DAQ Assistant sampling

[Kneeman]

Hello,

I wrote a .vi to read 7 voltage channels from a CB-68LP, put them through a matrix, and write the results to file (along with a visual display). My issue is I am trying to sink the data up with a different system taking complimentary data (different computer). This secondary information is sampling at 100Hz. I woud like to have my data points from this .vi align with my data points from the other unit. I have used a trigger voltage (linked to the other unit) to be the start/stop for my .vi to be writing its data points. I have attached the .vi. Do i need to use a loop at all (i'm not that savvy with them so i haven't used one yet)?

Thanks for your help.

[sankah2k]

Hi Kneeman,

Could you please post your VI saved in version 8.5.1? I can help take a look.

By the way, in your application, are you required to sample continuously (until the program is stopped) or it is a one time sampling (sampling of a fixed number of points)? How are you currently aligning the data from both the VIs together? Are you doing some post processing from the saved files in the two computers?

Hope to hear from you

Cheers!

Sanka

[Kneeman]

I would like to sample continuously, yes, and i am doing post processing from the saved files also. I suppose my problem more simply put is that i really am just not getting the amount of data points for a given time that i would expect. If you can also figure out how i can add a time stamp to each data point that would be great also. 

Thank you so much for your help,

Kneeman

P.S. I believe i saved the VI for you correctly!

[Burt_S]

Hello,

There are a couple of things wrong with your program.  First of all, your While Loop is set to continue when true, and you are constantly writing a false to it.  This is causing your DAQ Assitant to only run once.  However, once you fix this issue, you are going to run into the problem of needing to either do your data processing inside of the loop, or allowing the loop to create an array with all of your data so that it doesn't just send out the last set of data it acquires.  I think your best option here would be to start slow by writing and testing one piece of your software at a time.  First work on the data acquisition and make sure you are able to read the amound of data you want at the rate that you want.  Then worry about processing and saving that data.  Hope this helps.