ATX ChromaFlex DMT24, ChromaFlex DMT34, ChromaFlex DMT44 Hardware Interface Manual

ChromaFlex

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength
DWDM Direct Modulated Transmitter Module

HARDWARE INTERFACE MANUAL

www.atxnetworks.com

www.atxnetworks.com

Although every effort has been taken to ensure the accuracy of this document it may be necessary, without notice, to make amendments or correct omissions.

Specications subject to change without notice.

Products or features contained herein may be covered by one or more U.S. or foreign patents. DOCSIS® and other non-ATX product and company names in this manual are the property of their
respective companies.

TABLE OF CONTENTS

1 IMPORTANT SAFETY INSTRUCTIONS .................................... 1-1

1.1 Electric Shock Hazard ............................................. 1-1

1.2 Installation Site ................................................... 1-1

1.3 Installation Requirements ........................................... 1-1

1.4 Equipment Placement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.5 Power Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

1.5.1 Connection To AC Power Source .................................... 1-2

1.5.2 Connection To -48 VDC Power Source ................................ 1-2

1.6 Fuse Replacement ................................................ 1-2

1.7 Laser Safety ..................................................... 1-2

1.8 Laser Power & Warning Labels ...................................... 1-3

2 PRODUCT INTRODUCTION ............................................. 2-1

3 UNPACKING & INSPECTING A NEW UNIT ................................. 3-1

3.1 What To Do About Physical Damage .................................. 3-1

3.2 What To Do About Concealed Damage ................................ 3-1

3.3 How To Return Equipment .......................................... 3-1

4 SPECIFICATIONS ...................................................... 4-1

5 BLOCK DIAGRAM & OPERATION ........................................ 5-1

6 FRONT PANEL ........................................................ 6-1

6.1 Front Panel Illustration ............................................. 6-1

6.2 Table of Front Panel Features ....................................... 6-1

6.3 Alarm Status Indicators ............................................. 6-1

7 MODULE INSTALLATION ............................................... 7-1

8 MODULE CONNECTIONS ............................................... 8-1

8.1 RF Connections .................................................. 8-1

8.2 Optical Connections ............................................... 8-2

9 MODULE SET-UP ...................................................... 9-1

9.1 Setting RF Input Levels ............................................ 9-1

9.1.1 All QAM Channels ................................................ 9-1

9.1.2 Mix of Analog & QAM Channels ..................................... 9-1

9.2 Conguring The DMTx4 Transmitter Module ............................ 9-1

9.2.1 AGC Mode (Hand-held Display) ...................................... 9-2

9.2.2 MGC Mode (Hand-held Display) ...................................... 9-3

9.3 Setting Transmitter Fiber Length ..................................... 9-4

10 TROUBLESHOOTING THE DMTX4 ....................................... 10-1

11. SERVICE & SUPPORT ................................................. 11-1

11.1 Contact ATX Networks .............................................11-1

11.2 Warranty Information ..............................................11-1

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iv ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

IMPORTANT SAFETY INSTRUCTIONS

1. Important Safety Instructions

• Carefully read all safety and operating instructions contained in this user guide before operating this equipment, and
retain them for future reference.

• Follow all installation and operating instructions. Pay attention to all warnings and cautions in the manual as well as

those that are af xed to this equipment.

1.1 Electric Shock Hazard

This equipment meets applicable safety standards.

WARNING: To reduce risk of electric shock, perform only the instructions that are included in the

operating instructions. Refer all servicing to qualifi ed service personnel only.

Adhere to the following safety warnings and guidelines:

• Dangerous Voltages

◦ Only quali ed service personnel are allowed to perform equipment installation or replacement.

◦ Disconnect power before servicing the unit.

◦ Only quali ed service personnel are allowed to remove chassis covers and access only  eld replaceable

pluggable accessories.

• Grounding

◦ Do not violate the protective grounding by using extension cables, power cables, or other devices on

the mains power without a protective ground conductor.

◦ If this equipment is equipped with an external grounding terminal, attach one end of an 18-gauge

wire (or larger) to the grounding terminal; then, attach the other end of the wire to a ground, such as a
grounded equipment rack.

