EXFO FTB -5240S/5240BP Optical Spectrum Analyzer for FTB 500 (NS-1434) - Manual (Page 85)

Setting Up the Instrument in WDM Mode
Optical Spectrum Analyzer 77
Setting Up WDM Analysis Parameters
6. If you want to apply the above settings to the active trace, select the
Apply to active trace and re-analyze option.
7. Press OK to save the changes and close the window, or press Cancel to
exit without saving.
Note: The application displays a message if more than 1000 channels are added.
You can exit the Analysis Setup window only after deleting the extra
channels from the channel list. You can delete the channels manually as
required.