Motorola SG2-DRT-3X User Manual

STARLINE®

SG2-DRT-3X
Installation Sheet 522120-001

This Installation Sheet describes the procedure for installing the SG2-DRT-3X in the SG2440 or
SG2000 node.

®

The Motorola
42 MHz analog RF return-path signals into one digital optical signal within the SG2000 and
SG2440 nodes. This digital optical signal, with 10-bit resolution and 3.1 Gbps rate, is suitable
for optical transmission to the GX2-DRR-3X Digital Return Receiver (DRR) where the original
analog return-path signals are recreated.

The transmitter is factory-configured with either a dense wave division multiplexing (DWDM)
laser on the International Telecommunications Union (ITU) grid or a coarse wave division
multiplexing (CWDM) laser that is applicable to the required link. Motorola provides standard
models that are identified in the subsection SG2-DRT-3X Models at the end of this document.
The specific wavelengths are stamped on the label of each transmitter.

Digital Return Transmitter (SG2-DRT-3X) converts three independent 5 to

An automatic power control (APC) system regulates the optical output power from the laser.
The unit provides automatic gain control (AGC) and requires no adjustment. The SG2-DRT-3X
features alarm LEDs to report local status information.

To facilitate easy upgrades, the SG2-DRT-3X has the same set-up levels as the analog return
transmitters. The double-wide module occupies the same locations as the two analog
transmitters in the node lid. The SG2-DRT-3X generates its own 5 V power and works with a
single SG2-PS2 or SG2-PS power supply.

Related Documentation

In addition to this Installation Sheet, the SG2440 Telecommunications Optical Node
Installation and Operation Manual and the SG2000 Telecommunications Optical Node
Installation and Operation Manual are required to install the SG2-DRT-3X. If you do not have

these documents, you can obtain them from the Motorola Web site.

Document Conventions

Before you begin using this Installation Sheet, familiarize yourself with the stylistic conventions
used in this document:

SMALL CAPS

*

(asterisk)

Denotes silk-screening on the equipment, typically representing input/output (I/O) and power
supply connections

Indicates that several versions of the same model number exist and the information applies to all
models; when the information applies to a specific model, the complete model number is given

Before You Begin

Before you install the SG2-DRT-3X, verify that you have received the SG2-DRT-3X-CH*Kit,
part number 498284-*.

SG2-DRT-3X Installation Sheet

2 STARLINE

Figure 1 illustrates a block diagram of the SG2-DRT-3X.

Figure 1
SG2-DRT-3X block diagram

5-42 MHz

5-42 MHz

5-42 MHz

42 MHz

LPF

42 MHz

LPF

42 MHz

LPF

LF pilot

generator

Pin

attenuator

LF pilot

generator

Pin

attenuator

LF pilot

generator

Pin

attenuator

Gain
block

Gain
block

Gain
block

RF

detector

RF

detector

RF

detector

A/D

converter

A/D

converter

A/D

converter

Filter and

clock driver

plexer

Figure 2 illustrates a top view of the SG2-DRT-3X.

Figure 2
SG2-DRT-3X transmitter

32:1

multi-

Frame

synchronization

Laser

driver

3.1 GHz

xoscillator

Microprocessor

ADC in DAC out

ITU laser

1324

F

OPTICAL

POWER

(1 V/mW)

5

A
U

Digital Return Optical Transmitter

LTO

N

ALARM

SG2-DRT-3X

I
N
P
U
T

AB

XXXXXX-XXX-XX

ITU/CH XX WAV XXXX.XX

XXXXXXXXXXX

I
N
P
U
T

SG2-DRT-3X Installation Sheet

STARLINE 3

Table 1 provides information on the user-related features of the SG2-DRT-3X.

Key Feature Description

1

2

3

4

5

OPTICAL

POWER

(1 V/mW)

F
A
U
LTO

ALARM

I
N
P
U
T

A

I
N
P
U
T

B

This test point enables monitoring of the optical output level of the module.
The nominal scale factor is 1.0 V/mW (6.3 V equates to 8 dBm). The optical

power test point does not track changes in optical power due to the laser
tracking error.

A red (

FAULT) LED indicates that the laser output power is below normal

limits.

