Remote PHY 220 | GS7000 4-Port 1GHZ Node | GS7000 4-Port 1218MHz Intelligent Node | Model GS7000 4-Port Node 1 GHz | Remote PHY 120 | User guide | Cisco 1.2GHz GS7000 Node Installation and Operation Guide
Cisco 1.2 GHz GS7000 Node
Installation and Operation Guide
For Your Safety
Explanation of Warning and Caution Icons
Avoid personal injury and product damage! Do not proceed beyond any symbol until you fully understand the indicated conditions.
The following warning and caution icons alert you to important information about the safe operation of this product:
You may find this symbol in the document that accompanies this product.
This symbol indicates important operating or maintenance instructions.
You may find this symbol affixed to the product. This symbol indicates a live terminal where a dangerous voltage may be present; the tip of the flash points
to the terminal device.
You may find this symbol affixed to the product. This symbol indicates a
protective ground terminal.
You may find this symbol affixed to the product. This symbol indicates a
chassis terminal (normally used for equipotential bonding).
You may find this symbol affixed to the product. This symbol warns of a
potentially hot surface.
You may find this symbol affixed to the product and in this document. This symbol indicates an infrared laser that transmits intensity-modulated light and emits invisible laser radiation or an LED that transmits
intensity-modulated light.
Important
Please read this entire guide. If this guide provides installation or operation instructions, give particular attention to all safety statements included in this guide.
Notices
Trademark Acknowledgments
Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this
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Third party trademarks mentioned are the property of their respective owners.
The use of the word partner does not imply a partnership relationship between
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Cisco Systems, Inc. assumes no responsibility for errors or omissions that may appear in this publication. We reserve the right to change this publication at any time without notice. This document is not to be construed as conferring by implication, estoppel, or otherwise any license or right under any copyright or patent, whether or not the use of any information in this document employs an invention claimed in any existing or later issued patent.
Copyright
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Contents
General Information 1
Theory of Operation 15
Installation 65
Setup and Operation 89
iii
Contents
Maintenance 121
Troubleshooting 139
No RF Output: Fiber Optic Light Level is Good, Receiver Optical Power LED is on 142
Customer Support Information 151
Appendix A Technical Information 153
Appendix B Enhanced Digital Return Multiplexing Applications 158
Appendix C Expanded Fiber Tray 197
iv
Glossary
Index
Contents
213
225
v
Important Safety Instructions
Important Safety Instructions
Read and Retain Instructions
Carefully read all safety and operating instructions before operating this equipment, and retain them for future reference.
Follow Instructions and Heed Warnings
Follow all operating and use instructions. Pay attention to all warnings and cautions in the operating instructions, as well as those that are affixed to this equipment.
Terminology
The terms defined below are used in this document. The definitions given are based on those found in safety standards.
Service Personnel - The term service personnel applies to trained and qualified individuals who are allowed to install, replace, or service electrical equipment. The service personnel are expected to use their experience and technical skills to avoid possible injury to themselves and others due to hazards that exist in service and restricted access areas.
User and Operator - The terms user and operator apply to persons other than service personnel.
Ground(ing) and Earth(ing) - The terms ground(ing) and earth(ing) are synonymous.
This document uses ground(ing) for clarity, but it can be interpreted as having the same meaning as earth(ing).
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 qualified service
personnel only.
Electric shock can cause personal injury or even death. Avoid direct contact with dangerous voltages at all times.
Know the following safety warnings and guidelines:
Only qualified service personnel are allowed to perform equipment installation vii
Important Safety Instructions
or replacement.
Only qualified service personnel are allowed to remove chassis covers and access any of the components inside the chassis.
Equipment Placement
WARNING:
Avoid personal injury and damage to this equipment. An unstable mounting
surface may cause this equipment to fall.
To protect against equipment damage or injury to personnel, comply with the following:
Install this equipment in a restricted access location (access restricted to service personnel).
Make sure the mounting surface or rack is stable and can support the size and weight of this equipment.
Strand (Aerial) Installation
CAUTION:
Be aware of the size and weight of strand-mounted equipment during the
installation operation.
Ensure that the strand can safely support the equipment’s weight. viii
Pedestal, Service Closet, Equipment Room or Underground Vault
Installation
WARNING:
Avoid the possibility of personal injury. Ensure proper handling/lifting techniques are employed when working in confined spaces with heavy
equipment.
Ensure this equipment is securely fastened to the mounting surface or rack where necessary to protect against damage due to any disturbance and subsequent fall.
Ensure the mounting surface or rack is appropriately anchored according to manufacturer’s specifications.
Ensure the installation site meets the ventilation requirements given in the equipment’s data sheet to avoid the possibility of equipment overheating.
Ensure the installation site and operating environment is compatible with the equipment’s International Protection (IP) rating specified in the equipment’s data sheet.
Important Safety Instructions
Connection to Network Power Sources
Refer to this equipment’s specific installation instructions in this manual or in companion manuals in this series for connection to network ferro-resonant AC power sources.
AC Power Shunts
AC power shunts may be provided with this equipment.
Important: The power shunts (where provided) must be removed before installing modules into a powered housing. With the shunts removed, power surge to the components and RF-connectors is reduced.
CAUTION:
RF connectors and housing seizure assemblies can be damaged if shunts are not removed from the equipment before installing or removing modules from
the housing.
Equipotential Bonding
If this equipment is equipped with an external chassis terminal marked with the IEC
60417-5020 chassis icon ( ), the installer should refer to CENELEC standard EN
50083-1 or IEC standard IEC 60728-11 for correct equipotential bonding connection instructions.
General Servicing Precautions
WARNING:
Avoid electric shock! Opening or removing this equipment’s cover may
expose you to dangerous voltages.
CAUTION:
These servicing precautions are for the guidance of qualified service personnel only. To reduce the risk of electric shock, do not perform any servicing other than that contained in the operating instructions unless you
are qualified to do so. Refer all servicing to qualified service personnel.
Be aware of the following general precautions and guidelines:
Servicing - Servicing is required when this equipment has been damaged in any way, such as power supply cord or plug is damaged, liquid has been spilled or objects have fallen into this equipment, this equipment has been exposed to rain or moisture, does not operate normally, or has been dropped. ix
Important Safety Instructions
Wristwatch and Jewelry - For personal safety and to avoid damage of this equipment during service and repair, do not wear electrically conducting objects such as a wristwatch or jewelry.
Lightning - Do not work on this equipment, or connect or disconnect cables, during periods of lightning.
Labels - Do not remove any warning labels. Replace damaged or illegible warning labels with new ones.
Covers - Do not open the cover of this equipment and attempt service unless instructed to do so in the instructions. Refer all servicing to qualified service personnel only.
Moisture - Do not allow moisture to enter this equipment.
Cleaning - Use a damp cloth for cleaning.
Safety Checks - After service, assemble this equipment and perform safety checks to ensure it is safe to use before putting it back into operation.
Electrostatic Discharge
Electrostatic discharge (ESD) results from the static electricity buildup on the human body and other objects. This static discharge can degrade components and cause failures.
Take the following precautions against electrostatic discharge:
Use an anti-static bench mat and a wrist strap or ankle strap designed to safely ground ESD potentials through a resistive element.
Keep components in their anti-static packaging until installed.
Avoid touching electronic components when installing a module.
Batteries
This product may contain batteries. Special instructions apply regarding the safe use and disposal of batteries:
Safety
Insert batteries correctly. There may be a risk of explosion if the batteries are incorrectly inserted.
Do not attempt to recharge ‘disposable’ or ‘non-reusable’ batteries.
Please follow instructions provided for charging ‘rechargeable’ batteries.
Replace batteries with the same or equivalent type recommended by manufacturer. x
Important Safety Instructions
Do not expose batteries to temperatures above 100°C (212°F).
Disposal
The batteries may contain substances that could be harmful to the environment
Recycle or dispose of batteries in accordance with the battery manufacturer’s instructions and local/national disposal and recycling regulations.
The batteries may contain perchlorate, a known hazardous substance, so special handling and disposal of this product might be necessary. For more information about perchlorate and best management practices for perchlorate-containing substance, see www.dtsc.ca.gov/hazardouswaste/perchlorate.
Modifications
This equipment has been designed and tested to comply with applicable safety, laser safety, and EMC regulations, codes, and standards to ensure safe operation in its intended environment. Refer to this equipment's data sheet for details about regulatory compliance approvals.
Do not make modifications to this equipment. Any changes or modifications could void the user’s authority to operate this equipment.
Modifications have the potential to degrade the level of protection built into this equipment, putting people and property at risk of injury or damage. Those persons making any modifications expose themselves to the penalties arising from proven non-compliance with regulatory requirements and to civil litigation for compensation in respect of consequential damages or injury.
Accessories
Use only attachments or accessories specified by the manufacturer.
Electromagnetic Compatibility Regulatory Requirements
This equipment meets applicable electromagnetic compatibility (EMC) regulatory requirements. Refer to this equipment's data sheet for details about regulatory compliance approvals. EMC performance is dependent upon the use of correctly shielded cables of good quality for all external connections, except the power source, when installing this equipment.
Ensure compliance with cable/connector specifications and associated installation instructions where given elsewhere in this manual. xi
Important Safety Instructions
EMC Compliance Statements
Where this equipment is subject to USA FCC and/or Industry Canada rules, the following statements apply:
FCC Statement for Class A Equipment
This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when this equipment is operated in a commercial environment.
This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case users will be required to correct the interference at their own expense.
Industry Canada - Industrie Canadiene Statement
This apparatus complies with Canadian ICES-003.
Cet appareil est confome à la norme NMB-003 du Canada.
CENELEC/CISPR Statement with Respect to Class A Information Technology Equipment
This is a Class A equipment. In a domestic environment this equipment may cause radio interference in which case the user may be required to take adequate measures. xii
Laser Safety
Laser Safety
Introduction
This equipment contains an infrared laser that transmits intensity-modulated light and emits invisible radiation.
Warning: Radiation
WARNING:
Avoid personal injury! Use of controls, adjustments, or procedures other
than those specified herein may result in hazardous radiation exposure.
Avoid personal injury! The laser light source on this equipment (if a transmitter) or the fiber cables connected to this equipment emit invisible
laser radiation. Avoid direct exposure to the laser light source.
Avoid personal injury! Viewing the laser output (if a transmitter) or fiber cable with optical instruments (such as eye loupes, magnifiers, or
microscopes) may pose an eye hazard.
Do not apply power to this equipment if the fiber is unmated or unterminated.
Do not stare into an unmated fiber or at any mirror-like surface that could reflect light emitted from an unterminated fiber.
Do not view an activated fiber with optical instruments (e.g., eye loupes, magnifiers, microscopes).
Use safety-approved optical fiber cable to maintain compliance with applicable laser safety requirements.
Warning: Fiber Optic Cables
WARNING:
Avoid personal injury! Qualified service personnel may only perform the procedures in this manual. Wear safety glasses and use extreme caution when handling fiber optic cables, particularly during splicing or terminating operations. The thin glass fiber core at the center of the cable is fragile when exposed by the removal of cladding and buffer material. It easily fragments into glass splinters. Using tweezers, place splinters immediately in a sealed waste container and dispose of them safely in accordance with local
regulations. xiii
Laser Safety
Safe Operation for Software Controlling Optical Transmission
Equipment
If this manual discusses software, the software described is used to monitor and/or control ours and other vendors’ electrical and optical equipment designed to transmit video, voice, or data signals. Certain safety precautions must be observed when operating equipment of this nature.
For equipment specific safety requirements, refer to the appropriate section of the equipment documentation.
For safe operation of this software, refer to the following warnings.
WARNING:
Ensure that all optical connections are complete or terminated before using this equipment to remotely control a laser device. An optical or laser device can pose a hazard to remotely located personnel when operated
without their knowledge.
Allow only personnel trained in laser safety to operate this software.
Otherwise, injuries to personnel may occur.
Restrict access of this software to authorized personnel only.
Install this software in equipment that is located in a restricted access area. xiv
Laser Warning Labels
Laser Warning Labels
Maximum Laser Power
The maximum laser power that can be expected from the EDFA optical amplifier for various amplifier configurations is defined in the following table.
Output
Power
17 dBm
20 dBm
22 dBm
Maximum
Output
17 dBm
20 dBm
22 dBm
CDRH
Classification
1
1
1
IEC 60825-1
Classification
1M
1M
1M
IEC 60825-2
Hazard Level
1M
1M
3B
Warning Labels
One or more of the labels shown below are located on this product. xv
Laser Warning Labels
Location of Labels on Equipment
The following illustrations display the location of warning labels on this equipment. xvi
Laser Warning Labels
xvii
1
Chapter 1
General Information
Introduction
This manual describes the installation and operation of the 1.2 GHz
GS7000 Node.
