Motorola SG 2000 用户手册
5 - 1 8 O p e r a t i o n
SG 20 00 Ins tal la tion and O pera tion M anua l
SG2-DF BT /3 Optical Transmitte r
The SG2-DFBT/3 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 2.0 mW and is used in
conjunction with an AM-RPR, AM-OMNI-RPR/2, or other similar return-path optical receiver.
the SG 2000 node platform. It has a nominal optical output power of 2.0 mW and is used in
conjunction with an AM-RPR, AM-OMNI-RPR/2, or other similar return-path optical receiver.
Figure 5-19 illustrates the SG2-DFBT/3:
F i g u r e 5 - 1 9
S G 2 - D F B T / 3
S G 2 - D F B T / 3
F
A
U
L
T
A
U
L
T
O
N
N
LASER
CURRENT
(1 V/A)
OPTICAL
POWER
(1 V/mW)
SG2000
Optical Transmitter
ASSEM BLED
IN MEXICO
SG2-DFBT/3
Table 5-6 provides information on the user-related features of the SG2-DFBT/3:
T a b l e 5 - 6
SG 2 - D F B T / 3 f e a t u r e s
SG 2 - D F B T / 3 f e a t u r e s
Feature Desc ription
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.
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.
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.
Transmitter enable
A green LED that provides visual indication of the transmitter’s
enable status.
enable status.
Fault indicator
A single red LED that lights if 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.
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.