SETTING TRACE OPTIONS
To see an additional menu of trace options, press
from the trace
screen until the following menu options appear:
opens the TRACE OPTIONS menu
selects the next or previous trace option
changes the value in the selected trace option
CAPTURE MODE – Range of values: AUTO, SEMI, USER, FILT, LIVE
Capture Mode should be set to
AUTO
mode for a majority of testing
scenarios, so the OTDR can automatically determine the best set of trace
parameters based on the fiber link under test.
USER,
SEMI,
FILT, and LIVE
require the user to understand
the consequences of setting trace parameters manually.
Only trained fiber optic professionals who are experienced with operating OTDRs should manually set trace parameters.
Suggestions for setting these parameters are given below.
PULSE WIDTH – range of values: Multimode: 1, 2, 5, 10, 20, 50, 100 m; Singlemode: 1, 2, 5, 10, 20, 50, 100, 200, 500, 1000 m.
Pulse width should be set to the shortest setting that allows multiple closely-spaced events to be clearly defined, while preventing any
of the trace from reaching the noise floor.
NUMBER OF SAMPLES – Range of values: 256, 512, 1024, 2048, 4096.
Use the maximum number of samples unless traces are
taking to long to acquire.
DEAD ZONE LENGTH (m) – Range of values: 0 to 1500.
Set this value to ‘0000’ if not using a dead-zone box (a.k.a. pulse
suppressor box). If using a dead-zone box, and you want to highlight the dead-zone box length on the trace, enter the length of the
dead-zone box in meters.
RANGE – range of values: 1, 2, 5, 10, 25, 50, 65, 128 km.
Set to the next highest value from the actual length of the fiber under test.
If fiber length is unknown, select MAX km.
STEP – Range of values: 1, 2, 4 m.
Use shortest STEP value for most accurate distance to events, unless trace acquisition time is
too long.
SETUP
9
SECTION 2: OTDR TESTING
SETTING TEST PARAMETERS, cont.
SETUP
INDEX
LOAD
SAVE
TRACE OPTIONS
CAPTURE MODE
PULSE WIDTH
NUMBER OF
SAMPLES
DEAD ZONE
LENGTH(m)
RANGE
STEP
SAVE
QUIT
HELP
AUTO
1m
4096
1100
MAXkm
1m