help!!collect data at particular time intervals/cycles

[lax]

Hello,

         I have to write a program to collect data at particular time intervals/cycles. We collect data at 100 points per cycle for 5000 cycles. But due to the huge volume of data I have to collect at certain intervals ( say cycles 1-10, 29-31,49-51 .... 3999-4001 .. 4999-5000). I would appreciate if anyone could please help me with this program.

Thanks and bext regards

lax

[RavensFan]

Can you provide a little more detail about your application?  What hardware are you using?  What is the data acquisition rate that you need?  How do you determine when one cycle ends and the next begins?  Are you collecting all 100 samples for a cycle at once?

How you collect the data (1 sample vs. N samples vs continuously) and how fast they come in will determine whether the code should be hardware timed or software timed, and how to process the data (in the acquisition loop or an a separate parallel loop).

[lax]

Hello,

          Thanks for your reply. I have just started with LABview and the program I am dealing with was written by someone else. Anwyays, we are using  a NI PCI 6259 data aquisition card and NI SCXI (these are data aquisition for each channel I guess). We collect the load and deformation data (using LVDTs), which is the primary purpose of the project. We apply a load for 0.1s and rest for 0.6s. We collect the data at 100 points per second for the whole test (which runs for either 90minutes or 5000 cycles). We just start the test and collect data all the way through and the rate of collection remains the same throughout the test.

          As for finding out when exactly the cycle starts and ends. We will have to find that with time I guess. We plan to collect data for the first 100 cycles, then for 2 to 3 cycles every 50 or 100 cycles (which may increase towards the end of the test, i.e. we might jump from 3000 to 4000cycles).As for collection we collect the data 1sample at a time.

         I have attached a part of the program which measures all the data (which is part of another program). Some VI's might be missing (DAQmx start task, DAQmx stop task, DAQ mx read). Please let me know if you have any solution. Thanks again.

Regards

lax