In This Chapter
Equipment Description .......................................................................... 2
1
Chapter 1 General Information
Equipment Description
Overview
This section contains a physical and functional description of the 1.2 GHz GS7000
Node.
Physical Description
The 1.2 GHz GS7000 Node is the latest generation 1.2 GHz optical node platform which uses the housing developed for the GS7000 Node Platform, but it has been painted for improved thermal performance. The housing has a hinged lid to allow access to the internal electrical and optical components. The housing also has provisions for strand, pedestal, or wall mounting.
Note: The 1.2 GHz GS7000 node is painted white, and the pictures in this document which use unpainted housings are used as references.
The base of the housing contains:
an RF amplifier module
AC power routing
forward and reverse configuration modules (configuration will vary)
The lid of the housing contains:
a fiber management tray and track (included in all nodes)
optical receiver and transmitter modules (configuration will vary)
EDFA (erbium-doped fiber amplifier) modules and optical switch modules
(for hub node application)
power supplies (one or two)
a status monitor/local control module (optional)
Not every 1.2 GHz GS7000 Node contains all of these modules. The 1.2 GHz GS7000
Node is a versatile node that can be configured to meet various network requirements.
2
Equipment Description
The following illustration shows the external housing of the 1.2 GHz GS7000 Node.
3
Chapter 1 General Information
The following illustration shows the 1.2 GHz GS7000 Node internal modules and components.
4
Functional Description
Node
The 1.2 GHz GS7000 Node is used in broadband hybrid fiber/coax (HFC) networks.
It is configured with the receivers, transmitters, configuration modules, and other modules to meet your unique network requirements. This platform allows independent segmentation and redundancy for both the forward and reverse paths in a reliable, cost-effective package.
Equipment Description
The 1.2 GHz GS7000 Node receives forward optical inputs, converts the input to an electrical radio frequency (RF) signal, and outputs the RF signals at up to six ports.
The forward bandwidth is from 54 MHz (or 86, 102, 258 MHz) to 1218 MHz. The lower edge of the passband is primarily determined by the diplex filter and the reverse amplifier assembly. Diplex filter choices are 54 MHz, 86 MHz, 102 MHz, and
258 MHz.
The forward path of the 1.2 GHz GS7000 Node can be deployed with a broadcast
1310/1550 nm optical receiver with common services distributed to either four output ports (all high level) or six output ports (two high level and four lower level).
The forward path can also be segmented by using one optical receiver that feeds all output ports, two independent optical receivers that each feed half of the node’s output ports (left/right segmentation) or four independent optical receivers that feed four independent forward paths. Forward optical path redundancy is supported via the use of optional local control module. The type of forward segmentation and/or redundancy is determined by the type of RF amplifier assembly and Forward Configuration Module installed in the node.
The 1.2 GHz GS7000 Node’s reverse path is equally flexible. Reverse traffic can be segmented or combined and routed to up to four DFB reverse optical transmitters, or up to four Enhanced Digital Return reverse optical transmitters as part of our EDR system. Redundant (back-up) transmitters may be utilized. In addition, an auxiliary input path is provided for reverse signal injection (5 - 210 MHz). Reverse segmentation and/or redundancy are determined by the type of Reverse
Configuration Module installed in the node.
The 1.2 GHz GS7000 Node accepts Optical Transmitter Modules based on the existing 694x/GainMaker optical transmitters. Reverse optical transmitters can be installed to transmit data, video, or both. Reverse bandwidth is determined by the diplex filter and the reverse amplifier assembly. Diplex filter choices are 42/54 MHz,
65/86 MHz, 85/102 MHz, and 204/258 MHz.
The 1.2 GHz GS7000 Node utilizes the transmitter and receiver module covers that have been designed to allow fiber pigtails storage within them, providing improved fiber management within the node.
Up to four optical receivers and up to four analog or two digital transmitters can be installed in the 1.2 GHz GS7000 Node.
45 - 90 V AC input power is converted to +24.5, +8.5, -6.0, and +5.5 V DC by an internal power supply to power the 1.2 GHz GS7000 Node.
Hub Node
The GS7000 Hub Node performs the same functions as the GS7000 Node with the added benefit of also providing optical gain and optical switching capability. The hub node allows you to push fiber deeper into your network while taking advantage
5
Chapter 1 General Information
of the RF plant that is already in place.
The GS7000 Node can be upgraded to a GS7000 Hub Node in the field. This is accomplished by the installation of optical amplification (EDFA) modules, optical switching modules, and the Status Monitor/Local Control Module in the node lid.
The GS7000 Hub Node can then serve as a traditional node feeding the local HFC plant and as an optical hub with the optical amplifiers. The node hub with the amplifiers can service up to 32 nodes at a distance of 50 km with only three fibers.
EDFAs are available in 17 dBm, 20 dBm, and 22 dBm for broadcast constant output power. A 17 dBm, 20 dBm and 21 dBm narrowcast constant gain EDFA version is available to fit any architecture for requirements like DWDM narrowcasting.
The optical switch module is used for switching the input of an EDFA module from a primary signal to a backup or secondary signal. The switch is monitored and controlled by the Status Monitor/Local Control Module (SM/LCM) in the node.
A specific model of the SM/LCM is required for use in the hub node. This SM/LCM model monitors and controls several EDFA and optical switch parameters and functions while continuing to monitor the standard node components.
6
Features
The 1.2 GHz GS7000 Node has the following features:
Six port 1.2 GHz RF platform
Uses rugged GaN Technology on the output stage
Uses standard GainMaker style accessories (i.e., attenuator pads, equalizers, diplexers and crowbar)
Field accessible plug-in Forward Interstage Linear Equalizers,
Forward/Reverse Configuration Modules, and Node Signal Directors
3-state reverse switch (on/off/-6 dB) allows each reverse input to be isolated for noise and ingress troubleshooting (status monitor or local control module required)
Auxiliary reverse injection (5 - 210 MHz) configurable on up to 2 ports (port 3 or port 6)
Positions for up to 4 optical receivers and 4 optical transmitters in housing lid
Provides hub node functionality with addition of available optical amplifier and optical switch modules
Optional low-cost Local Control Module may be installed in conjunction with a Redundant Forward Configuration Module to allow optical forward path
Equipment Description
redundancy when no status monitor is present
Fiber entry ports on both ends of housing lid
Fiber management tray and track provides easy access to fiber connections
Primary and redundant power supplies with passive load sharing
Spring loaded seizure assemblies allow coax connectors to be installed or removed without removing amplifier chassis or spring loaded mechanism from the rear of the housing base
Dual/Split AC powering
Space provided for mounting WDM modules inside the housing lid.
Node Inputs/Outputs Diagram
The following diagram shows the system-level inputs and outputs of the 1.2 GHz
GS7000 Node.
The AC can be applied to any RF port and routed, if required, to the other ports.
The DC power supply modules can be fed by any RF port (1 through 6).
Modules Functional Descriptions
This table briefly describes each module. The 1.2 GHz GS7000 Node may not contain
all these modules. See Theory of Operation (on page 15) for detailed descriptions of
the modules.
7
Chapter 1 General Information
Module
RF Amplifier
Forward
Configuration
Description
The RF Amplifier Module includes:
four separate and independent forward amplification paths, each having one or two RF outputs.
four independent reverse inputs.
forward and reverse bandwidths that are established by diplexer and reverse amplifier assembly selection.
There are several types of this module.
The 1x4 Forward Configuration Module (FCM) is used when the 1.2
GHz GS7000 Node is configured with a single optical receiver routed to all four outputs of the amplifiers. This module splits the signals equally to the inputs of the RF amplifier module. The 1x4 Forward
Configuration Modules with forward RF injection are similar to the
1x4 Forward Configuration Modules, but are used with the Forward
Local Injection (FLI) Module. The FLI Module routes an RF signal from an external source to the Forward Configuration Module which is then coupled with other inputs from an optical receiver.
The 1x4 Redundant Forward Configuration Module is used when the
1.2 GHz GS7000 Node is configured with two optical receivers routed to all four outputs of the amplifiers in a redundant configuration.
Receiver 1 is the primary receiver and Receiver 2 is the backup. The active receiver is selected with a status monitor or local control monitor.
8
Equipment Description
Module
Forward
Configuration
(cont'd)
Description
The 1x4 Redundant Forward Configuration Modules with forward RF injection are similar to the 1x4 Redundant Forward Configuration
Modules, but are used with the Forward Local Injection (FLI) Module.
The FLI Module routes an RF signal from an external source to the
Forward Configuration Module which is then coupled with other inputs from an optical receiver.
The 2x4 Forward Configuration Module is used when the 1.2 GHz
GS7000 Node is configured with two optical receivers, each feeding two/three outputs of the amplifier module. In this configuration, the node serving area is divided in half in the forward direction. Receiver
1 is routed to RF amplifier Ports 4 and 5/6, while Receiver 3 is routed to RF amplifier Ports 1 and 2/3.
The 2x4 Redundant Forward Configuration Module is used when the
GS7000 Node is configured with four optical receivers with each pair feeding two/three RF outputs of the amplifier module in a redundant configuration. In this configuration, the node serving area is divided in half, with redundancy, in the forward direction. Receivers 1
(primary) and 2 (redundant) are routed to RF amplifier Ports 4 and
5/6, while Receivers 3 (primary) and 4 (redundant) are routed to RF amplifier Ports 1 and 2/3. The active receiver is selected with a status monitor or local control monitor.
The 3x4 Forward Configuration Module is used when the 1.2 GHz
GS7000 Node is configured with three receivers each feeding one/two/three/four outputs of the amplifier module. Two versions of this module are available. In one version Receiver 1 is routed to RF amplifier ports 4/5/6, Receiver 3 is routed to port 1, and Receiver 4 is routed to ports 2/3. In the other version Receiver 1 is routed to RF amplifier ports 5/6, Receiver 2 is routed to port 4, and Receiver 4 is routed to ports 1/2/3. (Note that the 3x4 FCM can only be used with the 4-way RF amplifier module.)
The 4x4 Forward Configuration Module is used when the 1.2 GHz
GS7000 Node is configured with four optical receivers with each feeding separate RF outputs of the amplifier module. Receiver 1 is routed to RF amplifier Ports 5/6. Receiver 2 is routed to RF amplifier
Port 4. Receiver 3 is routed to RF amplifier Port 1. Receiver 4 is routed to RF amplifier Ports 2/3. (Note that the 4x4 FCM can only be used with the 4-way RF amplifier module.)
9
Chapter 1 General Information
Module
Reverse
Configuration
Description
There are several types of this module.
The 4x1 Reverse Configuration Module (RCM) with auxiliary
reverse RF injection combines all four reverse RF inputs (Ports 1, 2/3,
4, and 5/6) of the node and routes the signal to Transmitter 1. An RF signal from an external source can optionally be injected and coupled with the reverse RF inputs on Ports 3/6 and routed to Transmitter 1.
The 4x1 Redundant Reverse Configuration Module combines all four reverse RF signals (Ports 1, 2/3, 4 and 5/6) together, splits this RF signal and routes it to Transmitters 1 and 2.
The 4x2 Reverse Configuration Module with auxiliary reverse RF
injection combines reverse inputs from Ports 1 and 2/3 and routes them to Transmitter 1; it also combines reverse inputs from Ports 4 and 5/6 and routes them to Transmitter 3. An RF signal from an external source can optionally be injected and coupled with reverse RF inputs from Ports 3/6 and routed to Transmitter 1.
The 4x2 Redundant Reverse Configuration Module combines reverse inputs from Ports 1 and 2/3 and routes them to Transmitters 1 and 2; it also combines reverse inputs from Ports 4 and 5/6 and routes them to Transmitters 3 and 4.
The 4x3 Reverse Configuration Module with auxiliary reverse RF
injection is available in two types. The left-combined/right-segmented version combines reverse inputs from
Ports 1 and 2/3 and routes them to Transmitter 1; it also routes reverse inputs from Port 4 to Transmitter 3 and from Ports 5/6 to Transmitter
4. An RF signal from an external source can optionally be injected at
Ports 3/6 and coupled with the reverse RF input from Port 1 and routed to Transmitter 1. The left-segmented/right-combined version combines reverse inputs from Ports 4 and 5/6 and routes them to
Transmitter 4; it also routes reverse inputs from Port 1 to Transmitter 1 and from Ports 2/3 to Transmitter 2. An RF signal from an external source can optionally be injected at Ports 3/6 and coupled with the reverse RF inputs from Ports 2/3 and 1 and routed to Transmitter 1.
