AO0 dc offset by ~7mV

[YZ]

Hello,

my PCI-6036E card has an analog output offset by about 7mV (measured by
a hand-held DMM). This is a problem for us. How can I zero that offset?

THanks

YZ

[Nicholas_B]

Greetings YZ,

First you will want to make sure that the device passes the Self-Test in MAX.  Open MAX, highlight your device, and first click the Reset Device button, then the Self-Test buton (ensure both are successful).  After that, test to see if the offset is still present.  If so, it sounds like your board needs to be calibrated...there are several ways to perform the calibration.  The easiest would be to perform a self-calibration on the device.  This can be done in MAX or LabVIEW.  In MAX, right-click on the device and choose Self-Calibrate.  From there, follow the instructions in the wizard.  

If these do not eliminate the offset, we might need to take the calibration a step further by using Calibration Executive or sending the device to NI for internal calibration.  Please let me know if these options do not eliminate the offset...

Regards,

Nicholas B, National Instruments

[YZ]

Nicholas B wrote:

> Greetings YZ,
> First you will want to make sure that the device passes the Self-Test in MAX.&nbsp; Open MAX, highlight your device, and first click the Reset Device button, then the Self-Test buton (ensure both are successful).&nbsp; After that, test to see if the offset is still present.&nbsp; If so, it sounds like your board needs to be calibrated...there are several ways to perform the calibration.&nbsp; The easiest would be to perform a self-calibration on the device.&nbsp; This can be done in MAX or LabVIEW.&nbsp; In MAX, right-click on the device and choose Self-Calibrate.&nbsp; From there, follow the instructions in the wizard.&nbsp; If you wish to perform the self cal in LabVIEW, refer to the instructions in <a href="http://digital.ni.com/public.nsf/websearch/51A15DD0CE9491B586256A1D00631940?OpenDocument" target="_blank">this KB</a>.&nbsp;
> If these do not eliminate the offset, we might need to take the calibration a step further by using Calibration Executive or sending the device to NI for internal calibration.&nbsp; Please let me know if these options do not eliminate the offset...
> Regards,
> Nicholas B, National Instruments


Nicholas,

thanks for you advice. It turns out it was not DAQ fault, it was a good
ol' ground loop. I think I fixed it, but will have to check more carefully.

BTW, what version of MAX is current? On my 2.2 I don't have all those
options and buttons that you mention in your post.

Thanks again

YZ

[Nicholas_B]

Greetings YZ,

Glad to hear that you've narrowed down the problem.  If it persists, please do not hesitate to post again.  The most current version of MAX is 4.1 and can be obtained by installing any of our current NI drivers, available here.

Regards,

Nicholas B, National Instruments

[Gene Civillico]

hello YZ -

this is a longshot but I am seeing a very similar offset and suspecting a ground loop as well.  I wonder if you could tell me how you fixed yours, i.e. how did you access the card ground in order to tie it to the other ground?

thanks,

Gene

[Neal M]

Hello Gene,

It appears that your grounding issue was already addressed (in this thread).  If I am incorrect and you are still having issues with this, please post back and I will try to help you out!