CHAPTER 1:

IMPORTANT SAFETY INSTRUCTIONS

1.2 Installation Site

When selecting the installation site, comply with the following:

• Maintain a Protective Ground - The protective ground lead of the building’s electrical installation should comply with
national and local electrical and safety requirements.

• Environmental Condition - The installation site should be dry, clean, and ventilated. Do not use this equipment where
it could be at risk of contact with water. Ensure that this equipment is operated in an environment that meets the

requirements as stated in this equipment’s environmental speci cations.

1.3 Installation Requirements

WARNING: Allow only qualifi ed service personnel to install this equipment. The installation must

conform to all local codes and regulations.

1.4 Equipment Placement

WARNING: Avoid personal injury and damage to this equipment. An unstable mounting surface
may cause this equipment to fall.

• Install this equipment in a restricted access location.

• Place this equipment close enough to a mains AC outlet to accommodate the length of this equipment’s power cord.

• Route all power cords so that people cannot walk on, place objects on, or lean objects against them.

• Make sure the mounting surface or rack is stable and can support the size and weight of this equipment.

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 1-1

CHAPTER 1:

IMPORTANT SAFETY INSTRUCTIONS

• Make sure that the rack is placed on a stable surface. If the rack has stabilizing devices, install these stabilizing
devices before mounting any equipment in the rack. The mounting surface or rack should be appropriately anchored

according to manufacturer’s speci cations.

• Ensure this equipment is securely fastened to the mounting surface or rack to protect against damage.

• This equipment has openings for ventilation to protect it from overheating. To ensure equipment reliability and safe
operation, do not block or cover any of the ventilation openings.

WARNING: Avoid personal injury and damage to this equipment. Mounting this equipment in the
rack should be such that a hazardous condition is not caused due to uneven mechanical loading.

CAUTION: Installation of this equipment in a rack should be such that the amount of airfl ow

required for safe operation of this equipment is not compromised.

1.5 Power Connections

1.5.1 Connection To AC Power Source

Important: If this equipment is a Class I equipment, it must be grounded.

• Connect this equipment only to the power sources that are identi ed on the equipment-rating label.

• Overcurrent protection breakers or fuses must be sized appropriately for the total current rating of the modules and
accessories contained within a system chassis or multiple chassis that are connected to a common mains circuit.

• This equipment may have two power sources. Be sure to disconnect all power sources before working on this
equipment.

• If this equipment does not have a main power switch, the power cord connector serves as the disconnect device.

1.5.2 Connection To -48 VDC Power Source

• Use at least #16 AWG wire for all DC power wiring.

• Overcurrent protection breakers or fuses must be sized appropriately for the total current rating of the modules and
accessories contained within a system chassis.

• Follow the recommended practices of the DC power system manufacturer.

CAUTION: Consider the connection of this equipment to the supply circuit and the effect that
overloading of circuits might have on overcurrent protection and supply wiring.

1.6 Fuse Replacement

To replace a fuse, comply with the following:

• Disconnect the power before changing fuses.

• Identify and clear the condition that caused the original fuse failure.

• Always use a fuse of the correct type and rating. The correct type and rating are indicated on this equipment.

1.7 Laser Safety

This equipment may contain or be connected to an infrared laser source that transmits intensity-modulated light and emits
invisible radiation.

1-2 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

WARNING: Avoid Personal Injury. The laser light source on this equipment or the fi ber cables

connected to this equipment emit invisible laser radiation. Avoid direct exposure to the laser light
source.

Viewing the laser output (if a transmitter) or fi ber cable with optical instruments may pose an eye

hazard.

This equipment may only be installed, operated and serviced by authorized personnel trained in

the safe handling and operation of fi ber optic cables and laser sources.

• Do not apply power to this equipment if the  ber is unmated or unterminated.

• Do not look into an activated  ber with optical instruments such as magni ers, or microscopes.

1.8 Laser Power & Warning Labels

This equipment may contain or be connected to other equipment containing Class 1M laser sources. The following labels
adhered to each product will indicate the type of laser source utilized along with general laser radiation labels.

