Fred, The problem with your implementation is that you're only monitoring the value of the first cell. You will need to monitor the values of the entire row and compare them to their previous values to know when they changed, because you should only take the timestamp then.
Additionally, I'm not sure I understand. Does you file have only 3 lines? Is it possible it will have more? Could they come in a different order?
I think what I would do is use Add Array on the original array coming into the loop and if that number has grown I would add a time stamp.
Last thing, you're using shift registers, but you're not doing anything them. You will have to use more shift registers to accomplish this. If you don't know how they work, check the example finder - there should be a few examples.
In general, I suggest you try searching this site and google for LabVIEW tutorials.
Here is one you can start with. You can also contact your local NI office and join one of their courses. In addition, I suggest you read
the LabVIEW style guide. It has some good tips on design.
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