Reading a thermocouple on a PCI-6281 using an SCB 68

[TheGeeze]

Eli,

I am connected to AI1 via channels 65 and 31.  I am not connected to AI Ground and I am sampling using differential mode.  I have included two screen shots.  One of my T-type thermocouple voltage change in test panels, and another of my temperature fluctuation using a Task in MAX.

I am not sure what version you have installed, but I cannot imagine why the installation from your disk would not allow  you to create tasks.  My thought is that something went wrong somewhere during the installation.  I would first try measuring a known voltage and/or different ports to see if that yields anything useful.  

[EliG]

Thanks for the graphs Ryan, they were very helpful. I finally fixed the issue by:

1) Getting new thermocouple wire and thermocouple terminals from Omega

2) Hooking up to a different analog input port (AI4) in differential mode

I now get a thermocouple signal, although it is pretty noisy (+/- 3 degF) even with 100kohm resistors to AIGND from both the positive and negative analog inputs.However, this accuracy with some avveraging will be good enough for mypurposes, thanks!

[TheGeeze]

I see similar noise as my set up.  There is no other signal conditioning on the board besides cjc.  Most thermocouple modules have some amplification and filtering that help eliminate some of the noise.  I see similar noise as my set up.