CHAPTER 1:

IMPORTANT SAFETY INSTRUCTIONS

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 1-3

IMPORTANT SAFETY INSTRUCTIONS

CHAPTER 2:

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1-4 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

PRODUCT INTRODUCTION

2. Product Introduction

These are directly modulated C-Band DWDM downstream transmitter modules supporting up to 1.2 GHz for full DOCSIS®

3.1 spectrum. LC/APC front ber launch with or without internal multiplexing of outputs. Also includes front female F-port test
point with selection switch to locally monitor any individual laser input.

DMT24 has two separate lasers with one common RF input port (broadcast) and one unique (narrowcast) port per laser. For
a total of three RF inputs at rear of chassis.

DMT34 has three separate lasers with one common RF input port (broadcast) and one unique (narrowcast) port per laser.
For a total of four RF inputs at rear of chassis.

DMT44 has four separate lasers with one unique (narrowcast) port per laser. For a total of four RF inputs at rear of chassis.
Any Broadcast/Narrowcast combining is done externally if needed.

CHAPTER 2:

PRODUCT INTRODUCTION

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PRODUCT INTRODUCTION

CHAPTER 2:

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2-2 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

UNPACKING & INSPECTING A NEW UNIT

3. Unpacking & Inspecting a New Unit

Before shipment, ATX inspects and packs all the essential items carefully. Nevertheless, damage may occur during
shipment. The carrier assumes full responsibility for a safe delivery of the equipment.

Inspect the package for any physical damage.

1. Open the package.

2. Remove any packing material.

3. Inspect the unit for any physical damage.

4. Shake the unit with care, paying attention to any rattling loose parts that may suggest a concealed damage (some
noise due to moving cables is normal).

5. Check for any missing accessories.

When any damage is noticed to the merchandise, please notify customer service (see Service & Support section) and le a
claim with the carrier as noted below.

3.1 What To Do About Physical Damage

Record any evidence of physical damage or loss on the freight bill or receipt and have the carrier’s agent sign it. If you fail

to do so, the carrier may refuse to honor the damage claim. The carrier will supply you with any forms required to le such a

claim.

CHAPTER 3:

UNPACKING & INSPECTING A NEW UNIT

3.2 What To Do About Concealed Damage

Damage which is not apparent until the unit has been unpacked is considered concealed damage. The contents may have
been damaged due to rough handling even if there is no external evidence. If you should notice damage upon unpacking the
unit you should make a written request for inspection by the carrier’s agent within 10 days of the delivery date. Afterwards

le a claim with the carrier.

3.3 How To Return Equipment

Call customer service (see Service & Support section) for a Return Materials Authorization (RMA) number. You will need the
unit’s serial number, description of the problem, and some shipping information. We must receive the unit within thirty (30)
days from the date a RMA number is issued. If for any reason, you want to ship the unit 30 days after the RMA number has
been issued, you must obtain a new RMA number by calling customer service. Units received without an RMA number or
one with an expired RMA number will not be accepted by our receiving department.

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 3-1

CHAPTER 3:

UNPACKING & INSPECTING A NEW UNIT

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3-2 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

SPECIFICATIONS

4. Specications

See ChromaFlex DMT24, DMT34 & DMT44 DWDM Transmitter Specs & Ordering Info pdf at atxnetworks.com

CHAPTER 4:

SPECIFICATIONS

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CHAPTER 4:

SPECIFICATIONS

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4-2 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

BLOCK DIAGRAM & OPERATION

5. Block Diagram & Operation

The following block diagrams depict the RF and optical signal ow through the DMT24, DMT34 and DMT44 transmitter

modules:

BC

Input

(*-4)

Splitter

CHAPTER 5:

Front Panel

Test Point - 10 dB

BLOCK DIAGRAM & OPERATION

NC1
(*-1)

NC2
(*-2)

* = card

number (1..8)

Figure 1: ChromaFlex DMT24 Transmitter Module Block Diagram

BC

Input

(*-4)

NC1
(*-1)

NC2
(*-2)

Splitter

Variable

Attenuator

Variable

Attenuator

Variable

Attenuator

Variable

Attenuator

RF Det.

