This is related to a previous post (http://forums.ni.com/ni/board/message?board.id=170&thread.id=304755&view=by_date_ascending&page=1).
Since I didn't get it resolved I am posting and refrasing the issue, with a more simple/basic question. (you don't need to read the previous post, I made simpler VIs for this question)
I have a program called "
TakeData" which reads analog voltage from 1 channel, displays the data in a Chart and puts it into a Measurement LVM file "CollectedData"+date&time.
* the "Write to measurement file" uses the "save to multiple files" option so that it can create one file per measurement, with the date&time appended to the name.
* to run it, you will need to change the channel to something you have in you DAQ system....you don't need to send a voltage, since nothing is done with that data.
Another VI called "TestRead" reads the LVM file, displays the data in a Chart and saves the data in a second LVM file "NewOutput"+date&time.
* the "Write to meas. file" is setup in the same way as the one in "TakeData"
The strange behavior:
For Example:
If you run the "TakeData" VI for say 5 seconds, it will save approx. 450 records (starting at 0.0) collecting several samples per second (approx. 450/5 = 90 samples per second). If you open the LVM file you can easily see this in the first column of data. Also, the Chart displays data for 5 seconds. Data will be saved in the "CollectedData" LVM file.
Later, if you run the "TestRead" VI and open the LVM file previously created, not only it will take much longer to read (more than 5 seconds...,maybe 10s), but the time in the graph will be off and the "NewOutput" LVM file created will have times going from 0 to 450 (not 0 to 5seconds), so it would appear as collection time was 450 seconds, with 1 sample per second.
What's wrong?
Did I setup something improperly?
In the "TestRead" VI you'd expect that the same data it reads gets re-saved in the second LVM file......and both LVM files should match
Is something wrong with the reading then? Did it ignore the time column?
I use LV 8.2
Message Edited by emerino on
03-05-2008 11:23 AM