In order to collect data for a fluorescent experiment, I need to extract only the data when the pulse(red) goes off. In this case I would like to collect only the data in the segment of 2 green lines; i.e. once the pulse goes OFF.
The simple TDMS viewer isn't always the best viewer. It is quite limited and things like graph settings can't always be changed. In this case I think you can right click and change a few things but I don't have access to it right now. You can try an improved viewer called Scout X which is free (has a pro version). The graph functions are more customization and you may have more luck. If that doesn't work for you, you can read the TDMS file yourself with LabVIEW or some TDMS DLLs NI has published to get the raw data that you can then operate on.