ITU*

Opt. Mux

RF Det.

ITU*

OUT 1

OUT 2

DMT24

Front Panel

Test Point - 10 dB

RF Det.

RF Det.

ITU*

ITU*

Opt. Mux

OUT 1

OUT 2

NC3
(*-3)

* = card

number (1..8)

Variable

Attenuator

RF Det.

ITU*

OUT 3

DMT34

Figure 2: ChromaFlex DMT34 Transmitter Module Block Diagram

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 5-1

CHAPTER 5:

BLOCK DIAGRAM & OPERATION

Input 1

(*-1)

Input 2

(*-2)

Input 3

(*-3)

Input 4

(*-4)

* = card

number (1..8)

Figure 3: ChromaFlex DMT44 Transmitter Module Block Diagram

As seen in the block diagrams above and as described in Product Introduction, the DMT24 and DMT34 have internal RF
combining to merge a common broadcast RF input signal to each individual NC input. The DMT44 has no such combining
since all four rear F-ports are utilized for direct application to each laser segment in the quad module. After this initial
combining stage, all transmitter versions have the same functionality.

Front Panel

Test Point - 10 dB

Variable

Attenuator

RF Det.

Variable

Attenuator

RF Det.

Variable

Attenuator

RF Det.

Variable

Attenuator

RF Det.

ITU*

ITU*

ITU*

ITU*

Opt. Mux

DMT44

OUT 1

OUT 2

OUT 3

OUT 4

A directional coupler for each laser segment provides a sample of the full spectrum RF load applied to each laser to the
switchable female F-port on the front. This level is calibrated to be -10 dB relative to the input at the rear of the module,
regardless of AGC function of the module. The RF signal passes through a variable RF attenuator. The attenuator is
either automatically set through the feedback loop when operated in the AGC mode or may be set in the manual mode via

software interfaces. The signal is amplied and then passes through a directional coupler used to sample the RF signal for

remote monitoring and the AGC control loop back to the input variable attenuator. The through path is applied to a laser.

Fiber length adjustment for the laser is set through the software interfaces. The optical signal passes to each of the front

panel optical connectors. An internal multiplexer option is available in which case each wavelength is multiplexed internally
with the combined wavelengths connected to output port 1.

5-2 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

FRONT PANEL

6. Front Panel

6.1 Front Panel Illustration

The following diagram and table depicts the features of the transmitter module front panel. The DMT44 module is shown for
reference. The DMT24 and DMT34 are labeled “NA” or “N” for the unused optical connector and RF test point selection.

CHAPTER 6:

FRONT PANEL

6.2 Table of Front Panel Features

Module Extraction Levers Lever assist in removing the module from the chassis backplane

Module Retaining Screws Secures the module to the chassis.

Module Handle Utilized to insert and remove the module.

RF Test Point -10 dB sample of the RF input to the module. Relative to RF input at

RF Test Point Selector Switch Selects the RF test point for transmitter 1 to 4.

Optical Output LC/APC Connector (OUT) Optical output signal connection.

Transmitter Alarm LEDs Visual alarm status indicators for each of the four transmitters.

6.3 Alarm Status Indicators

LED Function Value

OPT One LED for Each Laser 1 through 4

Optical Output Power

Laser Temperature

Module Temperature

Figure 4: Front Panel

connector.

rear of module.

Green = Normal

Amber = Minor Temp Alarm or Opt
Power +/- 1dB

Red = Major Temp Alarm or Opt

Power +/- 2 dB

RF One LED for Each Laser 1 through 4

Monitors the RF Drive Level to Each
Laser

For more information regarding alarm status and monitoring refer to the ChromaFlex Operation Manual.

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 6-1

Green = Normal

Amber = Minor Alarm, RF Out of
Range +/- 2 dB

Red = Major Alarm, RF Out of

Range +/- 3 dB

CHAPTER 6:

FRONT PANEL

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6-2 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

MODULE INSTALLATION

7. Module Installation

The DMTx4 (x=2, 3 or 4) transmitter module occupies a single ChromaFlex chassis module slot. The modules may be
inserted or removed while the chassis is powered without interrupting other operational modules in the chassis. The
following module installation procedures assume the chassis is installed and powered following the instructions in the
ChromaFlex Operation Manual.

