EXFO FTB -5240S/5240BP Optical Spectrum Analyzer for FTB 500 (NS-1434) - Manual (Page 277)

Optical Spectrum Analyzer 269
10 Testing DWDM Systems
Optical spectrum analysis is the measurement of optical power as a
function of wavelength or frequency and optical signal to noise ratio
(OSNR). Applications include commissioning of a new DWDM or CWDM
link, as well as maintenance and troubleshooting of existing networks.
Using the Discover Feature
The Discover feature allows you to start a procedure to automatically build
an analysis setup (scan range, channel list, analysis parameters, etc.)
based on the signal being detected on the input port of the OSA module. It
allows you to start an automatic setup scan.
Note: Discover features is available on for the WDM and Drift test modes only.
An automatic scan is a full range single scan that locates the various peaks
from the incoming signal. Prior to this scan, the application will clear the
data used for processing, empty the channel list, set the analysis
parameters to default values (equivalent to pressing the default button in
every setup screen).
If no channel is detected with this first scan, then the graph shows the full
range scan and ends the analysis. The wavelength range will be set to
1250 nm to 1650 nm and the channel list will be empty in the Channels tab
on the Analysis Setup window.
If at least one channel is detected, then the wavelength range is set to 5 nm
before the first detected signal peak and 5 nm after the last detected signal
peak (and within the wavelength full range, 1250 nm to 1650 nm). All
detected channels are added to the channel list and the default settings are
used for all channel parameters. The channel center wavelength is aligned
with an ITU grid (200, 100, 50 or 25 GHz for DWDM). The channel width is
determined using the overlap criteria, if two channels overlap by more
I
MPORTANT
For optimal test results, you must allow a minimum warm up
period of two hours for your Optical Spectrum Analyzer before
starting your tests.