Table of Contents
Advertisement
380
Optical fibre communication module
Optical
fibres
REx5xx
)LJXUH 0XOWLSOH[HG OLQN ILEUH RSWLFDOJDOYDQLF FRQQHFWLRQ ZLWK )2;3OXV
'HVLJQ
The optical communication module is designed to work with both 9/125 µ m single-
mode fibres and 50/125 or 62,5/125 µ m multimode fibres at 1300 nm wavelength. The
connectors are of type FC-PC (SM) or FC (MM) respectively. Two different levels of
optical output power are used. The level of optical power is selected with a setting. Low
power is used at short fibers in order not to saturate the receiver and thereby jeopardiz-
ing the functionality, and high power is used for long fibers to handle the high attenua-
tion that follow. The optical budget of the modem, at high output power, is 16dB for
single mode fiber and 21dB for multi mode fiber. This means that the total loss in the
fiber has to be less than the optical budget. The losses in the connection to the protection
terminal are not to be included in the optical budget since they are already accounted
for. The maximum reach will depend on the properties of the used optical fiber but be
around 20 km for multi mode fibers and about 30 km for single mode during normal
conditions.
Example: The attenuation in the fibres is normally approximately 0.8 dB/km for multi-
mode and 0.4 dB/km for single-mode. Additional attenuation due to installation can be
estimated to be 0.2dB/km for multimode and 0.1 dB/km for single-mode fibres. For sin-
gle-mode fibre and high output power this results in a maximum distance of 32km. With
lower attenuation, a longer distance can be achieved.
Galvanic
G.703
FOX 6
Plus
<10 m
other
users
'DWD FRPPXQLFDWLRQ
to the
MUX
other end
xx00000535.vsd
&KDSWHU
Advertisement
Table of Contents