1. Align the module into the desired slot opening in the ChromaFlex chassis.

2. Using the handle push the module into the slot with even pressure until the module is mated with the chassis mid­plane connector.

3. Press the module extraction levers downward against the module face.

4. Tighten the two module retaining screws until snug in an even manner.

5. The module LEDs should now be lit with the four OPT LEDs green and the four RF LEDs red (DMT44) if RF has not
already been connected to the chassis rear panel RF connectors.

CHAPTER 7:

MODULE INSTALLATION

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 7-1

CHAPTER 7:

MODULE INSTALLATION

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7-2 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

MODULE CONNECTIONS

8. Module Connections

The following describes the initial RF and optical connections to the chassis and module.

8.1 RF Connections

RF connections are made at the back of the ChromaFlex chassis. The DMT24 and DMT34 have one broadcast input
which is shared across each laser transmitter and two or three narrowcast inputs for the dedicated services to each laser
transmitter. The DMT44 has a single RF input for each laser transmitter where the common broadcast and each individual
laser transmitter narrowcast channels is externally combined prior to connection to the chassis.

NOTE: Each laser transmitter should have the same common RF channel content below 270 MHz.

CHAPTER 8:

MODULE CONNECTIONS

Figure 5: RF Connections

The following table and diagrams show the corresponding RF connector to module slots for the DMTx4 transmitter modules.
The RF connector numbering corresponds to the chassis slot number – laser transmitter number. For example, RF
connector 1-1 is connected to chassis slot 1- laser transmitter 1 within the module. RF connector 1-2 is connected to chassis
slot 1- laser transmitter 2 within the module.

Figure 6: DMT24 – Rear Panel RF Connections

Figure 7: DMT34 – Rear Panel RF Connections

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 8-1

1-1 Narrowcast 1 Narrowcast 1 RF 1
1-2 Narrowcast 2 Narrowcast 2 RF 2
1-3 N/A Narrowcast 3 RF 3
1-4 Broadcast Broadcast RF 4
2-1 Narrowcast 1 Narrowcast 1 RF 1
2-2 Narrowcast 2 Narrowcast 2 RF 2
2-3 N/A Narrowcast 3 RF 3
2-4 Broadcast Broadcast RF 4
3-1 Narrowcast 1 Narrowcast 1 RF 1
3-2 Narrowcast 2 Narrowcast 2 RF 2
3-3 N/A Narrowcast 3 RF 3
3-4 Broadcast Broadcast RF 4
4-1 Narrowcast 1 Narrowcast 1 RF 1
4-2 Narrowcast 2 Narrowcast 2 RF 2
4-3 N/A Narrowcast 3 RF 3
4-4 Broadcast Broadcast RF 4
5-1 Narrowcast 1 Narrowcast 1 RF 1
5-2 Narrowcast 2 Narrowcast 2 RF 2
5-3 N/A Narrowcast 3 RF 3
5-4 Broadcast Broadcast RF 4
6-1 Narrowcast 1 Narrowcast 1 RF 1
6-2 Narrowcast 2 Narrowcast 2 RF 2
6-3 N/A Narrowcast 3 RF 3
6-4 Broadcast Broadcast RF 4
7-1 Narrowcast 1 Narrowcast 1 RF 1
7-2 Narrowcast 2 Narrowcast 2 RF 2
7-3 N/A Narrowcast 3 RF 3
7-4 Broadcast Broadcast RF 4
8-1 Narrowcast 1 Narrowcast 1 RF 1
8-2 Narrowcast 2 Narrowcast 2 RF 2
8-3 N/A Narrowcast 3 RF 3

8
DMT34

DMT44

(BC & NC external combine)

3

4

5

6

7

Modul e

Slot

Rear Panel
Connector

DMT24

1

2

CHAPTER 8:

MODULE CONNECTIONS

Figure 8: DMT44 – Rear Panel RF Connections

8.2 Optical Connections

8-2 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

There are many different optical system congurations that are possible with the ChromaFlex DMTx4 transmitter.

