14
T1/E1 FIBEROPTIC LINE DRIVER
3.4.5 O
PTICAL
S
IGNALING
In the event of a received optical signal loss, the Line Driver sends an all “ones”
signal (AIS) at a nominal frequency of 50 ppm. When the optical signalling switch
(item 5 in
Figure 3-1
) is OFF, the AIS signal is only sent to the electrical interface
of the local unit. When the switch is set to ON, an AIS optical signal is also sent to
the remote unit via the transmit optical link.
3.4.6 E
LECTRICAL
/C
HASSIS
G
ROUNDING
This jumper (item 6 in
Figure 3-1
) disconnects (NC) or connects the chassis
ground to electrical ground.
WARNING
Setting the jumper to disconnect may render the Line Driver unsafe for
connection to unprotected E1/T1 networks in some locations where
permanent excessive voltages are present on the lines.
Table 3-1. Range Switch Position.
Switch
Fiber Type
Power coupled into fiber and maximum
Position
transmission distance
850 nm
1300 nm
dBm
km*
dBm
km*
SHORT
9/125
-
-
-
-
(for 850 nm
50/125
-33
1.5
-
-
version only)
62.5/125
-29
2.2
-
-
100/140
-25
2.8
-
-
9/125
-
-
-27
16.0
LONG
50/125
-23
5.0
-20
19.0
62.5/125
-19
5.0
-16
16.0
100/140
-15
5.0
-12
14.0
*Based on commercially available fiberoptic cables.
