EXFO FTB-7000 OTDR Series for FTB-500 - Manual (Page 240)

Using the OTDR as a Light Source or VFL
226 OTDR
To identify fiber faults visually:
1. Clean the connectors properly (see Cleaning and Connecting Optical
Fibers on page 26).
2. Connect the fiber under test to the VFL port.
3. From the main window, go to the Source tab, then select VFL.
4. With the Modulation dial, select 1 Hz or CW. Choose 1 Hz to set the
VFL to 1 Hz pulsed output, and CW to set it to a continuous output.
5. From the Auto-Off box, select the duration after which you want the
laser to shut off. If you want to deactivate the automatic shut-off, simply
select Disabled.
6. Press Start to send the VFL signal. You can stop the VFL signal
emission at any time by pressing Stop.