The transmitter may have individual output ports per laser transmitter or they can be optioned with an internal optical

multiplexer with all wavelengths combined to a single optical output on port number 1. Your specic design may include

additional components such as external multiplexers, an EDFA, return path receivers, destacker modules or other external
components.

CHAPTER 8:

MODULE CONNECTIONS

Important Note: Always clean and inspect optical connectors prior to making a connection to the

DMTx4 optical ports. Never look into an optical connector when a signal is present.

Figure 9: Optical Connections

Please take the following steps for  rst time set up of the unit.

• Identify the transmitter unit at the corresponding slot location.

• Connect each output port (1 through 4) to a  ber jumper utilizing a good quality clean LC/APC connector to the next

device or  ber cable per your speci c design schematic drawing.

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 8-3

CHAPTER 8:

MODULE CONNECTIONS

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8-4 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

MODULE SET-UP

9. Module Set-up

9.1 Setting RF Input Levels

The RF signals that are common to each laser transmitter are connected to the Broadcast (BC) input port as shown in the
rear panel connector table in section 6.1. The common RF loading into the BC RF input port should occupy the RF spectrum
to at least approximately 270 MHz to avoid SRS crosstalk degradation.

The Narrowcast (NC) signals for each of the individual laser transmitters is connected to the corresponding input port
as shown in the rear panel connector table in section 6.1. Note that the NC input should be all QAM signals and above
270 MHz. The RF combining is performed externally for the DMT44 module with four laser transmitters. Follow the same
guidelines for combining BC and NC RF signals as described above.

Determining the proper rear panel RF input level is important to ensure optimum transmitter performance. The following will

provide guidance in calculating the proper adjustment to the per channel RF level for your actual channel loading from the

reference channel loading and the total RF input power requirement.

Each DMTx4 transmitter is factory optimized for a rear panel nominaltotal input power of +31 dBmV for the combined BC
and NC signals. This level provides 3 to 4 dB of reserve gain for the AGC operation. The reserve gain is the amount of
headroom below the +31 dBmV reference level.

CHAPTER 9:

MODULE SET-UP

9.1.1 All QAM Channels

The all QAM reference channel loading and per channel input level is 155 ITU-T J.83 Annex B QAM 256 channels between
54-1002 MHz set to 9 dBmV. The RF per channel level of 9 dBmV is calculated from the total power as follows:

Total Power - [10*log

31 dBmV - [10*log

(channel load)]

10

(155)] = 31 dBmV – 22 = 9 dBmV

10

Using the same formula to adjust for a lower channel loading such as a 750 MHz system with 110 channels:

31 dBmV - [10*log

(110)] = 31 dBmV – 20.4 = 10.6 dBmV

10

Therefore with 110 of all QAM channel loading the correct rear panel RF input level is 10.6 dBmV at the input of both the BC
and NC ports.

9.1.2 Mix of Analog & QAM Channels

The mix of Analog and QAM reference channel loading and per channel input level is 30 NTSC analog (54-258 MHz) set to
13 dBmV and 124 ITU-T J.83 Annex B QAM 256 channels (258-1002 MHz) set to 11 dBmV. The RF level per channel for
analog and QAM is calculated from the total power as follows:

Since there is a 6 dB power level difference between the QAM and analog channels it is easier if we convert the QAM
channels to an equivalent analog power level in the formula below. The QAM RF level being 6 dB lower means the QAM
power level is 1/4

Total Power - [10*log

31 dBmV - [10*log

Therefore the analog channels are set to 13 dBmV and the QAM channels are 6 dB lower or 11 dBmV.

Use the same formula to increase the number of analog channels to 60 and decrease the number of QAM channels to 94
and calculate the correct input level for each:

31 dBmV - [10*log

Therefore the analog channels are set to 12 dBmV and the QAM channels 6 dB lower or 6 dBmV.

th

the analog level. As a point of reference, -3 dB is 1/2 power and -6 dB is 1/4 power.