N

A green LED (ON) indicates the transmitter is enabled.
Because the laser output requires a short period of time to stabilize, it is
normal for neither LED to illuminate for approximately 10 seconds. The
module must be enabled for the fault indicator to function.

This MCX connector provides the SG2-DRT-3X with channel A RF input
through a cable connection to the node lid board in an SG2440 or the E-pack
in an SG2000.

This MCX connector provides the SG2-DRT-3X with channel B RF input
through a cable connection to the node lid board in an SG2440 or the E-pack
in an SG2000.

Channel C RF input is provided by direct connection of the node lid board
with the D-type connector on the bottom of the SG2-DRT-3X.

This SC/APC-type connector provides optical output from the SG2-DRT-3X.

Figure 3 illustrates a side view of the SG2-DRT-3X and indicates the laser warning label.

Figure 3
SG2-DRT-3X side view and laser warning label

DANGER

INVISI BLE LAS ER RADIATIO N WHEN OPEN

PEAK POWER 10 mW

CLASS LASER PRODUCT

I

THIS PRODUCT COMPLIES WITH 21CFR

CHAPTER 1 SUBC HAPTER J

SG2-DRT-3X Installation Sheet

4 STARLINE

Installing the SG2-DRT-3X in the SG2440 Node

The SG2440 carries each RF return path individually to the lid board and no adjustments to the
electronics package (E-pack) are necessary.

Before you install the SG2-DRT-3X in the SG2440, you must configure the node with the
SG2440 DR-3X board. In this configuration, the RF return signals from RP1 and RP3 are
combined and placed onto the D-subconnector beneath the double-wide transmitter module. The
RF return signals from RP2 are routed to the MCX connector DRT1. The RF return signals from
RP4 are routed to the MCX connector DRT2. RF cables are used to route the signal from DRT1
and DRT2 to the top of the transmitter to RF

If different combining scenarios are required, you may reconfigure the RF RP cables on the
lid board.

Figure 4 illustrates a block diagram of the SG2440-DR-3X return configuration.

Figure 4
SG2440-DR-3X return configuration

INPUT A and RF INPUT B respectively.

E-PACK LID

RP1

RP3

RP2

RP4

PLUG-IN

BOARD

D sub location

3.5 dB

3.5 dB

Figure 5 illustrates the SG2440-DR-3X return board.

Figure 5
SG2440-DR-3X return board

TX

DRT1

DRT1

(MCX)

DRT2

DRT2

(MCX)

XMTR

INPUT

C

A

B

T1

R5

R1 R2

J9

R6

R4R3

SG2-DRT-3X Installation Sheet

STARLINE 5

To install the SG2-DRT-3X in the SG2440 node:

1 If present, remove any analog transmitter that occupies the optical XMTR B or A positions,

as illustrated in Figure 6, and then install the double-wide SG2-DRT-3X.

Figure 6
SG2440 lid

TP XMTR B
Pad XMTR B

Return configuration
location

RP1
RP3
RP2
RP4

DRT1
DRT2

TP XMTR A

Pad XMTR A

TP DRT1

Pad DRT1

TP DRT2

Pad DRT2

Optical XMTR B

Optical XMTR A

2 Replace the XMTR B 15 dB pad with a 5 dB pad.

3 Install the SG2-DRT-3X board in the return configuration location on the lid board as

illustrated in Figure 5.

4 Ensure that the PIC cable is properly connected to the lid and E-pack connectors.

5 Install the two RF cables from DRT MCX 1 and DRT MCX 2 to RF INPUT A and RF INPUT B

respectively on top of the SG2-DRT-3X.

6 Confirm that the green LED (ON) located on the top panel of the SG2-DRT-3X is illuminated

to confirm enable status. A delay of approximately 10 seconds before illumination is normal.

7 Review return-path system levels:

Each input of the SG2-DRT-3X is configured to drive the laser to the recommended level of

+15 dBmV.

Use TP DRT1 and TP DRT2 (Figure 5) to monitor the levels of the segmented ports. Pad

DRT1 and pad DRT2 are used to adjust the level into the transmitter.

Use TP XMTR B to monitor the levels of the two combined ports. Pad XMTR B is used to

adjust the level into the transmitter.

SG2-DRT-3X Installation Sheet