10
Equipment Description
Module
Reverse
Configuration
(cont'd)
Description
The 4x4 Reverse Configuration Module with auxiliary reverse RF
injection routes reverse inputs from Port 1 to Transmitter 1, from Port
2/3 to Transmitter 2, from Port 4 to Transmitter 3, and from Port 5/6 to Transmitter 4. An RF signal from an external source can optionally be injected and coupled with reverse RF inputs from Ports 3/6 and routed to Transmitter 1. (Note that this module is typically installed when using EDR multiplexing digital reverse modules. Since the digital reverse module occupies the physical space that transmitters 3 and 4 normally occupy in the node base, this reverse configuration module is typically used with a 6-port optical interface board.)
Optical Receiver This module converts an optical signal from the headend into a forward path RF signal. An SC/APC fiber connector is standard.
Optical power, test points, and status LEDs are provided.
Optical
Transmitter
Optical
Amplifier
(EDFA)
Optical Switch
This module converts reverse path RF signals from the network into an optical signal. An SC/APC fiber connector is standard. Multiple transmitter options are available such as uncooled DFB, 1550 ITU, and
EDR. EDR uses the included LC/APC connector that jumps over to an
SC/APC bulkhead. Optical power, test points, and status LEDs are provided.
Erbium-doped fiber amplifier modules are available in two categories: broadcast and narrowcast (gain-flattened). EDFAs are available in 17 dBm, 20 dBm, and 22 dBm for broadcast constant output power. A 17 dBm, 20 dBm and 21 dBm narrowcast constant gain EDFA version is available to fit any architecture for requirements like DWDM narrowcasting. EDFA modules are single-wide, single-output devices.
The modules mount in receiver or transmitter slots on the optical interface board in the node lid using a reversible pin adapter. The
EDFA is monitored and controlled by the Status Monitor/Local
Control Module in the node.
The optical switch module is used for switching the input of an EDFA module from a primary signal to a backup or secondary signal. The module mounts in receiver or transmitter slots on the optical interface board in the node lid using a reversible pin adapter. The switch is monitored and controlled by the Status Monitor/Local Control
Module in the node.
11
Chapter 1 General Information
Module
Status Monitor/
Local Control
Module
(SM/LCM)
Power Supply
Description
The local control module monitors the input optical power of up to four receivers and four transmitters, plus AC power entry and power supply voltage rails. It also provides local reverse path wink and shutdown capabilities through the PC-based GS7000 ViewPort software. It can be upgraded to a status monitor which provides node monitoring and control capability at the cable plant's headend. This module is not required for normal operation of the node. In a hub node application the SM/LCM also monitors and controls the operation of the EDFAs and optical switches.
The 1.2 GHz GS7000 power supply module has multiple output voltages of +24.5, +8.5, -6.0, and +5.5 V DC. A second power supply can be installed in the node for redundancy or load sharing.
The 1.2 GHz GS7000 Node can be set up in the following powering configurations:
two power supplies powered by different AC sources
two power supplies using the same AC source
a single supply using a single AC source
The fiber management system secures and protects the optical fiber inside the node housing.
Fiber
Management
Tray and Track
Optical Interface
Board
The Optical Interface Board (OIB) provides all interconnections between the modules in the housing lid of the 1.2 GHz GS7000 Node.
Each module in the lid plugs directly into the OIB through a connector header or row of sockets. Input attenuator pads are provided on the
OIB for each optical receiver in the housing lid. Output attenuator pads are provided on the OIB for each optical transmitter in the housing lid.
12
Equipment Description
Ordering Information
The 1.2 GHz GS7000 Node is available in a wide variety of configurations. Please refer to the 1.2 GHz GS7000 Node Data Sheet for a full listing of the configured node, components, and accessories that are available.
Note: Please consult with your Account Representative, Customer Service
Representative, or System Engineer to determine the best configuration PID for your particular application.
Note: Please consult with your Account Representative, Customer Service Representative, or System Engineer to determine the best configuration for your particular application.
13
2
Chapter 2
Theory of Operation
Introduction
This chapter describes the theory of operation for the 1.2 GHz GS7000
Node, including functional descriptions of each module in the node.
The 1.2 GHz GS7000 Node is comprised of two parts, the lid and the base.
The lid houses an optical interface board (OIB), and some of the following products: one to four optical receivers, one to four optical transmitters, one digital return module with one or two digital transmitters, EDFA (optional), optical switch (optional), a status monitor (optional) or a local control module (optional), one or two power supplies, and a fiber management tray/track.
The base houses the RF amplifier module and the accessories that plug into it. These accessories include a forward configuration module, four forward band linear equalizer modules, multiple attenuator pads, two node signal director jumper or splitter modules, and two auxiliary reverse injection director modules. Also contained within the launch amplifier module are a reverse auxiliary jumper/combiner/amplifier/termination module and a reverse configuration module.
15
Chapter 2 Theory of Operation
In This Chapter
RF Amplifier Module ........................................................................... 24
Forward Configuration Module ......................................................... 29
Reverse Configuration Module .......................................................... 34
Optical Interface Board (OIB) .............................................................. 38
Optical Receiver Module ..................................................................... 39
Optical Analog Transmitter Modules ................................................ 43
Optical Amplifier (EDFA) Modules ................................................... 45
Optical Switch Module ........................................................................ 52
Local Control Module .......................................................................... 58
Power Supply Module ......................................................................... 61
16
System Diagrams
System Diagrams
External
-20 dB TP
Functional Diagrams: 4-Way Forward Segmentable Node
The following diagrams show the signal flow through the 4-way forward segmentable node.
Non-Segmented
-20 dB
Fwd. TP
RF Switch RF Switch
P1
AC
Byp ass
Power Director
FWD
REV
EQ Pad
Pad Pad
Pad EQ FWD
REV
-20 dB
Rev. TP
Pad Pad
-20 dB
Rev. TP
Thermal
External
-20 dB TP
AC
Byp ass
Power Director
P4
Thermal
External
-20 dB TP
P2
External
-20 dB TP
P3
AC
Byp ass
Power Director
-20 dB
Fwd. TP
-20 dB
Rev. TP
Node
Signal Director
Jumper
FWD
REV
EQ Pad
RF Switch
Pad
Crowbar
AC
Byp ass
Power Director
-20 dB
Fwd. TP
-20 dB
Rev. TP
Pad
Aux. Reverse Injection
Director
(to RCM)
5
-210 MHz
Reverse Injection
Option
1x4
Forward Configuration
Module
Pad
Thermal
Pad
Thermal
RF Switch
Pad EQ
RS
RS RS
Pad
RS
RS = reverse switch
Aux. Rev
RF
Injection
FWD
REV
Node
Signal Director
Splitter
-20 dB
Rev. TP
4x1 Reverse
Configuration Module w/Aux Reverse
RF Injection
(to RCM)
5
-210 MHz
Reverse Injection
Option
Pad
Aux. Reverse Injection
Director
-20 dB
Rev. TP
Crowbar
External
-20 dB TP
AC
Byp ass
Power Director
P5
External
-20 dB TP
AC
Byp ass
Power Director
P6
F1
Power
Supply #2
Power
Supply #1
Fiber Tray
Pad Pad Pad
RCVR
# 1
Pad
Optical
Interface Board
Pad
Pad
XMT R
# 1
Pad Pad Pad
P
P
TP
F2
17
Chapter 2 Theory of Operation
Left-Right Segmented
18
System Diagrams
External
-20 dB TP
Fully Segmented
-20 dB
Fwd. TP
P1
AC
Byp ass
Power Director
-20 dB
Rev. TP
FWD
REV
Pad
EQ Pad
RF Switch
External
-20 dB TP
P2
External
-20 dB TP
P3
-20 dB
Fwd. TP Node
Signal Director
Jumper
RF Switch
AC
Byp ass
Power Director
-20 dB
Rev. TP
FWD
REV
EQ Pad
Pad
Crowbar
AC
Byp ass
Power Director
-20 dB
Fwd. TP
-20 dB
Rev. TP
Pad
Aux. Reverse Injection
Director
(to RCM)
5
-210 MHz
Reverse Injection
Option
4x4
Forward Configuration
Module
Pad
Thermal
Pad Pad
Thermal
Thermal
RF Switch
Pad EQ
Pad
FWD
REV
-20 dB
Rev. TP
External
-20 dB TP
AC
Byp ass
Power Director
P4
Pad
Thermal
Aux. Rev
RF
Injection
RF Switch
Pad EQ
RS
RS RS
RS
Pad
RS = reverse switch
FWD
REV
Node
Signal Director
Splitter
-20 dB
Rev. TP
AC
Byp ass
Power Director
Ext ernal
-20 dB TP
P5
4x4 Reverse
Configuration Module w/Aux Reverse
RF Injection
(to RCM)
5
-210 MHz
Reverse Injection
Option
Pad
Aux. Reverse Injection
Director
-20 dB
Rev. TP
Crowbar
Ext ernal
-20 dB TP
AC
Byp ass
Power Director
P6
F1
Power
Supply #2
Fiber Tray
Power
Supply #1
RCVR
# 4
Pad Pad
RCVR
# 3
RCVR
# 2
Pad
RCVR
# 1
Pad
Optical
Interface Board
Pad
Pad
XMT R
# 1
Pad
XMT R
# 2
Pad
XMT R
# 3
Pad
XMT R
# 4
P P P P
P P P P
TP TP TP TP
F2
19
Chapter 2 Theory of Operation
Functional Diagram: Hub Node
The following diagram shows the signal flow through a 4-way non-segmented hub node.
20
Forward Path
Forward Path
Introduction
Forward path refers to signals received by the node from the headend. These signals are amplified in the node and routed to subscribers through the cable distribution network.
4-Way Forward Path Signal Routing
1.2 GHz GS7000 Node 4-way forward path signal routing functions are described below.
Stage
1
2
3
4
5
6
Description
1310 nm or 1550 nm optical signals from the headend are applied to receiver module 1 (and/or modules 2, 3, and 4, if used) in the 1.2 GHz GS7000 Node.
The receiver module detects the signal on the optical carrier applied to it and outputs an electrical RF signal to the node Optical Interface Board (OIB).
The RF signals travel across the OIB and cables to the Forward Configuration
Module (FCM). The FCM determines how RF signals from the different receiver modules are routed to the four independent forward amplification paths in the
RF amplifier module. The 1X4 FCM splits the RF signals entering it equally between the four forward amplification paths in the RF amplifier module.
Each of the forward amplification paths in the RF amplifier module is composed of one input amplification stage and one interstage amplification stages in series followed by a power doubler output amplification stage. This topology provides one driven output port for each of the forward amplification paths in the RF amplifier module, for a total of four driven node output ports.
Each of the forward amplification paths in the RF amplifier module also contains padding, trimming, thermal compensation, equalization, and filtering circuitry.
Node signal directors are present at two of the nodes forward output ports and allow the signals at those ports to be redirected to the nodes auxiliary output ports or split equally between the primary and auxiliary node output ports. In this way, the node can be configured to have up to six output ports.
21
Chapter 2 Theory of Operation
Reverse Path
Introduction
Reverse path refers to signals received by the node from the cable distribution network. These signals are amplified in the node and returned to the headend optically through the fiber portion of the network. The reverse path is not used in all networks.
Reverse Path Signal Routing
1.2 GHz GS7000 Node reverse path signal routing functions are described below.
Stage
1
2
Description
Reverse path RF signals are applied to node output ports 1, 2, 4, and 5. A fifth reverse path RF signal can be applied to node auxiliary output port 3 or 6 if the node is configured for local reverse path injection.
The RF signals from each of the four node output ports are amplified independently in the RF amplifier module and routed to the Reverse
Configuration Module (RCM).
3
4
Each of the reverse amplification paths in the RF amplifier module also contains padding, trimming, filtering, -6 db wink, and RF On/Off switch circuitry.
The RCM determines how RF signals from the different node output ports are combined and routed to the four transmitter module paths on the Optical
Interface Board (OIB). The 4X1 RCM combines the reverse path signals from the four node output ports together and directs them to the transmitter module 1 path on the OIB. (Note that other RCMs combine and direct signals to OIB transmitter module paths 2, 3, and 4 differently.)
5 The RF signals travel across the OIB to transmitter module 1 (and/or modules 2,
3, and 4, if used and proper RCM is installed.) The transmitter modulates the RF signals entering it onto an optical carrier and routes it through the fiber portion of the network back to the headend.
Note: Node output ports 3 and 6 can be configured as primary reverse ports. See
Reconfiguring Reverse Signal Routing (on page 113) for further details on this configuration.
22
Power Distribution
Power Distribution
Introduction
The 1.2 GHz GS7000 Node is powered by one or two power supplies.
