how to get rid of DC offset (NI PCI-6025E and LABVIEW7.1)

[SilverHawk]

hi all,

I've been using this NI PCI-6025E card and LABVIEW 7.1 to do some Voltage DAQ of thermistors.  

The problem is, i'm getting a DC offset of abt +0.25 in my display graphs and report printouts of the DAQmx.

 I've tried to trace the source of this but in vain.

The output of my circuit is 2V but  the display and print of reads abt 2.25V. I've tried to run the test during the creation of DAQ-assistant, and the readings are constant to the voltmeter. But when hooked and displayed on a waveform/numeric display, there seem to be a +0.25 V of set in the readings. Can anyone help? What can i do to get rid of this offset?

rgd

SILVERhawk

[Hal_L]

Hi Silverhawk,

If you can acquire the correct 2 Volt values in the test panels of the DAQ assistant, then there is something that I want you to try. Create a task in MAX to acquire your data and run a test panels to make sure that you are receiving the correct values.  If these values are correct, then go to LabVIEW and place a DAQmx Task Name Constant on the block diagram. Select the task that you created, right click the Task Name Constant, and select Generate Code >> Configuration and Example.  Run this program and let me know if you are now acquiring the correct data.

Regards,
Hal L.