(Analog channel load)+(QAM channel load/4)]

10

((30)+(124/4))] = 31 dBmV – 18 = 13 dBmV

10

((60)+(94/4))] = 31 dBmV – 19 = 12 dBmV

10

9.2 Conguring The DMTx4 Transmitter Module

To set-up, congure and verify the RF drive level for the DMTx4 requires the operator to become familiar with the Hand­held Display or GUI status and conguration menus. Refer to the ChromaFlex Chassis – Hardware Interface Manual as a

supplement to the following procedures which will reference the associated display parameters.

The following DMTx4 Hand-held Display menu tree will assist in navigating the Hand-held Display.

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 9-1

Greeting:

InnoTrans Communications
DMTX

Power(dBm)
RF Lvl(dB)
Tx Attn (dB)
Temp(C)
Lambda(nm)
Prev Menu

Setup

Mode
Settings

Sel_Ch
Mode
Save
Prev Menu

Gain
Settings

Sel_Ch
RF Lvl(rdB)
Gain(Steps)
Save
Prev Menu

Alarm

Laser Temperature
Laser Pwr
RF Level
Unit Temp
Prev Menu

Status

Chassis

Temperature(C)
Model
Hardware Version
Software Version
Serial Number
Prev Menu

Tx Fiber
Length

Sel_Ch
Length (km)
Save
Prev Menu

Prev Menu

CHAPTER 9:

MODULE SET-UP

9.2.1 AGC Mode (Hand-held Display)

Operating in the AGC mode provides for plug-and-play RF level setting as the transmitter automatically sets the internal
attenuators for the optimal laser drive level and OMI. When in the AGC mode the variable attenuators will automatically

be adjusted for each laser transmitter so the RF reference display will read 0.0 dB ± 0.5 dB. The following provides the
procedures and associated menus for conguring the DMTx4 with the Hand-held Display in the AGC mode.

1. Connect power to the chassis. Unit should power up (no switches).

2. Plug the RS-232 cable from the Hand-held Display into the RS-232 port on the CF-CTLR control and communications
module.

3. Using the Hand-held Display choose the appropriate slot for the desired module location.

4. Example DMT34 - With a combined Broadcast/Narrowcast total RF power of 31 dBmV plug the Broadcast cable into

9-2 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

port 1-4, Narrowcast cable into port 1-1 to 1-3. (see section 6.1)

RF : -0.1

Att(dB): +3.5

S etup Menu

Tx Status Menu

M od e Setting Menu

Gain S etting Me nu

M ode: MGC

Save : No ( AGC)

S ave: Yes (MGC)

Prev Menu

G ain Setting Menu

OPTOut Setting Menu

Rf Lv l (rd B): -1.0

Gain(steps): 4.5

Rf Lv l (rdB): -0.1

Gain(steps): -3.5

Gain(steps): -3.5

S ave: Yes (-3.5)

Tx Status Menu

Alar m Men u

5. From the front panel RF Test Point conrm the Narrowcast QAM RF channels are at the same level as the Broadcast
QAM RF channels. If not, correct the level difference coming into the chassis on each individual NC port.

6. Using the Hand-held Display navigate to the Tx Setup Menu.

7. Under the Tx Status menu the RF (reference level) reading should be approximately 0.0 dB, ± 0.5 dB. The Att (dB)
(reserve gain level) should be between 3-4 dB (if 31 dBmV total RF power is applied to input ports).

The reserve gain is the amount of headroom below the +31 dBmV reference level.

9.2.2 MGC Mode (Hand-held Display)

The following provides the procedures and associated menus for conguring the DMTx4 with the Hand-held Display in the
MGC mode. When operating in the MGC mode the variable attenuator for each laser transmitter can be manually adjusted
to so the RF reference display will read 0.0 dB ± 0.5 dB.

1. Connect power to the chassis. Unit should power up (no switches).

2. Plug the RS-232 cable from the Hand-held Display into the RS-232 port on the CF-CTLR control and communications
module.

3. Using the Hand-held Display choose the appropriate slot for the desired module location.

4. Example DMT34 - With a combined Broadcast/Narrowcast total RF power of 31 dBmV plug the Broadcast cable into
port 1-4, Narrowcast cable into port 1-1 to 1-3. (see section 8.1)

5. From the front panel RF Test Point conrm the Narrowcast QAM RF channels are at the same level as the Broadcast
QAM RF channels. If not, correct the level difference coming into the chassis on each individual NC port.

