If is selected, the data in the plot(s) will be exported after a measurement is performed or opened. The filename of the text file depends on if the measurement is saved to file or not. If the measurement does not have a filename, it is saved under the default folder given in Measurement-> Saving Defaults.... The filename is set to “PlotMeasFromMem<Measurement number>.txt”. If the measurement has a filename, it is saved using the measurement filename but with the extension .txt.
This is useful for batch-processing, e.g. if you want to compute the frequency response of several measurement files and send the data to a text file.
To do this, go to File->Open... and mark the measurements files you want to process (use the shift-key to mark multiple measurements).
Click the button shown below to open the export options. See the Edit->Copy Data Options… section for more information.