OFT-3 User's Guide Rev A 2/7/14
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Chapter 7 OTDR Operation
Table Definitions
# Event Number:
Indicates the event in sequence, where the higher the number the further distance from the OTDR the event
occurs. “E” (End) which is always displayed in the bottom row is the event determined to be the End of Fiber
(EOF).
P
:
Pass/Fail, if any one of the thresholds are not met for and event, the P/F column will display a red F. The
parameter that failed will also be displayed in red. If all the parameters are met, this column will display a green
P. The Pass/Fail threshold for the last event labeled "E" is the loss displayed in the 2POINT column, the link
loss threshold.
Km or KF or MI:
Event Location, Km for Kilometer or KF if unit of measure is Kilo-feet MI for mile. This is the distance/location
that the event occurs along the fiber link.
Splice:
Event Loss, is the splice loss (event loss) of the numbered event. (A positive number is the amount of loss and
a negative number indicates a gain normally due to mismatched index of refraction.) This is a settable threshold
for the Pass/Fail feature. The "E" event will display LINK as this is not an event that would have meaning. The
event that is deemed the EOF will normally display a large loss as this loss will be greater than the threshold
set to determine the end of the fiber.
2POINT:
2 Point Loss is the loss measured from the end of the dead zone of the previous event to the beginning of
current event. The value in the "E" line of the table for this column is the link loss. The loss from the beginning
of the trace to the event determined to be the EOF. This is the value used to determine if the fiber link passes
or fails it's loss threshold.
dB/Km:
dB per Kilometer if in KM and DB/KF if in Kilo-Feet and DB/MI if in mile unit of measure. This is the
calculated loss per Km, Kf or Mi from the end of the dead zone of the previous event to the beginning of the
current event. The value in the "E" line of the table for this column is the dB Per/KM, Kf or Mi for the total link.
TYPE:
Event Type is the type of event or the ORL measurement. If the event has no reflection, “splc” will be displayed
and if the event contains a reflection, the event reflectance value will be displayed. For the last event which is
labeled "E" in the # column, the value displayed is the system ORL.
