EXFO FTB -5240S/5240BP Optical Spectrum Analyzer - Manual (Page 143)

Setting Up the Instrument in Drift Mode
OSA 137
Setting Up Acquisition Parameters
8. To test your parameters, return to the Acquisition tab. Press Trial Scan
to perform a trial acquisition.
When a trial acquisition is running, the Start button is disabled. You are
notified that the acquisition is in progress in the status bar.
The trial scan is performed using the analysis setup parameters. When
the acquisition is complete, the resulting acquisition is displayed in the
WDM Graph tab and Channel Results tab. The Channel History tab
displays results as if only time 0:00 was available. The other drift mode
tabs are empty (Dashboard, Channel Graph).