Motorola SG 2000 用户手册
3 - 1 0
B e n c h S e t u p
S G 2 0 0 0 I n s t a l l a t i o n a n d O p e r a t i o n M a n u a l
Analog Return Path
Figure 3-1 illustrates the location of the return-path transmitter modules.
To set up analog return-path transmitters:
1
Confirm the transmitter configuration required. For a single transmitter, use the optical
transmitter A position. The redundant transmitter uses the optical transmitter B position.
Redundancy options are discussed in Section 5, “Operation.”
transmitter A position. The redundant transmitter uses the optical transmitter B position.
Redundancy options are discussed in Section 5, “Operation.”
2
For each return-path transmitter, measure the optical power level at the test point provided on the
top panel of the transmitter as illustrated in Figure 5-12. The scaled voltage present at this test
point is 1.0 V/mW.
top panel of the transmitter as illustrated in Figure 5-12. The scaled voltage present at this test
point is 1.0 V/mW.
3
Verify that the green LED (
ON
), located on the top panel of the transmitter, is illuminated to
confirm enable status. Refer to Section 5, “Operation,” for
FAULT
LED functions.
4
Review return-path system levels. The unit is configured to drive the laser to the recommended
level (+15 dBmV) when the total combined power at all ports is approximately +28 dBmV.
level (+15 dBmV) when the total combined power at all ports is approximately +28 dBmV.
Digital Return Path
To set up digital return-path transmitters:
1
Confirm the transmitter configuration required. For a single transmitter, use the optical
transmitter A position. The redundant transmitter uses the optical transmitter B position.
Redundancy options are discussed in Section 5, “Operation.”
transmitter A position. The redundant transmitter uses the optical transmitter B position.
Redundancy options are discussed in Section 5, “Operation.”
2
Verify that the green LED (
ON
), located on the top panel of the transmitter, is illuminated. Refer
to Section 5, “Operation,” for
FAULT
LED functions.
3
Review return-path system levels. The unit is configured to drive the laser to the recommended
level (+15 dBmV) when the total combined power at all ports is approximately +28 dBmV.
level (+15 dBmV) when the total combined power at all ports is approximately +28 dBmV.
Two models of return path modules are available with analog and digital transmitters:
T
With the SG 2000 return path module/combined (SG2-RPM/C), the total combined power at
all four ports totals approximately +28 dBmV.
all four ports totals approximately +28 dBmV.
T
With the SG 2000 return path module/split (SG2-RPM/S), the total combined power at each
pair of ports is approximately +28 dBmV.
pair of ports is approximately +28 dBmV.
For more specific information regarding return path setup procedures, refer to the supplemental
document Return Path Level Selection, Setup, and Alignment Procedure.
document Return Path Level Selection, Setup, and Alignment Procedure.