Power Distribution
1.2 GHz GS7000 Node power distribution functions are described below.
Stage
1
2
3
4
5
Description
45 to 90 V AC is applied to one or two power supply modules in the 1.2 GHz
GS7000 Node.
The power supply module(s) convert(s) the AC input to +24.5, +8.5, -6.0, and
+5.5 V DC.
The +24.5, +8.5, -6.0, and +5.5 V DC lines are routed to 1.2 GHz GS7000 Node internal modules.
If two power supplies are installed and both are active, the load is shared equally between them.
An AC segmentable shunt is available to separate the AC connection to ports
1-3 from that of ports 4-6. This allows the node to be configured where one power supply is powered from ports 1-3 and a second power supply is powered from ports 4-6.
23
Chapter 2 Theory of Operation
RF Amplifier Module
Introduction
This section describes the RF amplifier module. The RF amplifier module contains the forward band and the reverse band amplifiers.
Functional Diagrams
The following diagrams show how the RF amplifier functions.
1.2GHz GS7000 Node
4 Way Forward Segmentable Launch Amplifier Module
AC 1
Power
AC 2
Power
Surge
Protection
Surge
Protection
Output
GaN
Gain Block
Interstage
GaAs
Gain Block
RF
Switch
RF
Switch
Interstage
GaAs
Gain Block
Fwd. TP
EQ Pad Pad
Trim
Pad Pad Trim Pad
Port 1
AC
Rev. TP
High
Low
Pad
A
J
DC
Switch
Ther Ther
DC
Switch
G
Pre
Amp
Port 2
Port 3
AC
Fwd. TP
Node Signal
Director
Jumper
Output
GaN
Gain Block
RF
Switch
AC
Rev. TP
Fwd. TP
Rev. TP
Aux. Reverse
Injection
Director
Field Accessable
Split Upgrade
Field Accessable
Plug-In
Factory
Plug-In
Pad
High
Low
EQ Pad
C
Pad B
High
210 MHz Aux.
Reverse Injection
Option
Low
Interstage
GaAs
Gain Block
Digital
Control
J
Tilt
Pre
Amp
Pad
Ther
Trim
Forward Configuration
R4
Module
R3 R2
Forward Input
Pad
Ther
Trim
R1
Pre
Amp
RF
Switch
Tilt
G
Interstage
GaAs
Gain Block
Pad
Digital
Control
EQ
E
Pad
Output
GaN
Gain Block
Option
Pad
210 MHz Aux.
Reverse Injection
EQ
D
F
Output
GaN
Gain Block
High
Low
Pad
Node Signal
Pad
High
Low
Director
Splitter
Aux. Reverse
Injection
Director
Fwd. TP
Rev. TP
Fwd. TP
Rev. TP
AC
AC
Fwd. TP
AC
Rev. TP
Port 4
Port 5
Port 6
24
RF Amplifier Module
LPF
LPF
LPF
LPF
Reverse Amplifier PWB
Reverse Amplifier IC with Integrated Attenuator
RF
Switch
Digital Att
(Off - 0 - 6 dB)
EN
Trim
Digital Control
RF
Switch
Digital Att
(Off - 0 - 6 dB)
Trim
EN
Digital Control
RF
Switch
Digital Att
(Off - 0 - 6 dB)
Trim
EN
Digital Control
RF
Switch
Digital Att
(Off - 0 - 6 dB)
Trim
EN
Digital Control
Reverse
Config.
Module
T4
T3
T2
T1
Reverse
Aux.
Jumper/
Comb./
Amp./
Term./
Module
T4 Pad
T3
Pad
T2 Pad
T1 Pad
Optical Interface PWB
Pad
R1
RF
Switch
Pad
Control
R2
Pad
R3 Pad
R4 Pad
Transmitter 4
Transmitter 3
Transmitter 2
Transmitter 1
Status Monitor or
Local Control Module
Receiver 1
Receiver 2
Receiver 3
Receiver 4
Power Supply 1
Power Supply 2
Field Accessable
Plug-In
Parallel
Output
To Forward
Amplifier
Reverse Amplifier
Digital Control Circuitry
Serial
Input
Field Accessable
Split Upgrade
Forward Band Amplification 4-Way Path Description
The RF amplifier module provides all forward signal amplification outside the optical receiver modules in the GS7000 Node.
The 4-way segmentable launch amplifier contains four independent forward amplification paths, each having one input near the center of the amplifier module and one, two or three outputs at one end of the amplifier module. Each of the forward paths is comprised of the forward configuration module, an input gain block, a frequency response trim circuit, a thermal compensation circuit, an inter-stage pad, a 2-way splitter or RF switch circuit, an inter-stage gain block, a plug-in forward band linear equalizer, an output pad, an output gain block, a diplex filter, a bi-directional 20 dB down forward test point, and finally an AC bypass circuit.
The thermal circuit on the RF amplifier module is designed to compensate for the RF forward path thermal movement of the entire node RF station. This includes the forward path amplifier module circuitry, RF cables, and optical interface board
25
Chapter 2 Theory of Operation
circuitry. It does not include the thermal movement of the optical receivers.
Forward Configuration Module
The forward configuration module determines the forward path topology in the RF amplifier module and the 1.2 GHz GS7000 Node. The output signals from one to four optical receivers enter the forward configuration module where they are combined and or directed to the two or four independent forward paths in the RF amplifier module. Forward path segmentation and/or redundancy are set by plugging the appropriate forward configuration module into the RF amplifier module. The forward configuration module is a plug-in, field accessible module. See
Forward Configuration Module (on page 29) for more information.
Forward Band Linear Equalizer Module
The forward band linear equalizer module sets the overall forward path tilt of the RF amplifier module and the 1.2 GHz GS7000 Node. The 1.2GHz GS7000 Node launch amplifier is shipped with four 18.0 dB linear equalizers installed in the RF amplifier module. One equalizer is installed in each of the four amplifier module forward paths. This sets the nodes forward path tilt to 17.5 dB linear. Forward band linear equalizer modules of other values are available. This allows the nodes forward path tilt to be adjusted as needed. The forward band linear equalizer module is a plug-in, field accessible module. See the equalizer charts in Appendix A - Technical
Information.
Node Signal Director Jumper/Splitter Module
The node signal director jumper/splitter module is a plug-in, field accessible module.
It is present on the center output ports on either end of the RF amplifier module. The orientation of these modules determines where the RF amplifiers center output port signals are directed. The node signal director jumper allows the center output port signals to be routed to either the amplifiers primary center output port or to its auxiliary corner output port. The node signal director splitter module splits the center output port signals equally between the primary and auxiliary output ports.
Auxiliary Reverse Injection Director Module
The auxiliary reverse injection director module is a plug-in module. It is accessible only after the RF amplifier modules cover has been removed. Auxiliary reverse injection director modules are present on the auxiliary corner output ports on either end of the RF amplifier module. The orientation of these modules determine if the nodes auxiliary output ports are configured to be primary or split node output ports, or local reverse injection ports.
26
RF Amplifier Module
Reverse Band Amplification Path Description
The RF amplifier module provides all reverse signal amplification outside the optical transmitter modules in the 1.2 GHz GS7000 Node. It contains four independent reverse paths comprised of an AC bypass circuit, a bi-directional 20 dB down reverse test point, a diplex filter, an input pad, a low pass filter, a 6 dB switched attenuator, a
16 dB gain block, a second low pass filter, an RF on/off switch, a frequency response trim circuit, and a reverse configuration module. The 6 dB switched attenuator and
RF on/off switch circuits allow each reverse path to have 6 dB (wink) and on/off capabilities. These circuits are controllable from the headend via the status monitor or locally via the local control module and a hand held controller. A serial communication link is provided between status monitor or local control module and the reverse band launch amplifier. Circuitry on the amplifier converts the serial communications to parallel control signals and routes them as needed.
The RF amplifier module also provides the routing for the auxiliary ports, 5 to 210
MHz reverse band local injection signals. Each of the two auxiliary port reverse band local injection paths is comprised of an AC bypass circuit, a bi-directional 20 dB down reverse test point, an input pad, and a reverse auxiliary jumper/amplifier/termination module. Signals from port 3 or port 6 of the nodes auxiliary path are directed by the reverse auxiliary/jumper/amplifier/termination module to the reverse configuration module.
Reverse Configuration Module
The reverse configuration module determines the reverse path topology in the RF amplifier module and 1.2 GHz GS7000 Node. The input signals from four independent amplifier module output ports and possibly the auxiliary reverse injection amplifier module port enter the reverse configuration module where they are combined and/or directed to one to four optical transmitters. Reverse path segmentation and or redundancy as well the ability to locally inject signals into the reverse path of the amplifier is set by plugging the appropriate reverse configuration module into the RF amplifier module. The reverse configuration module is a plug-in,
field accessible module. See Reverse Configuration Module (on page 34) for more
information.
Reverse Auxiliary Jumper/Combiner/Amplifier/Termination Module
The reverse auxiliary jumper/combiner/amplifier/termination module determines how reverse band signals, locally injected into the RF amplifier modules auxiliary ports, are routed within the amplifier module. The reverse auxiliary jumper module directs signals for one of the RF amplifiers auxiliary ports to the reverse configuration module.
The reverse auxiliary amplifier module amplifies signals for one or both of the RF
27
Chapter 2 Theory of Operation
amplifiers auxiliary ports and directs them to the reverse configuration module. The reverse auxiliary termination module terminates both auxiliary port reverse injection signal paths in 75 ohms as well as the path to the reverse configuration module.
28
Forward Configuration Module
Forward Configuration Module
Introduction
The forward configuration module determines the forward path topology in the RF amplifier module and the 1.2 GHz GS7000 Node. The output signals from one to four optical receivers enter the forward configuration module where they are combined or directed to the four independent forward paths in the RF amplifier module. The various types of the forward configuration module are described below.
1x4 Forward Configuration Modules Description
The 1x4 Forward Configuration Module is used when the 1.2 GHz GS7000 Node is configured with a single optical receiver routed to all four outputs of the RF amplifier module. This module splits the signals equally to the inputs of the RF amplifier module.
The following diagram shows how this module functions.
1x4 Forward Configuration Modules with Forward RF Injection
Description
The 1x4 Forward Configuration Modules with forward RF injection are similar to the
1x4 Forward Configuration Modules, but are used with the Forward Local Injection
(FLI) Module. The FLI Module routes an RF signal from an external source to the
Forward Configuration Module which is then coupled with other inputs from an optical receiver.
The following diagram shows how this module functions.
29
Chapter 2 Theory of Operation
1x4 Redundant Forward Configuration Modules Description
The 1x4 Redundant Forward Configuration Module is used when the 1.2 GHz
GS7000 Node is configured with two optical receivers routed to all four outputs of the amplifiers in a redundant configuration. Receiver 1 is the primary receiver and
Receiver 2 is the backup. The active receiver is selected with a digital signal from the status monitor/local control module.
The following diagram shows how this module functions.
30
1x4 Redundant Forward Configuration Modules with Forward RF
Injection Description
The 1x4 Redundant Forward Configuration Modules with forward RF injection are similar to the 1x4 Redundant Forward Configuration Modules, but are used with the
Forward Local Injection (FLI) Module. The FLI Module routes an RF signal from an external source to the Forward Configuration Module which is then coupled with other inputs from an optical receiver.
The following diagram shows how this module functions.
Forward Configuration Module
2x4 Forward Configuration Modules Description
The 2x4 Forward Configuration Module is used when the 1.2 GHz GS7000 Node is configured with two optical receivers, each feeding two outputs of the amplifier module. In this configuration, the node serving area is divided in half in the forward direction. Receiver 1 is routed to RF amplifier Ports 4 and 5/6, while Receiver 3 is routed to RF amplifier Ports 1 and 2/3.
The following diagram shows how this module functions.
2x4 Redundant Forward Configuration Modules Description
The 2x4 Redundant Forward Configuration Module is used when the 1.2 GHz
GS7000 Node is configured with four optical receivers with each pair feeding two RF outputs of the amplifier module in a redundant configuration. In this configuration, the node serving area is divided in half for redundancy in the forward direction.
Receivers 1 (primary) and 2 (redundant) are routed to RF amplifier Ports 4 and 5/6, while Receivers 3 (primary) and 4 (redundant) are routed to RF amplifier Ports 1 and
2/3. The active receiver is selected with digital signal from the status monitor/local control module.
The following diagram shows how this module functions.
31
Chapter 2 Theory of Operation
3x4-1, 3, 4 Forward Configuration Module Description
The 3x4-1, 3, 4 Forward Configuration Module is used when the 1.2 GHz GS7000
Node is configured with three receivers each feeding one/two/three/four outputs of the amplifier module. Receiver 1 is routed to RF amplifier ports 4/5/6, Receiver 3 is routed to port 1, and Receiver 4 is routed to ports 2/3.
