'm talking about.

We have used the PCIe-6323 and USB-6343 and do not see this. Any ideas?

[Marek S. · Accepted solution]

Hi,

I would like to present you some ideas which come into my mind that can help you to fix this unexpected behavior:

Try to check the version of NI-DAQmx driver if it is up to date. You can find your current NI-DAQmx driver version in Measurement & Automation utility and then in My System->Software->NI-DAQmx Device Driver x.x.x. The latest driver version for Microsoft Windows OS is 9.4, you can find it in NI-DAQmx driver download.

Make sure that it is not related to performance issues on PC, when you are running the data acquisition.

If all of above is still not solving the problem, try to create new simulated device and repeat the data acquisition with this simulated hardware.

Please let me know if the problem still persists and if so, I would like to ask you to send me your code (VI).

Marek S.

[Mojo Hand]

Update on this: moved card to another PC, did not have the timestamp issue. Looks like the system clock of the first machine is wigging out. Thanks for the help!

[Manuel9]

Hello!

I'm using a usb6008 and multipleAnologIn. But I don't know how to get the timestamps of each AnalogWaveformSample's. Can you please post the code line where you get the timestamps??

thanks