Motorola SG 2000 operation manual SG2 Dfbt Optical Transmitter, SG2-DFBT features

5 - 1 6 O p e r a t i o n

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

SG2000
Transmitter
LASER	O	F	SG2-DFBT
	N	A
CURRENT		U	ASSEM BLED
(1 V/A)		L	IN MEXICO
		T

Table 5-5 provides information on the user-related features of the SG2-DFBT:

Table 5-5

SG2-DFBT features

FeatureDescription

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.

SG 2000 Installation and O peration Manual