writing large files to excel

[1231]

hi folks,

i am using the write measurement block to write power calculations to excel,

however i am running a test on battery coin cells and its taking a few days before they die. so the test will be going on for abit. will excel handel this?

or is there another way to do this?

(plot power vs time (seconds), and volts vs time)

also, i am trying to get the mean power vs time. as well as the max and min values recorded over the time duration.

what is the best most efficent way to get the mean,max and min values from my output (double) ? i know i will need an array and a shitf register, but not sure how to go about it.

thanks.

[unclebump]

If you want to analyze the data after it is collected use the attached vi as a guide. If you need the values as the data is collected, there are point by point versions of the mean and array max/min vi's.

[1231]

yes,  but i need mine to run continously, for maybe 1 hour or a few days, however long the test will take. and gather values from that.

how can i implement this, what do i put into the loop, to tell it when to end?

regards

eric

[1231]

here is my vi which i want to implement this on. if it helps to understand more!

[unclebump]

I couldnt' open your file, I'm using 7.0. You would be better off using a while loop to acquire your data. This way you could stop execution based on sensor data or a stop button. It kind of depends on how quickly you are acquiring data values. You could open a file and write values to it and close it each time, or leave it open and close it at the end of the test. You could write the data into a queue, or initialize an array outside of the loop and replace elements inside the loop. Give us some more detail on the acquisition process.

[1231]

ok, here is a snapshot of my vi.

basically, from the power output node, i send this along with the current and voltage to the measurement block, and i get an excel file with time in seconds (between each sample of current and voltage) along with power and voltage.

so i can simply graph time vs power/volts, if i run the test for 20 hours, i just stop it, and check the resulting excel file, it will have all the data,

i wish to do exactly the same with the mean power vs time. but to get the mean power i need arrays, and this has me well stuck.

i can use the example you gave me and get mean, max min and send that to another excel file. which is what i want, and for it to save all the values after i stop the program (manually)

hope that clears things up as i have no idea how to get this done!

thanks

[unclebump]

Here is a new version with the mean/max/min calculated as the data is collected. Just wire these to a chart.

[1231]

thanks man, i will check this out now.

regards

[1231]

on a different note. i am using a cell module attached to a 25mm sensor node, to graph the battery vs time. but its taking ages,  the battery went from 2.3 volts to 3.5 volts. how can the voltage increase vs time? !

you can see the module under test from tyndall.ie, and search for 25mm.

best

[1231]

i attach the 'dice' to my output multiplier node right? this loop will run for 1000 counts? and send all the data in that time to the output array and then do 1000 more counts?

i am trying out that now, see how it goes.