Load cell simulation with PXI system

[mashman]

Just curious if any of you have tried to do this...
I'm using LabView and my PXI chassis to test a board that interfaces with a load cell. The load cell is 2mV/V with a 3volt excitation voltage so full scale would be 6mV. I was hoping to do a sweep in increments of 1mV. So two signals S1 and S2, e.g. S1=2.000 S2=2.001, S1=2.000 S2=2.002, then S2=2.003 etc...
The only analog outputs I have are the two 12 bit outputs form the 6040E MIO card...not enough resolution.
I was thinking maybe I could buy some sort of accurate multiplying DAC and control it with the Digital lines from my PXI system. Anyway I was just curious if any of you guys and gals had done something similar...or maybe there is a low cost pxi card that I could use...but
I doubt it...my budget is limited right now.
Thanks and regards

[Spencer S.]

Mashman,

Have you considered using an external reference to increase the resolution of the analog output channels on your 6040E? You could definitely get your code width below the 1 mV level that your application requires. Below are links to a couple of documents that discuss the use of external references:

Resolution of Analog Outputs

Outputting a Voltage Using an External Voltage Reference

Good luck with your application.

Spencer S.

[mashman]

Ah, thanks Spencer. I can use an external 3.3V reference and get the resolution that I need.
Thanks!!