Note: The 3x4-1, 3, 4 FCM can only be used with the 4-way RF amplifier module.
The following diagram shows how this module functions.
32
3x4-1, 2, 4 Forward Configuration Module Description
The 3x4-1, 2, 4 Forward Configuration Module is used when the 1.2 GHz GS7000
Node is configured with three receivers each feeding one/two/three/four outputs of the amplifier module. Receiver 1 is routed to RF amplifier ports 5/6, Receiver 2 is routed to port 4, and Receiver 4 is routed to ports 1/2/3.
Note: The 3x4-1, 2, 4 FCM can only be used with the 4-way RF amplifier module.
The following diagram shows how this module functions.
Forward Configuration Module
4x4 Forward Configuration Module Description
The 4x4 Forward Configuration Module is used when the 1.2 GHz GS7000 Node is configured with four optical receivers with each feeding separate RF outputs of the amplifier module. Receiver 1 is routed to RF amplifier Ports 5/6. Receiver 2 is routed to RF amplifier Port 4. Receiver 3 is routed to RF amplifier Port 1. Receiver 4 is routed to RF amplifier Ports 2/3.
Note: The 4x4 FCM can only be used with the 4-way RF amplifier module.
The following diagram shows how this module functions.
33
Chapter 2 Theory of Operation
Reverse Configuration Module
Introduction
The reverse configuration module determines the reverse path topology in the RF amplifier module and 1.2 GHz GS7000 Node. The input signals from four independent amplifier module output ports enter the reverse configuration module where they are combined and/or directed to one to four optical transmitters. The various types of the reverse configuration module are described below.
4x1 Reverse Configuration Module with Auxiliary Reverse RF Injection
Description
The 4x1 Reverse Configuration Module with auxiliary reverse RF injection combines all four reverse RF inputs (Ports 1, 2/3, 4, and 5/6) of the node and routes the signal to Transmitter 1. An RF signal from an external source can optionally be injected and coupled with the reverse RF inputs on Ports 3/6 and routed to Transmitter 1.
The following diagram shows how this module functions.
34
4x1 Redundant Reverse Configuration Module Description
The 4x1 Redundant Reverse Configuration Module combines all four reverse RF signals (Ports 1, 2/3, 4 and 5/6) together, splits this RF signal and routes it to
Transmitters 1 and 2.
The following diagram shows how this module functions.
Reverse Configuration Module
4x2 Reverse Configuration Module with Auxiliary Reverse RF Injection
Description
The 4x2 Reverse Configuration Module with auxiliary reverse RF injection combines reverse inputs from Ports 1 and 2/3 and routes them to Transmitter 1; it also combines reverse inputs from Ports 4 and 5/6 and routes them to Transmitter 3. An
RF signal from an external source can optionally be injected and coupled with reverse RF inputs from Ports 3/6 and routed to Transmitter 1.
Note: This module can only be used with an 8-port optical interface board. (There is no transmitter 3 position with a 6-port optical interface board.)
The following diagram shows how this module functions.
4x2 Redundant Reverse Configuration Module Description
The 4x2 Redundant Reverse Configuration Module combines reverse inputs from
Ports 1 and 2/3 and routes them to Transmitters 1 and 2; it also combines reverse inputs from Ports 4 and 5/6 and routes them to Transmitters 3 and 4.
The following diagram shows how this module functions.
35
Chapter 2 Theory of Operation
4x3-1, 2, 4 Reverse Configuration Module with Auxiliary Reverse RF
Injection Description
The 4x3-1,2,4 Reverse Configuration Module with auxiliary reverse RF injection combines reverse inputs from Ports 4 and 5/6 and routes them to Transmitter 4; it also routes reverse inputs from Port 1 to Transmitter 1 and from Ports 2/3 to
Transmitter 2. An RF signal from an external source can optionally be injected at
Ports 3/6 and coupled with the reverse RF input from Port 1 and routed to
Transmitter 1.
The following diagram shows how this module functions.
36
4x3-1,3,4 Reverse Configuration Module with Auxiliary Reverse RF
Injection Description
The 4x3-1,3,4 Reverse Configuration Module with auxiliary reverse RF injection combines reverse inputs from Ports 1 and 2/3 and routes them to Transmitter 1; it also routes reverse inputs from Port 4 to Transmitter 3 and from Ports 5/6 to
Transmitter 4. An RF signal from an external source can optionally be injected at
Ports 3/6 and coupled with the reverse RF inputs from Ports 2/3 and 1 and routed to Transmitter 1.
The following diagram shows how this module functions.
Reverse Configuration Module
4x4 Reverse Configuration Module with Auxiliary Reverse RF Injection
Description
The 4x4 Reverse Configuration Module with auxiliary reverse RF injection routes reverse inputs from Port 1 to Transmitter 1, from Port 2/3 to Transmitter 2, from
Port 4 to Transmitter 3, and from Port 5/6 to Transmitter 4. An RF signal from an external source can optionally be injected and coupled with reverse RF inputs from
Ports 3/6 and routed to Transmitter 1.
Note: This module is typically installed when using EDR multiplexing digital reverse modules. Since the digital reverse module occupies the physical space that transmitters 3 and 4 normally occupy in the node base, this reverse configuration module is typically used with a 6-port optical interface board.
The following diagram shows how this module functions.
37
Chapter 2 Theory of Operation
Optical Interface Board (OIB)
Optical Interface Board Description
The Optical Interface Board (OIB) provides all interconnections between the modules in the housing lid of the 1.2 GHz GS7000 Node. The modules in the housing lid include the optical receiver, optical transmitter, power supply, and status monitoring/local control modules. Each module in the lid plugs directly into the
OIB through a connector header or row of sockets. Input attenuator pads are provided on the OIB for each optical receiver in the housing lid. Output attenuator pads are provided on the OIB for each optical transmitter in the housing lid. All RF and power cables running between the housing lid and base also plug into the OIB.
The OIB is field replaceable. All optical modules, power supplies, RF cables, power cables, and OIB mounting screws must be removed in order to remove the OIB from the housing lid.
The upstream status monitoring signal goes through LPF then splits. Splitter output
1 goes through a 17dB coupler into transmitter 1 input. Splitter output 2 goes through a plug-in attenuator pad, a 17dB coupler and into transmitter 2 input.
The purpose of the attenuator (AT9) is to terminate the upstream status monitoring signal going into transmitter 2 when either the node is segmented or EDR transmitter is in use. When the node is configured in either segmented or EDR mode, a 75 dB pad must be placed in the Tx2 SM Term.
This solution resolves the issue of transmitting and receiving duplicate copy of the upstream signal from transponder at the CMTS.
38
Optical Receiver Module
Optical Receiver Module
Optical Receiver Module Description
The optical receiver module takes in optical signals and puts out forward band RF signals. The module cover has a sliding tray incorporated into it allowing the receivers fiber pigtail to be spooled up and contained within the receiver module.
This greatly improves fiber management within the node.
The optical receiver modules plug directly into the optical interface board via a connector header and are secured in place with two screws. Input attenuator pads are provided on the optical interface board for each receiver mounted in the housing lid.
All optical receiver test points are provided and are accessible through holes in the module housing. The optical power test points for the optical receiver module has a scaling ratio of 1 V = 1 mW. A -20 dB RF power test point is accessible through the front panel.
The optical receiver module has an optical power LED to indicate the presence of optical power that is either above or below the specified range. ON indicates optical power is within operating limits and OFF indicates that optical power is below the alarm threshold.
The optical power level into the optical receiver module is monitored by the status monitor or local control module. When the node is setup for redundant optical receiver operation, a digital signal is generated by the status monitor or local control module to switch between the primary and redundant optical receiver module in the forward configuration module.
39
Chapter 2 Theory of Operation
There are two types of the receiver module: Standard Input Optical Receiver and
Low Input Optical Receiver.
The optical input range for the low input receiver is 0.1 w to 0.63 w (-10 dBm to -2 dBm). Compared to the standard input optical receiver (the optical input range is -6 dBm to +2 dBm (0.25 w to 1.58 w)), the low input optical receiver can work with lower optical input level, in order to support fiber deep applications.
40
Optical Receiver Module
The illustration below is Low Input Receiver RF Output Level and Transmitter OMI:
Rx Switch in 0 dB Setting:
Minimum
RF Output
Level
(dBmV)
36.5
36.0
35.5
35.0
34.5
34.0
33.5
33.0
32.5
32.0
31.5
31.0
30.5
Input Power
29.5
29.0
2.25% 2.50% 3.75% 4.00% 2.75% 3.00% 3.25%
Transmitter OMI per Channel
3.50%
1310nm 1550nm
The illustration below is Low Input Receiver RF Output Level and Transmitter OMI:
Rx Switch in -8 dB Setting:
28.5
28.0
27.5
27.0
26.5
26.0
Minimum
RF Output
Level
(dBmV)
25.5
25.0
24.5
24.0
23.5
23.0
-6dBm Optical
Input Power
22.5
22.0
21.5
21.0
2.25% 2.50% 3.75% 4.00% 2.75% 3.00% 3.25% 3.50%
Transmitter OMI per Channel
1310nm 1550nm
For the detailed information about the low input optical receiver, please refer to the latest GS7000 Data Sheet.
41
Chapter 2 Theory of Operation
Optical Receiver Module Diagram
The following diagram shows how the optical receiver module functions.
42
Optical Analog Transmitter Modules
Optical Analog Transmitter Modules
Optical Analog Transmitter Module Descriptions
The optical analog transmitter module takes in reverse band RF signals and puts out optical signals. The 1.2 GHz GS7000 Node is designed to work specifically with the existing mid gain, temperature compensated DFB optical transmitters. Other mid and high gain optical transmitters may be installed in the 1.2 GHz GS7000 Node with varying effects on the overall node specifications. The new module cover fits on all existing optical transmitters. This module cover has a sliding tray incorporated into it allowing the transmitters fiber pigtail to be spooled up and contained within the transmitter module. This greatly improves fiber management within the node.
The optical transmitter modules plug directly into the optical interface board via a connector header and are secured in place with two screws. Output attenuator pads are provided on the optical interface board for each transmitter mounted in the housing lid.
RF test points are accessible through holes in the module housing. The optical power test point for the optical transmitter module has a scaling ratio of 1 V = 1 mW. A -20 dB RF power test point is accessible through the module top cover.
The top cover contains a status monitor LED. Each optical transmitter module laser power indicator turns off when the laser power output falls outside the alarm threshold. It is on (green) when within the alarm threshold.
43
Chapter 2 Theory of Operation
Optical Analog Transmitter Module Diagram
This illustration shows how the optical analog transmitter module functions.
44
Optical Amplifier (EDFA) Modules
Optical Amplifier (EDFA) Modules
Optical Amplifier Module Descriptions
Erbium-doped fiber amplifier modules are available in two categories: broadcast and narrowcast (gain-flattened). Broadcast EDFAs are used for the amplification of broadcast signals which are carried by a single optical channel anywhere between
1530 nm and 1565 nm. (Gain-flattened) EDFAs are used for the amplification of multiple optical channels. For uniformity of performance, EDFAs need to be gain flattened in the designated operating wavelength range between 1536 nm and 1562 nm.
Broadcast EDFAs are available in 17 dBm, 20 dBm, and 22 dBm versions.
Narrowcast (gain-flattened) EDFAs are available in 17 dBm, 20 dBm, and 21 dBm versions to fit any architecture for requirements like DWDM narrowcasting.
Both broadcast and (gain-flattened) EDFAs can be operated in constant power and constant gain modes. The default setting for a broadcast EDFA is constant power mode, while the default setting for a (gain-flattened) EDFA is constant gain mode.
The table below lists the part number and description of the new gain-flattened
EDFA:
Part Number
GS7K-GFEDFA-17L=
GS7K-GFEDFA-17H=
GS7K-GFEDFA-21L=
Description
17 dBm gain flattened low gain EDFA
17 dBm gain flattened high gain EDFA
21 dBm gain flattened low gain EDFA
45
Chapter 2 Theory of Operation
Part Number
GS7K-GFEDFA-21H=
Description
21 dBm gain flattened high gain EDFA
EDFA modules are single-wide, single-output devices. Each module is connected to one input fiber and one output fiber through optical fiber connectors on the side of the module housing. The modules can be mounted in either receiver or transmitter slots on the optical interface board in the node lid using a reversible pin adaptor. The pin adaptor is used to adapt the module to the connector arrangement for a transmitter slot or a receiver slot, which are different. To mount the module in a transmitter slot the red side of the pin adaptor must face out. To mount the module in a receiver slot the blue side of the pin adaptor must face out.
