thermistor MAX

[schi86]

Hi,

I' m trying to calibrate and take measurements with a thermistor YSI 44033. I' m using PCI6034E, connector block SCXI-1121 and terminal block SCXI-1321. I' m creating in MAX a NI-DAQmx with internal current excitation and 2-wire configuration, when I' m trying to run the project, I have an error -200077 occurred at DAQ Assistant. I have set excitation of scxi1121 and scxi1321 in current mode by replacing the jumpers at the board as I have read in the manual. 

error -200077:

Error -200077 occurred at DAQ Assistant

Possible Reason(s):

Measurements: Requested value is not a supported value for this property.

Property: AI.Max
You Have Requested: 100.000000
Valid Values Begin with: 160.641471
Valid Values End with: 245.871833

Channel Name: Temperature

I would be grateful if you help me!

[JÞB]

The property AI.Max is in scaled units (in this case Degrees C) Write a value greater than 160.xxx

[schi86]

Thanx Jeff,

The problem is that even if I write a value greater than 160,xxx and lower than 245,xxx, the result of the measurement it's always -273,15!

I think that the problem may be in the thermistor coefficients or in the calibration of the SCXI1121. I' m right? Any other idea?

Thank you for you help 

[JÞB]

-273.15 C = 0 Kelvins.  So you are reading a properly scaled 0V input and the calibration seems pretty close.  Some physical wiring is not correct but the BD Wiring seems to work.

[Brad_K]

Hi schi86,

Check the SCXI-1121's gain jumpers and the corresponding module properties in MAX. If the gain is too high, that limits the voltage range and consequently the range of temperatures you can measure.

Brad