Viavi COSA-4055 Parts list manual

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T-BERD®/MTS-2000 Modular Test Set
CWDM Optical Channel Checker (COSA-4055)
The following procedure outlines how to connect to a fiber under test, configure COSA-4055 test
setups, run tests, and analyze results with a T-BERD/MTS-2000 equipped with a COSA-4055 module.
Note: The COSA-4055 module is used to monitor wavelengths on a live network. Care should
be exercised when unplugging fibers from the network as the fibers may be carrying traffic.
Equipment Requirements:
•T-BERD/MTS-2000 equipped with Fiber Optics
Software Release V18.0 or greater
•COSA-4055 CWDM OSA Module
•Fiber optic cleaning and inspection tools
•20-meter Fiber optic patch cord (Launch
Cable)
•Optical Coupler to connect Launch Cable to
Fiber Under Test
Figure 1: Equipment Requirements
The following information is required to
complete the test:
•Type of Connectors (SC UPC, SC APC, LC, etc.)
•CWDM Wavelengths used
Figure 2: COSA-4055 Module
Fiber Inspection Guidelines:
•Use the VIAVI P5000i or FiberChek Probe
microscope to inspect both sides of every
connection being used (OTDR Port, Launch
Cable, bulkhead connector, patch cord, etc.)
•Focus the fiber on the screen. If dirty, clean
the connector.
•If it appears clean, run inspection test.
•If it fails, clean the fiber and re-run inspection
test. Repeat until it passes.
Figure 3: Inspect Before You Connect (IBYC)

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Connect to Fiber Under Test (FUT):
All fibers and connectors should be inspected and clean prior to connection, as described on page 1.
The COSA-4055 is typically connected to the FUT via a Monitor Port or splitter/tap to not disrupt
service. The COSA-4055 can also be directly connected to the common port or common fiber via a
coupler during turn up or maintenance:
Figure 4: Connecting to Monitor Port
Figure 5: Connecting to common cable
1. Inspect the COSA-4055 port on top of the test set.
2. If connecting to the Common Cable, connect the Common Cable to an optical coupler with the
same connector type and inspect the fiber end face in the coupler.
3. If connecting to the Monitor Port or Common Port on the Mux, inspect the Mux Port.
4. Inspect the fiber end face of the Launch Cable.
5. Connect the Launch Cable to the COSA-4055 port.
6. Inspect the other fiber end face of the Launch Cable.
7. Connect the Launch Cable to the coupler or Mux port.

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Product specifications and descriptions in this
document are subject to change without notice.
Launch and Configure Test:
1. Press the ON/OFF button to turn on the
test set.
2. If files are to be saved, tap the FILE Button
and tap the Project folder to view the File
Explorer. Otherwise, proceed to step 5.
3. Tap the Create Directory soft key, enter a
name for your new folder, and tap the
Enter key. All trace files will be saved to
this directory.
4. Press the HOME button to display the
Home Screen.
Figure 6: File Explorer
5. Tap the COSA-4055 icon until it is selected
and highlighted in yellow.
6. Tap the SETUP button.
7. Tap the Acquisition soft key.
8. Set Sweep to Single and tap the TEST AUTO
WDM soft key.
9. Tap the Top Menu soft key.
10. Tap the Analysis soft key. Set Signal
Threshold to Auto and Mode to
Permanent. If a splitter/tap is used to
access the signal, set Splitter Compensation
Value to the splitter loss (in dB or %).
Figure 7: Setup
Run Test:
1. Tap the START/STOP button to start the
test. The COSA-4055 will sweep the entire
CWDM wavelength range. Results will be
shown in graphical and tabular formats as
shown in Figure 8.
2. Verify that traffic is on all expected
channels, at the anticipated wavelengths
and power levels, and that there are no
unexpected wavelengths present.
Things to look for:
a. Every expected channel is present.
b. Channels are about 20 nm apart.
c. Power levels of each channel are
within roughly 3 dB of each other, or
within the relative amplitude
specification of the Network
Equipment Manufacturer.
Figure 8: Results