Selecting Auto Or Manual Otdr Mode; About Launch And Receive Fibers - Fluke OF-500-01 OptiFiber Technical Reference Handbook

Selecting Auto or Manual OTDR Mode

You should use Auto OTDR mode when certifying
cabling with the OTDR.
From the HOME screen, press
OTDR or Manual OTDR from the popup menu.
You can also switch between test modes by selecting Auto
OTDR or Manual OTDR from the FUNCTIONS menu.
In Auto OTDR mode, the tester automatically selects
settings based on the length and overall loss of the cabling.
This mode is the easiest to use, provides the most
comprehensive view of the events on the cabling, and is the
best choice for most applications.
Manual OTDR mode lets you change settings to optimize
the OTDR for displaying specific events. See "Using Manual
OTDR Mode" on page 3-45 for details.
Tip: To see the settings used for an OTDR test, press C
View Details on the OTDR SUMMARY screen; then press
A OTDR Settings. The settings used may be slightly
different from the nominal values selected on the OTDR
tab.
Note
A
Change Test. Select Auto
Setting Up for OTDR Testing

About Launch and Receive Fibers

Launch and receive fibers let the tester measure the loss
and reflectance of the first and last connectors in the
cabling, and include those connectors in ORL (optical return
loss) measurements. Without launch and receive fibers, no
backscatter is available before the first connector and after
the last, so the tester cannot measure the connectors'
characteristics.
If the first or last connection in the cabling is bad, and you
do not use launch and receive fibers, the OTDR test may
pass because it does include measurements from the bad
connection.
OVERALL LOSS and FIBER LENGTH include the loss and
length of the launch and receive fibers, unless you use the
launch fiber compensation function.
Fluke Networks recommends that you use launch and
receive fibers. You should also use launch/receive fiber
compensation to remove the effects of these fibers from
the OTDR measurements.
W
For testing cabling with angled physical contact
(APC) connectors, use only launch/receive fibers
with APC connectors at the end connected to the
cabling. Other connector types will cause large
reflections that may invalidate your test results.
Using the OTDR
Caution
3
3-3