EXFO OTDR 2 - Manual (Page 205)

Description of Event Types
OTDR 197
Merged Event
All Event Types Are Tested
In the first case, where all event types are tested, the pass/fail conditions
are as follows:

If the event loss is less than or equal to the smallest threshold value,
then the event status is Pass.

If the event loss is greater than the sum of the number of sub-events of
a type, multiplied by the threshold value for this event type, then the
event status is Fail.

If the event loss is “in between”, since it is not possible to know exactly
the weight of a sub-event in the merged event, the global event is
considered to have a status of Pass.
If the merged event loss is smaller than or equal to 1.2, then the status is
Pass. Otherwise, it is Fail.
Pass/Fail Analysis Fail Level
=

(N
sub
x Th
sub
)
= (2 x 0.5) + (1 x 0.2)
= 1.2
Pass
Pass
Fail
0
0.2
1.2