2.4
Cannectian distance
The maximum ttbre-optic cable length between two tibre-optic
adaptore, dopende on
• tranamitter‘s output
•
receivers sensitivity
• tibre-optic cable attenuation.
lt the transmission power ot the tibre-optic adaptor is too email, the
signal will not ha received CIearly. lt the transmission power is tOo
high, the signal will be overdriven.
The cable attenuation depende on
• tibre-optic cable quality
• tibre-optic cable Iength
• wave length.
The wave length used 5 b6Onm.
The tibre-optic Cable quality ix detined in deeibel per kIlometer
(dB/km) and detcrmined by the cable used.
Some tibre-optic adaptore have changeable transmission powers
(minimum and maximum), and theretore they can ha used tor two
ditterent cable lengths.
In the tollowing, the possible cable lengtha are aasigned to the
transmission powers ot Ihe single adaptore tors cable attenuation
ot 150dB/km:
Fibre-optio adaptor
and cable
lenglh tor 150dB/km
Unit
changeover
awitoh
Transmission power cable angSt
2121
yes
min
max
min
0 -4cm
max
30-65m
2122
ne
min
mix
0 -4cm
3133
ne
max
max
30-SSm
2124
yes
min
max
min
0
-4cm
max
30-SSm
2125
ne
min
0 -40m
2128
xc
mao
30 - 85 m
With unpoliahed tibre-optic cable ends, the maximum Cable length
is typically reduced by 13 m.
They are typically reduced by 2 m at every arc (30 mm radius>.
Note:
The tibre-optic cable may not be ahorter than the minimum
lengthl
Lanze
11
