Best Method for Saving Data to File?

Hi,
We're using labVIEW 2009 to acquire data from our instrument. In the past we have used the "write to labview measurement file" express configuration tool to save data to a file. However we had some issues with our VI - occasionally we would lose data or column headers somewhat erratically and were never able to sort out the problem. We would like to rewrite our VI with the best possible solution.
Here's a summary of what we would like to do:
Save 30 variables at a rate of roughly 1 Hz. We would like one set of column headers per file so that the data can be easily imported into labVIEW with the variable names intact. We will be collecting data continuously, so we would like to divide the data into 3-4 files per day. Ideally, the program to start new files at the same times from day to day and the filename could be configured to include the date and time/file number.
I am hoping that users can provide a little feedback about methods that were most successful and reliable. From what I have read there are a few different ways to do this (express VI, tdms, "write to text file"). Any thoughts or relevant examples would be quite useful for us!
Thanks for your help!

Meg T wrote:
Is it correct to say that in your method, the indexing results in building up the data into one large array of data before saving it to the file with the column headers and filenames appended? If we are writing data at 1Hz for 6 hours of time, will we run into an issue being able to store all the data?
Yes the indexing will build up one large array. If this is a problem due to array size and memory, you will have to write more often. You can write every second, that should not be a problem. You should still write the column names to the file first, and have the append input set to False (or nothing wired in since the default is false). This will create a new file with the headers only. Then the data write has a True wired in so that the append takes place. If running for 6 hours and gathering data once per second, your array will contain 36,006 rows of data. I'm not sure if that would cause a memory problem or not.
Meg T wrote:
it also seems difficult to incorporate headers into express VI if you are writing the data continuously as a part of a loop with the "append" option.
If you write the headers before the loop as I have shown, and use append inside the loop, you will not have problems.
- tbob
Inventor of the WORM Global

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MUYconfundido wrote:
I am in the process of embedding 3 mp3's into a PDF to submit as a portfolio. The PDF also has text, and two scores included, and with the 3 embedded mp3's it can't be more than 10mb.
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I bounced out the three projects into wav's. Now I am using Switch for Mac to compress them down to smaller Mp3's.
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!http://farm5.static.flickr.com/4084/4996323899_071398b89a.jpg!
Two of the recordings sound OK at that size, but they are just MIDI(one project is piano and string quartet, the other is just piano- all software instruments. The recording that combines MIDI and Audio and has more tracks (three audio tracks and 10 Midi/software instrument tracks)and sounds completely horrible if I get it under 5 mb as an mp3. The problem is that I need all three to equal around 9mb, but still sound good enough to submit as a portfolio for consideration into a Master's program.
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======
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