EXFO FTB -5240S/5240BP Optical Spectrum Analyzer for FTB 500 (NS-1434) - Manual (Page 103)

Setting Up the Instrument in WDM Mode
Optical Spectrum Analyzer 95
Setting Up WDM Analysis Parameters
5. If you want to apply the above settings to the active trace, select the
Apply to active trace and re-analyze option and press OK.
6. Press OK to load the configuration and close the window, or press
Cancel to exit without saving.