AD1000 User’s Manual
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10 Use OTDR test FTTx-PON network optical
fiber link
For FTTx-PON network optical fiber link, it’s different from normal optical fiber link,
there is branching unit in link. So, it need to know and note follow items when use
this instrument test FTTx-PON network.
10.1 Use PON optimized OTDR instrument
Some models optimized specific to FTTx-PON network optical fiber link and can get
fairly ideal result.
In order to get ideal result, it need to correctly set distance range, end threshold
(optical fiber end detecting threshold), reflection threshold ( reflection detecting
threshold) and etc.
10.2 Select the proper distance range
As there is branching unit in FTTx-PON network optical fiber link, there will be a big
attenuation event of tens dB, auto test may get a wrong distance. Suggest manually
select the parameters like proper distance range, pulse width and etc accord to the
prescient optical fiber link length.
10.3 End Threshold (optical fiber end detecting
threshold)
As there is branching unit in FTTx-PON network optical fiber link, there will be a big
attenuation event of tens dB, if the end threshold configuration is not proper, end
event may be analyzed inaccurate.
For normal optical fiber link, end threshold configuration can be 3.0dB, as to PON
network optical fiber link with branching unit, it need to set the end threshold to a
proper value and then AD1000 can locate the end event correctly. Please refer to
follow end threshold configuration sheet.
10.4 Test parameter recommendation value
Splitter type
Loss
reference
End threshold
configuration
Recommend test
pulsewidth
