Graph Data

[jray3475]

Hello,

I am acquiring data using DAQmx and am saving the data as .lvm file using the "Write Measurement File" option. My issue is I need to read the file and maiupulate the data with  a few equations and graph the results. One component is the acceleration; which is the rotational speed divided by time. The rotational speed is the voltage from the file divided by the motor constant of the generator. I haven't been able to read the columns seperately (1st column time, second column voltage) so I can manipulate the data. This is important because after the acceleration is found I need to use this value to find torque and graph the torque vs the original time values. Torque is (J x acceleration) / gravitational constant. (J being the mass monent of inertia, which is a constant)

I've tried several methods, but all just give me a blank graph. Any help is very much appreciated. Thanks so much iin advance for your time.

[jjcimon]

could you post the file? and an image of the graph before the saving?

jacques

[jray3475]

Thanks for your reply, the file itself is also used to automate a device with a PCI-6221 interface so it is quite large. I'm currently using excel macros to slice up the data and create two separate files, one with the time data and the other with the voltage data. There are 15020 data points in each file. This is the only way I could think of to manipulate the time and voltage data to find the 15020 acceleration, speed, etc, before bringing the data back together to form power and torque curves. I was hoping there is a easier way.... that works. If not.... is there a way to import graphs from excel? I could maybe write a macro that will calculate the required data and graph it in excel, and save the graph as a .jpg, but I would need to import the .jpg file back into LabVIEW for the operator to view. It all has to automatic... there can't be any manual manipuation after acquisition. Thanks for your time