strain measurment and write to file with NI9237

[lopez]

Hopefully this lab view VI can help some of the novices like myself to acquire strain using the NI9237 and write to a file.  The example VI available from NI "Cont Acq Strain Samples (with calibration)" is fine for sampling data and viewing on a chart, but you need to add your own elements if you want to logg data or write to a file.

Since aquistion is continuous, reading and writing data must be done at discrete intervals rather than continuously, or, you will end up with a very large file that can not be easily handles in excel. Also, data gets acquired in "packets" of several samples for each channel, so even if you put a write function within a case structre, as I have done ,and you don't convert the data you get that whole "packet" every time the comand writes to file. Again, you will end up with a lot more data points than you would like.

Though the top level VI is pretty simple, it took me some time and help from many folks for me to figure out what was going on.  I thought I would share.

Thanks to Sandra T, Jarrod B, Kyle B, Marc A, Herbert E and Jesse O. for your help

Next goal is to acquire voltage from a different Daq card, convert to load and graph and write load vs. displacement.

hopefully the attached files are the correct method so the VI fuctions with its sub-VI's.  If not let me know.

Regards,

Alfonso

[Jesse_O]

Alfonso,

I'm glad you got your application running.  It is also nice that you are wanting to share your code.  NI is currently testing a new system that allows community members to share code.  If you like, you can also submit your code here.

Regards,

Jesse O.
Applications Engineering
National Instruments

[lopez]

Jesse,

the link to "here" does not seem to be functional. it opens up a copy of the message board.

Alfonso

[Jesse_O]

Sorry about that.  I linked the wrong page in my browser.  The actual page can be found here.

Jesse O.