DAQmxReadAnalogF64 Initial Data Problem

[jayrandom]

I am having problems with DAQmxReadAnalogF64 implemented using CVI.  The function compiles and runs without errors, but there first approximately 10 points are below the expected value and look to be exponentially approaching that value.  The number of points seems to be independent of data acquisition rate which suggests the problem is related to my software implementation as opposed to the hardware or the signal itself.  When sampled using the test panel, no such errors occur.  I am using LabWindows CVI version 7.1 and a NI USB-6259 in differential mode.  Thanks for any help.

100Hz

 100KHz

Test Panel

[ManLongAtNI]

Are the data points in the test panel an accurate representation of the signal being measured? If so, have you sent the same sampling properties in your code as you configured in the test panels?

Regards,

Glenn