Lanex MD-76, Руководство по эксплуатации

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E1/G.703 F
IBER
O
PTIC
M
ODEM
O
PERATING
M
ANUAL
IOA76-1F 18 May 2009
Table 9. Power balance
Device version
76.1-3-1 76.1-3-1 76.1-3-2 76.1-4-1 76.1-5/6-1 76.1-5/6-2
1
Wave length
(
for WDM have been done
calculation for unfavourable
case - 1310 nm
)
LASER
1310
nm SH
LASER
1310 nm
SH
LASER
1310 nm
LH
LASER
550 nm
SH
WDM
1310/1550
nm SH
WDM
1310/155
0 nm LH
2 Type of optical fiber
1310 nm 1310 nm 1310 nm 1550 nm 1310 nm 1310 nm
3 Transmitter power level
SM
MM
1)
SM SM SM SM
4 Receiver sensitivity
[dBm] -15 -15 -5 -5 -14 -8
5 Power budget (3-4)
[dBm] -35 -35 -36 -35 -34 -34
6 Power margin for devices
[dBm] 20 20 31 30 20 26
7 Power margin for cable
[dB] 4 4 4 4 4 4
8
Light pipe attenuation
coefficient
[dB] 2 2 3 3 2 3
9
Through-connector average
attenuation
[dB/k
m] 0,4 1 0,4 0,2 0,4 0,4
10
Transmission range
(5-6-7)/(8+9)
[dB] 0,1 0,2 0,1 0,1 0,1 0,1
11 Minimum line attenuation
[km] 28 12 48 77 28 38
[dB] 0 dB 0 dB 0 dB 0 dB 0 dB 0 dB
1)
The device can operate with multimode optical fibers .
TM-76 and MD-76 modems can operate with a two-fiber optical line based - depending on
version - on:
•
50/125 or 62.5/125
µ
m multimode optical fibers - with SC connector;
•
single-mode optical fibers - with SC/PC connectors (angle terminal connectors must not be
used - their symbol usually includes APC marking).
A connection should be made with a double station cable or two single cables. The device
should be positioned in such a manner that no forces - lateral or longitudinal - act on
the connectors. A cable bend radius cannot be less than a value recommended by
the manufacturer - it can be practically assumed as 50 mm.
Optical fiber connectors - particularly single-mode ones - are very precise components.
That is why they should be handled with care, with no excessive forces when connecting
and disconnecting them. Also the socket and the plug "ferrule" should be kept ideally clean.
If dirty, the socket can be blown with clean compressed air, while the ferrule can be cleaned with
isopropyl or ethyl alcohol (denatured alcohol must not be used). A piece of cloth, which does not
leave fibers, should be used for this purpose.
The diameter of the single-mode optical fiber core is only 9
µ
m. Thus any contamination
particles of similar size may cause significant signal attenuation and completely disable
transmission.
If no optical fiber plugs are connected to the device, the sockets should be always secured
with protective caps to avoid dust penetration.