6. Using the Hand-held Display navigate to the Setup/Mode Settings menu.

CHAPTER 9:

MODULE SET-UP

7. Under the Setup/Mode Settings menu place the unit in MGC mode and save the setting.

8. Next using the Hand-held Display navigate to the Setup/Gain Settings menu.

9. Select the internal laser transmitter to be adjusted (Sel_Ch)

10. Under the Gain Setting Menu note the RF Lvl.

11. Using the Gain (Steps) menu add or remove the attenuation steps until the RF Lvl displays 0.0 dB - ± 0.5 dB in the
Tx Status/RF menu.

12. Save Gain (Steps) value.

13. Next using the Hand-held Display navigate to the Tx Status menu.

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 9-3

14. Under the Tx Status Menu note the RF level. The level should be the same value as the RF Lvl value set in step #10.

The Att (dB) value should be +3.5 ± 0.5 dB with a total combined input power of 31 dBmV at the back of the chassis.

RF : -0.1

Att(dB): +3.5

S etup Menu

Tx Status Menu

M ode Setting Menu

Tx Fiber Length:

CHAPTER 9:

MODULE SET-UP

15. Repeat the RF adjustment steps for each laser transmitter.

9.3 Setting Transmitter Fiber Length

The ber link length that each laser transmitter will propagate through needs to be entered to achieve optimal distortion

performance.

1. Using the Hand-held Display navigate to the Setup/Mode Settings/TX Fiber Length menu.

2. Select the internal laser transmitter to be adjusted (Sel_Ch).

3. Enter the ber length in km associated with the selected laser transmitter. This should not be based on distance

measured on a map. Use an optical TDR for proper ber length.

4. Repeat for each laser transmitter.

9-4 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

TROUBLESHOOTING THE DMTX4

10. Troubleshooting The DMTx4

Condition Steps to Check

Power LED OFF (AC) Check if Power Cable is plugged in and Power Switch is in ON position.

Verify AC Outlet is Functional and conrm fuse on the AC feed is ne, replacing it if

necessary.

Look for other signs of life in unit like running fan, LCD display etc.

Power LED OFF (DC) Verify DC Feed is active and fuse is intact on fuse panel.

Verify DC Feed is not reversed.

Look for other signs of life in unit like running fan, LCD display etc.

Optical LED is Amber or Red Check output light level.

RF LED is Amber or Red Check RF Input level.

If in MGC mode Attn set too high (or too low if overdriving RF inputs).

Communication Issue with Unit Please conrm set-up is as described in the User Interface document.

If problem persists, please contact customer service for further help.

CHAPTER 10:

TROUBLESHOOTING THE DMTX4

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 10-1

CHAPTER 10:

TROUBLESHOOTING THE DMTX4

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10-2 ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual

SERVICE & SUPPORT

11. Service & Support

11.1 Contact ATX Networks

Please contact ATX Technical Support for assistance with any ATX products.

TECHNICAL SUPPORT

Tel: [phone] – press 4
Fax: [phone]
Email: [email protected]

CUSTOMER SERVICE

ATX Networks
5850 Hellyer Avenue
San Jose, CA 95138 USA

Tel: [phone] – press 3
Fax: [phone]
Email: [email protected]
Web: www.atxnetworks.com

CHAPTER 11:

SERVICE & SUPPORT

11.2 Warranty Information

All of ATX Networks’ products have a 1-year warranty that covers manufacturer’s defects or failures.

ChromaFlex DMT24, DMT34 & DMT44 Multi-Wavelength DWDM Direct Modulated Transmitter Module – Hardware Interface Manual 11-1

ISO

REGISTERED

9001:15

© 2018 ATX Networks
Information in this document is subject to change without notice.

Rev. 09/18 (ANW1169)

ATX Networks

1-501 Clements Road West, Ajax, ON L1S 7H4 Canada

Tel: [phone] | Toll Free: 800.565.7488 | [email protected]

www.atxnetworks.com