USB-6008 How to select analog input range?

[Anders E]

I’m just bought the USB-6008 board and I have got it running. I can select channels and chose differential or singe ended coupling and do measurements, so far so good. The problem is that it seams like I can't change input range (I know it should work only with differential coupling). I doesn’t matter what I chose, I have a quantification of 5mV and a range of +-10V

My setup in NI-DAQmx is:
Channel:1 Max:1 Min:-1 Coupling: Differential
Task timing: On Demand

With that setup I can measure and get correct reading of the voltage of a 9V battery,
Wouldn’t it saturate at about 1V ??

(I use Labview)

/Anders

[Anders E]

Now I have got the input range to work, the problem was that LabView don't update changes in the task made in "DAQmx base configuration".
Why this? And how can I manually force an update without restarting LabView?

Description of how I can reproduce the problem:

Create a AI task with range [1V -1V] , Differential, “On demand”, Save and Exit
Start Labview and do one measure using “DAQmxBase Start Task” and DAQmxBase Read
Start “DAQmx Base config…” and edit the range to [10V,-10V] Save and Exit
Run the program in LabView, result: no change the range is still +/-1V ????
If I save the VI and close Labview (just the VI is not enough) and start LabView again and open the same VI, now the range is +/- 10V.

Im using LabView 7.1

[Malcolm]

You have two options:
1) Launch the NI-DAQmx Base Task Configuration Utility for the LabVIEW Tools menu instead of the start menu. Running the tool directly from LabVEIW will keep the configuration data live.
2) Use dynamic tasks (as in the dynamic examples). You will need to add Create Task, Create Channel, and likely Timing VIs to your program.

Hope this helps.

[Anders E]

Thanks for your answer, I think I go with the dynamic option.


/Anders