Refer to Optical Amplifier and Optical Switch Module Pin Adaptor (on page 128)
for pin adaptor installation instructions.
46
Optical Amplifier (EDFA) Modules
Optical Amplifier Module Diagram
The following block diagram shows how the optical amplifier module functions.
Optical Amplifier Operating Parameters
This section is a reference for the operating parameters of the EDFA. The EDFA is configured through the Status Monitor/Local Control Module in the housing lid.
Refer to the GS7000 Hub/Node Status Monitor/Local Control Module Installation and
Operation Guide, part number OL-29937, for complete instructions on configuring the
EDFA.
Configurable Parameters
The following table defines the configurable parameters for the EDFA.
47
Chapter 2 Theory of Operation
48
Param
Name
Mode
Products
All
Enable All
Set
Power
BCST 17
BCST 20
BCST 22
GF 17
GF 21
Set Gain BCST 17
BCST 20
BCST 22
GF 17L
GF 17H
GF 21L
GF 21H
Function
Sets operating mode of amplifier
Default
Value
[A]
Min Typical Max Step
na na na
Enables or disables amplifier
Sets optical output level [B]
Sets optical output level [B]
Sets optical output level [B]
Sets optical output level [B]
Sets optical output level [B]
Sets gain level in
Constant Gain
Mode [A][B]
Sets gain level in
Constant Gain
Mode [A][B]
Sets gain level in
Constant Gain
Mode [A][B]
[A]
[A]
[A]
[A]
Off(0)
17
20
22
17
21
12
15
17
7
12
11
16 na
14
17
19
14
18
10
13
15
5
10
9
14 na
17
20
22
17
21
12
15
17
7
12
11
16 na
17
20
22
17
21
14
17
19
9
14
13
18
[A] For the Broadcast amplifier, the default is Constant Power. For the
(gain-flattened) amplifier, the default is Constant Gain.
[B] In Constant Power mode only.
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
Unit
Constant
Gain (0)
Constant
Power (1)
Off(0)
On(1)
0.1 na na dBm dBm dBm dBm dBm dB dB dB dB dB dB dB
Optical Amplifier (EDFA) Modules
Operating Status Parameters
The following table defines the monitored operating parameters for the EDFA.
Parameter Name
Optical Input Power
Output Power
Laser Temperature
Laser Bias Current
Limit
Laser Bias Current
TEC Current
Module Temperature
Laser On Time
Function
Optical input power
Optical output power
Laser temperature
Laser operating current limit
Typical Value Units
5.0 dBm
19.5
25.0
0.825 dBm degC
A
Laser operating current 0.625
Thermoelectric cooler current 0.25
Module temperature
Time the laser has been on
26.5
1.0
Alarm Parameters
The following table defines the alarm parameters for the EDFA.
A
A degC
Hrs
Alarm Name Major
High
Laser Bias
Current
Minor
High
Minor
Low
-0.001 -0.010 na
Optical
Output Level
1.0 0.7 -0.7
Major
Low
na
-1.0
Input Power
[1]
Laser
Temperature
[1][4]
OIB Voltage
Status [1][2]
Internal
Power Status
[1][3]
[5]
20.0 na na
[5]
15.0 na na
[5]
-15.0 na na
[5]
-20.0 na na
Values Typical
Value
Ok
Alarm
0.625
Ok
Alarm
17
20
21
22 na Ok
Alarm
Ok
Alarm
25.0
Hysteresis Units
0.001
0.1
0.1
1.0
A dBm dBm degC
Ok
Alarm
Ok
Alarm
Ok na na na na na
49
Chapter 2 Theory of Operation
Alarm Name Major
High
Laser
Enabled
Status [1] na
Minor
High
na
Minor
Low
na
Major
Low
na
Values Typical
Value
Ok
Alarm na
Hysteresis Units
na na
[1] This alarm sets the unit to the safe state. In the safe state, the amplifier is turned off causing the optical amplifier output to be disabled.
[2] This alarm tests for presence of +24V, -6V from the OIB.
[3] This alarm indicates the state of the internal voltages (+24V, +5.0V, Vref).
[4] See following for laser nominal set point temperature based on module temperature.
[5] See next table for input power alarm values.
Input Power Alarm Parameters
The following tables define the input power alarm parameters for the EDFA.
(Gain-flattened) EDFA - Constant Gain Mode (Default)
Product Type
17.0 / 20.0 /21.0 dBm Low Gain
Major
High
45.0
17.0 / 20.0 /21.0 dBm High Gain
45.0
Minor
High
25.0
25.0
Minor
Low
-8.0
Major
Low
-10.0
Values Typical
Value
Ok
Alarm
-7.0
-13.0 -15.0 Ok
Alarm
-12.0
(Gain-flattened) EDFA - Constant Power Mode
Hysteresis Units
0.1
0.1 dBm dBm
Product Type
17.0 / 20.0 /21.0 dBm
Low/High Gain
Major
High
45.0
Minor
High
25.0
Minor
Low
0
Major
Low
-10.0
Values Typical
Value
Ok
Alarm
5.0
Broadcast EDFA - Constant Power Mode (Default)
Hysteresis Units
0.1 dBm
Product Type Major
High
Minor
High
Minor
Low
Major
Low
Values Typical
Value
Hysteresis Units
50
Optical Amplifier (EDFA) Modules
17.0/20.0/22.0 dBm
45.0 25.0 0
Broadcast EDFA - Constant Gain Mode
-10.0 Ok
Alarm
5.0 0.1 dBm
Product Type
17.0/20.0/22.0 dBm
Major
High
45.0
Minor
High
25.0
Minor
Low
-13.0
Major
Low
-15.0
Values Typical
Value
Ok
Alarm
-12.0
Hysteresis Units
0.1 dBm
Laser Temperature Set Point Adjustment
In an effort to reduce EDFA power consumption, laser temperature set point is changed based on EDFA module temperature. Typically, the laser temperature set point is set at 25°C. When module temperature is greater than 60°C and less than
10°C, laser temperature set point is adjusted.
Hot Condition (Module Temperature > 60° C)
For module temperature less than 60.0°C, laser set point temperature is set at 25°C.
For every degree of module temperature greater than 60°C, laser set point temperature is also increased by that amount until module temperature reaches 70°C, then laser temperature set point is fixed at 35°C. For example, if module temperature is 64°C, laser set point temperature is 29°C. If module temperature is 85°C, laser set point temperature is 35°C.
Cold Condition (Module Temperature < 10° C)
For module temperature greater than 10°C, laser set point temperature is set at 25°C.
For every degree of module temperature less than 10°C, laser set point temperature is also decreased by that amount until the module temperature reaches -5°C, then laser temperature set point is fixed at 10°C. For example, if module temperature is
-4°C, laser set point temperature is 11°C. If module temperature is -25°C, laser set point temperature is 10°C.
51
Chapter 2 Theory of Operation
Optical Switch Module
Optical Switch Module Description
The optical switch module is used for switching the input of an EDFA module from a primary signal to a backup or secondary signal. The switch operates in the 1550 nm wavelength range since its application is high power/long haul systems that employ
EDFAs.
The switch has two operating modes: manual and automatic. In automatic mode, the switch can be triggered by a loss of light. The loss of light activation triggers the switch when the light level drops below the threshold value set by the operator. In manual mode, the switch can be triggered through the Local Control Module (LCM).
52
The module mounts in receiver or transmitter slots on the optical interface board in the node lid using a reversible pin adaptor. The pin adaptor is used to adapt the module to the connector arrangement for a transmitter slot or a receiver slot, which are different. To mount the module in a transmitter slot the red side of the pin adaptor must face out. To mount the module in a receiver slot the blue side of the pin adaptor must face out.
Refer to Optical Amplifier and Optical Switch Module Pin Adaptor (on page 128)
for pin adaptor installation instructions.
Optical Switch Module
Optical Switch Module Diagram
The following block diagram shows how the optical switch module functions.
Optical Switch Operating Parameters
This section is a reference for the operating parameters of the optical switch. The optical switch is configured through the Status Monitor/Local Control Module in the node. Refer to the GS7000 Hub/Node Status Monitor/Local Control Module
Installation and Operation Guide, part number OL-29937, for complete instructions on configuring the optical switch.
53
Chapter 2 Theory of Operation
Switch Operation
The following table describes the optical switch function.
Primary Input
Path A Optical Power >
ThresholdA (default)
Path A Optical Power <
ThresholdA (default)
Path B Optical Power >
Threshold B [1]
Path A Optical Power <
ThresholdA (default)
Path B Optical Power >
ThresholdB (User Setting)
Path B Optical Power <
ThresholdB (User Setting)
Path B Optical Power >
ThresholdB (User Setting)
Path B Optical Power <
ThresholdB (User Setting)
Secondary Input
Path B Optical Power >
Threshold B [1]
Path B Optical Power >
Threshold B [1]
Path B Optical Power <
Threshold B [1]
Path B Optical Power <
Threshold B [1]
Path A Optical Power >
ThresholdA [1]
Path A Optical Power >
ThresholdA [1]
Path A Optical Power <
ThresholdA [1]
Path A Optical Power <
ThresholdA [1]
Alarms
None
Loss of Input
Light at Path A
Loss of Input
Light at Path B
Both Dark
None
Loss of Input
Light at Path B
Loss of Input
Light at Path A
Both Dark
Optical Switch
Switch to Path A
Switch to Path B
Optical Power
Switch to Path A
Switch to Path A
Optical Power
Switch to Path B
Switch to Path A
Optical Power
Switch to Path B
Switch to Path B
Optical Power
[1] Hysteresis Amplitude (default 1.0 dB) is the value above which the input optical power must rise for the switch to begin sequence to return to the primary switch position. Hysteresis Amplitude is a user configurable parameter.
Configurable Parameters
The following table defines the configurable parameters for the optical switch.
Parameter Function
Mode Automatic or manual mode
Threshold B Switching threshold, input optical power at input B
Default
Value
Auto(0)
5.0
Values Min Max
Auto(0)
Manual(1)
-10.0 14.0
Step Unit
0.1 dBm
54
Optical Switch Module
Parameter Function
Threshold A Switching threshold, input optical power at input A
Hysteresis
Amplitude
Hysteresis
Time
Revert
Hysteresis
Amplitude: The value (in dB relative to the switching threshold) above which the input optical power must raise for the switch to begin the hysteresis timer before restoring primary switch position. Only applies if Revert is
On.
Hysteresis Time: The length of time, in seconds, that primary optical power must remain above the restore threshold before switch is allowed to revert to primary position.
Only applies if Revert is On.
On (1) allows switch to revert to primary position after optical power restored. In
Off (0), switch will remain in backup
(non-primary) position.
Primary
Optical
Input
Switch
Position
Selects the primary optical input
Selects the Normal switch position
Default
Value
5.0
1.0
60
On(1)
Values
Off(0)
On(1)
PathA(0) PathA(0)
PathB(1)
PathA(0) PathA(0)
PathB(1)
Min
-10.0
0.5
0 na na na
Max
14.0
9.5
600 na na na
Step Unit
0.1 dBm
0.1
1 na na na dB sec na na na
55
Chapter 2 Theory of Operation
Operating Status Parameters
The following table defines the monitored operating parameters for the optical switch.
Parameter Name
Switch Position
Function
Read optical switch position
(Calibrated at 1550 nm only)
Path A Optical Power Input optical power on Path A
(Calibrated at 1550 nm only)
Typical Operating Range
PathA/PathB
-10 to 14
Path B Optical Power Input optical power on Path B -10 to 14
Module Temp Module temperature Ambient temp + 7
Switch Temp Switch temperature Ambient temp + 7
Alarm Parameters
The following table defines the alarm parameters for the optical switch.
Units
state dBm dBm degC degC
Alarm Name
Loss of Input
Light at Path A
Loss of Input
Light at Path B
Both Dark
No Switch
Power Supply
OK
Excessive Input
Optical Power
Error Condition
Optical input at path A is less than the switching threshold at path A
Optical input at path B is less than the switching threshold at path B
Loss of light at both inputs
(Loss of Input Light at Path A and Loss of
Input Light at Path B)
Optical switch failed to change states when commanded
Failure of external power supply rails
Optical input at Path A or optical input at
Path B is greater than or equal to 24 dBm
Values
Minor Alarm(0)
Ok(1)
Minor Alarm(0)
Ok(1)
Major Alarm(0)
[2]
Ok(1)
Major Alarm(0)
[2]
Ok(1)
Major Alarm(0)
[2]
Ok(1)
Major Alarm(0)
[2]
Ok(1)
Hysteresis
[1]
[1]
56
Optical Switch Module
[1] Hysteresis Amplitude (default 1.0 dB) is the value above which the input optical power must rise for the switch to begin sequence to return to the primary switch position. Hysteresis Amplitude is a user configurable parameter.
