How to get input from strain gauge using NI 9219 and labview FPGA module??? Pls help.......

[abhilash]

Can somebody help me by explaining hw to take the input from a strain auge using cRIO and FPGA??? I am using NI9219 universal module.But it gives me some stupid numbers which have no relation with the values from strain gauge bridge output??? Can anybody out there,help me to solve this problem...Or just tell me what are the things that I should take note in this matter.Where can I get more informations???

Message Edited by abhilash on 07-05-2007 02:40 AM

[abhilash]

Now I am using the TEDS input for the strain gauge output....Is it correct???

[Yi Y]

Hi Abhilash,
What kind of reading are you getting from your strain gauge?  Were you able to read a known input voltage and get a correct number?  What type of strain gauge module do you have (quarter bridge/full bridge).  Were you able to look at the Analog Input shipping example to see how it's done? The module takes voltage readings, and you would basically need to convert that voltage reading into a strain reading based on the specifications of your strain gauge.  Is the TEDS you are using specific to your strain gauge? How are you using the TEDS?
It would be helpful if you could provide more information about your set up, or possibly attach the VI to show me how you are reading your strain gauge inputs.
Thanks!

Yi Y.
Applications Engineer
http://www.ni.com/support

[abhilash]

We have to measure the force exerted on a metal plate.

We are using fullbridge configuration to measure this.

No,  It's not responding to any signal,although  the program shows some values that is not related to the input.

and about TEDS i connect the output of the full bridge to the Channel zero(CH0)of NI 9219 module.

From where can I find the example that you mentioned??

I am attaching the program that i write...

and could you tell me how to solve the error 1430-"The path is empty or relstive.You must use an absolute path."

[Yi Y]

Hi Abhilash,
The examples I mentioned can be found when you are in LabVIEW, go to Help->Find Examples->Toolkits and Modules->FPGA->CompactRIO->Module Specific->Analog Input.
There you can find some examples specific to 9219.
Where are you getting error 1430?  This probably means you are trying to open a file with a file path that's either not there or it's not in the full path form (e.g. C:\your_folder\test_file).
I would suggest running the example codes and to just take in voltage of a known voltage source (a battery, for example), and see if you get the correct result.  If that works, use the code and integrate TEDS. Let me know if this helps.

Yi Y.
Applications Engineer
http://www.ni.com/support