Motorola Starline SG 2000 - SG2-DFBT Optical Transmitter; Figure 5-18 SG2-DFBT; Table 5-5 SG2-DFBT Features

5-16 Operation
SG 2000 Installation and Operation Manual
Feature Description
Transmitter enable
A green LED that provides visual indication of the transmitter’s
enable status.
Fault indicator
A single red LED that lights when the hybrid current is outside the
normal operating range, the laser output power is below normal
limits, or the laser current is above normal limits. Because the laser
output requires a short period of time to stabilize, it is acceptable
for the fault indicator to illuminate during the stabilization interval
(approximately 2 seconds). Note that the module must be enabled
for the fault indicator to function.
SG2-DFBT Optical Transmitter
The SG2-DFBT is an isolated distributed feedback (DFB) return path optical transmitter used in the
SG 2000 node platform. It has a nominal optical output power of 1.0 mW and is used in conjunction
with an AM-RPR, AM-OMNI-RPR/2, or other similar return-path optical receiver.
Figure 5-18 illustrates the SG2-DFBT:
Figure 5-18
SG2-DFBT
F
A
U
L
T
O
N
LASER
CURRENT
(1 V/A)
OPTICAL
POWER
(1 V/mW)
SG2000
Optical Transmitter
ASSEMBLED
IN MEX ICO
SG2-DFBT
Table 5-5 provides information on the user-related features of the SG2-DFBT:
Table 5-5
SG2-DFBT features
Feature Description
Optical power test point
This test point enables monitoring of the optical output level of the
module. The nominal scale factor is 1.0 V/mW. The optical power
test-point voltage is between 0.945 V through 1.055 V (optical
power of 0.945 mW through 1.055 mW) when the module is
enabled under normal operating conditions. Note that the optical
power test point does not track changes in optical power due to the
laser tracking error.
Laser current test point
This test point enables monitoring of the current drawn by the laser
diode. The nominal scale factor is 1.0 V/A. The laser current test
point voltage is between 5 mV through 110 mV (laser current of
5 mA through 110 mA) when the module is enabled under normal
operating conditions. The laser current is expected to vary widely
with changes in temperature, but should always remain between
the limits.