[2] In some cases this may display as Fault (0).
57
Chapter 2 Theory of Operation
Local Control Module
Overview
A local control module and a status monitor are available for the 1.2 GHz GS7000
Node and Hub Node. A status monitor consists of a local control module with a transponder core module installed in the housing. The same housing is used for both units. The units perform the following function:
Local Control Module - controls redundancy and forward segmentation, and configures the modules
Status Monitor - adds status monitoring capability to the local control module
DOCSIS capability
Status Monitor Description
The status monitor is HMS compliant and provides node monitoring and control capability at the cable plant's headend. The following node voltages and signals are monitored and their status reported to the headend by the status monitor.
Receiver optical input level (all receivers)
Transmitter optical output level (all transmitters)
AC power presence and peak voltage (for split AC powering cases, AC power from both sides of node housing is monitored)
DC voltages from both primary and redundant power supplies
Optical amplifier operating parameters
Optical switch operating parameters
Commands are sent from the headend to the status monitor. The status monitor communicates serially with the RF amplifier module to control the optional forward band redundancy switches on the forward configuration module, the reverse band 6 dB (wink) attenuators on the reverse amplifier PWB, and the reverse band on/off switches on the reverse amplifier PWB.
Note: Configuration parameters for the transponder core module, such as IP address, can be changed using the PC-based GS7000 ViewPort software.
58
Local Control Module
Note: The transponder core module can be seen through the Heart
Beat/Receive/Error indicator cutout in the cover.
Local Control Module Description
The local control module locally monitors the following node voltages and signals:
Receiver optical input level (all receivers)
Transmitter optical output level (all transmitters)
AC power presence and peak voltage (for split AC powering cases, AC power from both sides of node housing is monitored)
DC voltages from both primary and redundant power supplies
Optical amplifier operating parameters
Optical switch operating parameters
The local control module communicates serially with the RF amplifier module to control the optional forward band redundancy switches on the forward
59
Chapter 2 Theory of Operation
configuration module. It is a low-cost module that plugs into the status monitor connectors on the optical interface board.
The local control module is equipped with a USB port to allow local control of the optional forward band redundancy switches, the reverse band 6 dB (wink) attenuators, the reverse band on/off switches, the optical switch, and optical amplifiers through the PC-based GS7000 ViewPort software. All parameters monitored by the local control module can be displayed and reviewed using
ViewPort.
60
Note: The local control module can be upgraded to a status monitor through the addition of a transponder core module. The transponder core module plugs directly onto the local control module’s PWB. The mechanical housing for the status monitor and the local control module are the same. The Heart Beat, Receive, and Error indicator LEDs are only present if the transponder module is installed.
Power Supply Module
Power Supply Module
Power Supply Module Description
The power supply module converts a quasi-square wave, 50 – 60 Hz AC input voltage into four well-regulated DC output voltages. The supply is an off-line, switched-mode power supply with a large operative input range. This reduces service outages by converting long duration AC surges into load power. The power supply is a constant power device, meaning that it automatically adjusts its internal operating parameters for the most efficient use of the different levels of input voltage and current it will receive within the cable plant.
The DC output voltages generated by the power supply, at given load currents, are shown below:
+24.5 VDC @ 6.2 Amps
+8.5 VDC @ 1.0 Amps
+5.5 VDC @ 1.3 Amps
-6.0 VDC @ 0.8 Amps
Test points are provided on top of the power supply module for AC input and all output DC voltage rails.
61
Chapter 2 Theory of Operation
62
The power supply module plugs directly into the optical interface board, no external cables are required.
A 1.2 GHz GS7000 Node can be configured with one or two power supplies. AC input voltage can be routed to both power supplies commonly from any node output port. In addition, AC input voltages can be routed in a split fashion to the two power supplies. AC input voltages from the left half of the node (output ports 1
– 3) can be routed to power supply 1 independent of AC input voltages from the right half of the node (output ports 4 – 6) being routed to power supply 2. Each of the power supplies output voltage rails is diode OR'd within the supply. This creates common DC powering circuits when multiple supplies are present in the node.
Power Supply Module
Node Power Limitations
Nodes and hub nodes must be configured in a manner that prevents potential thermal overloads. Heat generated by the node can reduce the life of the equipment.
CAUTION:
The life of the equipment may be reduced if configured to draw more than the
recommended level of power from the power supplies.
Two power supplies can provide a maximum power level of 100 watts to the node or hub node. The RF amplifier uses the majority of the available power. Maintain the total power consumption of all modules in the housing within these guidelines to minimize the heat generated. Find the optimal configuration by summing the power consumption of the RF amplifier plus the other individual modules in the housing using the following table.
Important: Do not populate the housing with any combination of modules that would draw more than the available power of 100 watts.
The following table lists the modules and their respective power consumption.
Equipment Type Maximum Power
Draw (Watts)
4.1
Typical Power
Draw (Watts)
3.4 Transmitter
Transmitter
Standard Input
Receiver
Standard Input
Receiver
Low Input Receiver
Low Input Receiver
EDFA
EDFA
EDFA
Optical Switch
Status Monitor/ Local
Control Module
RF Amplifier
1310 nm dfb, analog CWDM analog DWDM operating standby operating standby
17 dBm
20 dBm
22 dBm
4-way forward segmentable
5.4
4.1
0.5
4.1
0.5
4.5
7
9
2
2.6
72.8
4.8
3.9
0.4
7
1.5
0.9
4
5
3.85
0.4
72.9
63
Chapter 2 Theory of Operation
1:1 EDR Transmitter
2:1 EDR Transmitter
< 3
< 7
64
3
Chapter 3
Installation
Introduction
This chapter describes the installation of the 1.2GHz GS7000 Node.
In This Chapter
Tools and Test Equipment ................................................................... 66
Node Housing Ports ............................................................................. 68
Strand Mounting the Node ................................................................. 69
Pedestal or Wall Mounting the Node ................................................ 72
Fiber Optic Cable Installation ............................................................. 74
Applying Power to the Node .............................................................. 85
65
Chapter 3 Installation
Tools and Test Equipment
Required Tools and Test Equipment
The following tools and equipment are required for installation.
Torque wrench capable of 5 to 12 ft-lbs (6.8 to 16.3 Nm)
4-inch to 6-inch extension for torque wrench
1/2-inch socket for strand clamp bolts and cover bolts
1/4-inch flat-blade screwdriver
#2 Phillips-head screwdriver
Long-nose pliers
1/2-inch deep-well socket for seizure connector
True-rms digital voltmeter (DVM)
EXFO FOT 22AX optical power meter with adapters
Optical connector cleaning supplies
Optical connector microscope with appropriate adapters for your optical connectors
66
Node Fastener Torque Specifications
Be sure to follow these torque specifications when assembling/mounting the node.
Fastener
Housing closure bolts
Torque Specification
5 to 12 ft-lbs
(6.8 to 16.3 Nm)
Illustration
Test point port plugs
Housing plugs
5 to 8 ft-lbs
(6.8 to 10.8 Nm)
Strand clamp mounting bracket bolts 5 to 8 ft-lbs
(6.8 to 10.8 Nm)
Pedestal mounting bolts
Module securing screws
(Tx, Rx, PS, and SM/LCM modules)
8 to 10 ft-lbs
(10.8 to 13.6 Nm)
25 to 30 in-lbs
(2.8 to 3.4 Nm)
Fastener
RF Amplifier assembly shoulder screws (cross head screw)
Seizure nut
RF cable connector
Fiber optic cable connector
Tools and Test Equipment
Torque Specification
18 to 20 in-lbs
(2.0 to 2.3 Nm)
2 to 5 ft-lbs
(2.7 to 6.8 Nm)
Illustration
Per manufacturer instructions
20 to 25 ft-lbs
(27.1 to 33.9 Nm)
67
Chapter 3 Installation
Node Housing Ports
The following illustration shows the location of available RF ports, fiber ports, and test points on the 1.2 GHz GS7000 Node housing.
Notes:
External test points are only active on models with the "Amplifier Type 3 -
External Test Points Activated" option.
When replacing test point port plugs, torque from 5 to 8 ft-lbs (6.8 to 10.8 Nm).
68
Strand Mounting the Node
Strand Mounting the Node
Description
The following procedure explains how to install the 1.2 GHz GS7000 Node on a strand (aerial installation). Strand mounting allows street-side access to the housing.
Procedure
Follow this procedure to mount the housing to a strand. The housing does not need to be opened for strand installation.
WARNING:
Be aware of the size and weight of the node while strand mounting.
Ensure that the strand can safely support the node’s maximum weight.
A fully loaded 1.2 GHz GS7000 Node weighs over 50 lbs (22.7 kg).
Ensure the ground area below the installation site is clear of personnel before hoisting the node. If possible, block off walkway below the hoisting area to prevent pedestrian traffic during hoisting.
Failure to observe these admonishments can result in serious injury or
death.
1 Check the strand size. The minimum strand diameter should be 5/16 inch.
2 Attach the strand clamp brackets to the housing in the position shown in the following illustration. Use a torque wrench tightens the strand clamp bracket bolts from 5 ft-lb to 8 ft-lbs (6.8 to 10.8 Nm).
69
Chapter 3 Installation
70
3 Loosen the strand clamp bolts to separate the clamps enough to insert the strand, but do not remove them. Then lift the housing into proper position on the strand.
4 Slip the clamps over the strand and finger-tighten the clamp bolts. This allows additional side-to-side movement of the housing as needed.
5 Move the housing as needed to install the coaxial cable and connectors. See the illustrations below for an example
Powered from Left
Powered from Right
Strand Mounting the Node
Note: If supplying power to the node through a main output port, a power inserter must be installed to inject the AC voltage onto the RF signal.
6 Use a torque wrench and a 1/2-inch socket to tighten the strand clamp bolts from 5 ft-lb to 8 ft-lbs (6.8 to 10.8 Nm).
Note: A slight tilt of the face of the housing is normal. Cable tension will cause the housing to hang more closely to vertical.
7 Connect the coaxial cable to the pin connector according to the pin connector manufacturer’s specifications.
8 Continue to Fiber Optic Cable Installation (on page 74) and RF Cable
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Chapter 3 Installation
Pedestal or Wall Mounting the Node
Description
Two mounting holes on the housing allow pedestal or wall mounting.
72
Procedure
Follow this procedure for pedestal or wall mounting.
WARNING:
Be aware of the size and weight of the node while mounting. A fully loaded 1.2 GHz GS7000 Node weighs over 50 lbs (22.7 kg).
Ensure that proper handling/lifting techniques are employed when working in confined spaces with heavy equipment.
Failure to observe these admonishments can result in serious injury or
death.
1 Remove the cover of the pedestal.
2 Remove the self-tapping bolts from the strand clamps, if previously installed,
Pedestal or Wall Mounting the Node
and set the bolts and strand clamps aside.
3 Position the 1.2 GHz GS7000 Node horizontally in the enclosure and allow for free flow of air around it. Inadequate airflow could cause the node to exceed thermal parameters. Line up the bolt holes on the bottom of the housing with the mounting holes on the pedestal bracket provided by the pedestal manufacturer.
Important: The node housing must be mounted horizontally, as shown, to ensure proper airflow over the housing cooling fins. Do NOT mount the node housing vertically.
4 Secure the node housing to the pedestal bracket using the strand clamp bracket bolts you removed in step 2. Insert the bolts into the mounting holes. Use the strand clamps as spacers if necessary. Torque the bolts from 8 ft-lb to 10 ft-lb
(10.8 Nm to 13.6 Nm).
5 Connect the coaxial cable to the pin connector according to connector manufacturer’s specifications.
6 Ground the equipment in accordance with local codes and regulations.
7 Continue to Fiber Optic Cable Installation (on page 74) and RF Cable
73
Chapter 3 Installation
Fiber Optic Cable Installation
Overview
The 1.2 GHz GS7000 Node can accept a fiber optic cable connector from either the right or left side of the housing, or both. The fiber optic cable(s) carries forward and reverse optical signals.
This procedure assumes a specific type of connector as an example. Your connector may be different from the one shown in these illustrations. Be sure to install the connector according to the connector manufacturer’s instructions.
Important: Fiber optic cable installation is a critical procedure. Incorrect installation can result in severely degraded 1.2 GHz GS7000 Node performance. Be sure to carefully follow fiber connector manufacturer’s instructions. See Care and Cleaning
of Optical Connectors (on page 134).
