Most of the channels provide negative (incorrect) readings.

[Phone]

We have this Labview system for more than 6 - 8 years now. We had some problems in 2005 and got some help from you. It is about 32 channels data collection and logging unsing 10 SCXI modules connected to one board in PC. System was running fine until last Friday. So suddenly now most of the channels read some time negative numners, sometime all zero, and sometime goes all over even we are running flow thru. Please provide some support to fix it.

Thank you

Amrish Patel

727-849-9999 X 4312

[devchander]

Did you perform a self test on Your DAQ card ( to which your SCXI modules may be multiplexed) or SCXI chassis using MAX??

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So suddenly now most of the channels read some time negative numners, sometime all zero, and sometime goes all over even we are running flow thru

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Does this problem show up when you read the concerned channels from your application program( I guess you must have one) or does it show up in MAX as well??

[Phone]

Is there any way you can call me now at 727-849-9999 Ext 4312? We have an emergency and need support immidiately. Thank you.

[Matt_A]

Hello Amrish,

I believe you are in the process of speaking with one of our Applications Engineers via telephone in regards to this issue. I will post the results for other users when you and he have resolved the problem.

[Matt_A]

Hello Amrish/Readers,

After a visit from a National Instruments Field Engineer, this issue was diagnosed as a ground loop in the test fixture that was causing incorrect values.

[devchander]

Matt,

Thanks for posting a follow up

That is very thoughtful of you

Regards,

Dev