Color Code
Fiber connectors and adapters are labeled with the following color code.
Note: This is only a suggested setup. Your fiber assignment may be different. Refer to your network diagrams to verify your color code.
Fiber Color Code Connects to
6
7
4
5
2
3
Connector/Adapter
Number
1
8
Blue
Orange
Green
Brown
Slate
White
Red
Black forward receiver 1 forward receiver 2 reverse transmitter 1 reverse transmitter 2 spare spare spare spare
74
Fiber Optic Cable Installation
Fiber Management System
The fiber management system is made up of a fiber tray and a fiber routing track.
The fiber tray provides a convenient location to store excess fiber and up to two
WDM modules in the node. The tray is hinged to allow it to move out of the way during the insertion of the fibers and for installation or replacement of the node power supplies. The fiber routing track provides a channel for routing fiber pigtails to their appropriate optical modules as well as a location to snap in unused fiber connectors for storage.
The following illustration shows the design of the fiber tray.
Note: Fibers are spooled in a counterclockwise direction in the tray.
The following illustrations show the location and layout of the fiber tray and track in the housing lid.
75
Chapter 3 Installation
76
Fiber Optic Cable Installation
Note: Power supplies are removed in the previous illustration for clarity.
Procedure
Install fiber optic cable as described below.
WARNING:
Laser light hazard. The laser light source on this product emits invisible laser radiation. Avoid direct exposure. Never look into the end of an optical fiber or connector. Failure to observe this warning can
result in eye damage or blindness.
Do not apply power to this product if the fiber is unmated or unterminated.
Do not stare into an unmated fiber or at any mirror-like surface that could reflect light that is emitted from an unterminated fiber.
Do not view an activated fiber with optical instruments.
1 The first step depends on whether the fiber optic cable is factory installed or not.
IF...
fiber optic cable is factory installed
THEN...
splice fiber pigtail of optical fiber input cable to your splice enclosure and continue to RF Cable Installation. fiber optic cable is not installed go to step 2.
2 Select the right or left fiber connection port for use and remove its sealing plug.
77
Chapter 3 Installation
3 Push in the two release tabs at the top of the fiber tray and swivel the top of the fiber tray up and back to allow a clear view of the fiber routing channel below.
78
4 One at a time, carefully insert fibers with attached connectors through the fiber connection port, the fiber channel, and then up and through the fiber entry point in the bottom of the fiber tray. Do not bend or kink fibers. Though not necessary, you can also remove the power supplies and open the fiber routing channel cover for additional access.
Fiber Optic Cable Installation
Note: If using the alternate (right-side) fiber connection port, you have to route the fibers through the fiber channel in the fiber track located underneath the
79
Chapter 3 Installation
unused fiber holders.
5 Hold the connector body to prevent rotation of the connector or fibers.
6 Carefully thread the 5/8-inch threaded nut into the threaded hole of the fiber port. Tighten to 20 to 25 ft-lbs (27.1 to 33.9 Nm).
7 Firmly tighten the rotational nut against the 5/8-inch threaded nut.
8 Push heat shrink tubing over the connector and fiber port and shrink in place.
9 Identify individual fibers according to their color code and determine to which receiver or transmitter module each fiber will connect.
10 Pivot the fiber tray back down and snap it into place on top of the power supply with its locking tabs.
11 Open the fiber tray cover and carefully wind the fibers around the spool in a counterclockwise direction. Be sure to leave enough fiber so that each connector can reach its intended module. Note that different diameter spool paths are provided to properly adjust the fiber length.
80
Fiber Optic Cable Installation
12 Route each fiber to its intended module through the fiber track as shown.
13 Before connection, carefully clean the optical connectors on both fiber and module according to the procedures in Care and Cleaning of Optical Connectors
14 Open the receiver or transmitter module fiber connector cover. Carefully slide the fiber connector into the module connector until it clicks.
15 Repeat steps 12 and 13 for each receiver and transmitter module.
16 Splice fiber pigtail of optical fiber input cable to your splice enclosure.
17 Continue to RF Cable Installation (on page 82).
81
Chapter 3 Installation
RF Cable Installation
Overview
The 1.2 GHz GS7000 Node can accept up to six RF cables. These cables carry forward path RF signal outputs and reverse path RF signal inputs. The RF cables also supply the 45 to 90 V AC power input.
Trimming the Center Conductor
The 1.2 GHz GS7000 Node requires pin-type connectors for all RF connections.
Standard pin connectors, with pins extending 1.5 in. to 1.6 in. (3.8 cm to 4.064 cm) from connector shoulder, require no trimming. You must trim longer pins before inserting them into the housing.
Trimming Using the Integrated Cradle
To trim long pins using the integrated cradle, follow these steps.
1 Place the connector on the cradle as shown in the following illustration.
82
RF Cable Installation
2 If the center conductor extends past the CUT stanchion on the housing, trim the pin flush with the end of the CUT stanchion.
3 Remove any burrs or sharp edges from the trimmed end of the pin.
Trimming Using the Strip Line Mark
To trim long pins using the strip line mark on the housing, follow these steps.
1 Place the connector above the entry port so that it lines up with its installed position.
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Chapter 3 Installation
84
2 If the center conductor extends past the STRIP line on the housing, trim the pin flush with the STRIP line.
3 Remove any burrs or sharp edges from the trimmed end of the pin.
Connecting the RF Cables to the Node Housing
Follow these steps to connect the RF cables.
1 Determine which ports receive an RF cable for your configuration.
2 The length of the RF connector center pin is critical to proper operation. The pin length must be 1.6 inches (4.064 cm). Trim pin if necessary before installation. See
Trimming the Center Conductor (on page 82).
Note: Assemble each RF connector to its cable according to manufacturer’s instructions.
3 Remove the sealing plug of each port to which cables connect. Note that Ports 1,
3, 4, and 6 have the option of a vertical or horizontal connection.
4 Insert the appropriate coaxial connector of each RF cable to the desired housing port and torque to the manufacturer’s specification. Do not exceed recommended torque.
5 Repeat steps 2 through 4 for each RF port used.
6 Continue to Applying Power to the Node.
Applying Power to the Node
Applying Power to the Node
Overview
The 1.2 GHz GS7000 Node requires input power of 45 to 90 V AC from an external power source. This power is supplied through one or more of the RF cables.
The powering configuration is flexible and can be changed to meet most network requirements. Power direction is configured by installing AC shunts for the ports through which you want to pass AC power. An AC segmentable shunt is provided to configure power direction between the two sides of the node.
The following schematic diagram illustrates 1.2 GHz GS7000 Node powering.
Node Powering Procedure
Follow these steps to apply power.
1 Determine which of the RF cables carry 45 to 90 V AC input power.
2 Install shunts in the locations that correspond to the AC-powered RF ports. Each port’s shunt is located on the RF amplifier module near the port as shown in the following illustration.
85
Chapter 3 Installation
4-Way RF Amplifier Module
86
Note: Shunts are available with both red and black tops. Use red to indicate that power is applied to that port. Use black to indicate that input power is not applied.
3 If desired, remove shunts to block AC power at the individual ports.
4 The next step depends on the power path, as follows:
IF...
power will pass from left side of housing (Ports 1,
2, and 3) to right side of housing (Ports 4, 5, and 6)
THEN...
ensure that the AC segmentable shunt is installed. power is to be blocked between left side of housing
(Ports 1, 2, and 3) and right side of housing (Ports
4, 5 and 6) ensure that the AC segmentable shunt is removed.
Ports 1, 2, and 3 are powered from one source and
Ports 4, 5 and 6 are powered from another source
5 Continue to Voltage Check Procedure. ensure that the AC segmentable shunt is removed.
Voltage Check Procedure
Always check both AC and DC voltages during initial setup of the 1.2 GHz GS7000
Node.
Follow these steps to check AC and DC voltages.
Applying Power to the Node
1 Use a true-rms DVM to check for 45 to 90 V AC input voltage at the AC test point on the power supply module.
2 Check for the various DC output voltages (+24.5, +8.5, -6.0, and +5.5) of the power supply at the DC test points on the power supply module.
3 Verify that the Power ON LED on the receiver module is on.
4 Carefully close the housing lid. See Opening and Closing the Housing (on page
87
4
Chapter 4
Setup and Operation
Introduction
This chapter describes how to set up and operate the 1.2 GHz GS7000
Node. These procedures assume the 1.2 GHz GS7000 Node is installed according to the procedures in Chapter 3 of this manual.
Network Requirements
Refer to your network design diagrams during setup. The design diagrams should specify the exact input and output signal levels required for your network. The 1.2 GHz GS7000 Node is configured to have a specific amount of gain at 18 dB of linear tilt from 52 MHz to
1218 MHz.
In This Chapter
Tools and Test Equipment ................................................................... 90
Forward Path Setup Procedure ........................................................... 97
Reverse Path Setup Procedure .......................................................... 101
Reconfiguring Forward Signal Routing........................................... 103
Reconfiguring Reverse Signal Routing ............................................ 113
89
Chapter 4 Setup and Operation
Tools and Test Equipment
Required Tools and Test Equipment
Tools and test equipment required for setup are listed below. Equivalent items may be substituted. Ensure test equipment is calibrated and in good working order.
Fluke Model 77 (or equivalent) true-rms digital voltmeter (DVM) with 0.001 resolution.
Signal generator capable of generating carriers at 55.25 MHz and 1.2GHz
“F” barrel adapter – 1.2 GHz
Field strength meter capable of measuring up to 1.2GHz
Field sweep receiver/transmitter with a minimum bandwidth of 1.2 GHz
EXFO FOT 22AX optical power meter with adapters
Fiber optic jumper to test transmitter optical output power
Glendale Technologies optical eye protection blocking 900–1600 nm light
90
System Diagrams
System Diagrams
External
-20 dB TP
Functional Diagrams: 4-Way Forward Segmentable Node
The following diagrams show the signal flow through the 4-way forward segmentable node.
Non-Segmented
-20 dB
Fwd. TP
RF Switch RF Switch
P1
AC
Byp ass
Power Director
FWD
REV
EQ Pad
Pad Pad
Pad EQ FWD
REV
-20 dB
Rev. TP
Pad Pad
-20 dB
Rev. TP
Thermal
External
-20 dB TP
AC
Byp ass
Power Director
P4
Thermal
External
-20 dB TP
P2
External
-20 dB TP
P3
-20 dB
Fwd. TP Node
Signal Director
Jumper
RF Switch
AC
Byp ass
Power Director
-20 dB
Rev. TP
FWD
REV
Pad
EQ Pad
Crowbar
AC
Byp ass
Power Director
-20 dB
Fwd. TP
-20 dB
Rev. TP
Pad
Aux. Reverse Injection
Director
(to RCM)
5
-210 MHz
Reverse Injection
Option
1x4
Forward Configuration
Module
Pad
Thermal
Pad
Thermal
RF Switch
Pad EQ
RS RS RS
Pad
RS
RS = reverse switch
Aux. Rev
RF
Injection
FWD
REV
Node
Signal Director
Splitter
-20 dB
Rev. TP
4x1 Reverse
Configuration Module w/Aux Reverse
RF Injection
(to RCM)
5
-210 MHz
Reverse Injection
Option
Pad
Aux. Reverse Injection
Director
-20 dB
Rev. TP
External
-20 dB TP
AC
Byp ass
Power Director
P5
Crowbar
External
-20 dB TP
AC
Byp ass
Power Director
P6
F1
Power
Supply #2
Power
Supply #1
Fiber Tray
Pad Pad Pad
RCVR
# 1
Pad
Optical
Interface Board
Pad
Pad
XMT R
# 1
Pad Pad Pad
P
P
TP
F2
91
Chapter 4 Setup and Operation
Left-Right Segmented
92
System Diagrams
External
-20 dB TP
Fully Segmented
-20 dB
Fwd. TP
P1
AC
Byp ass
Power Director
-20 dB
Rev. TP
FWD
REV
Pad
EQ Pad
RF Switch
External
-20 dB TP
P2
External
-20 dB TP
P3
-20 dB
Fwd. TP Node
Signal Director
Jumper
RF Switch
AC
Byp ass
Power Director
-20 dB
Rev. TP
FWD
REV
EQ Pad
Pad
Crowbar
AC
Byp ass
Power Director
-20 dB
Fwd. TP
-20 dB
Rev. TP
Pad
Aux. Reverse Injection
Director
(to RCM)
5
-210 MHz
Reverse Injection
Option
4x4
Forward Configuration
Module
Pad
Thermal
Pad Pad
Thermal
Thermal
RF Switch
Pad EQ
Pad
FWD
REV
-20 dB
Rev. TP
External
-20 dB TP
AC
Byp ass
Power Director
P4
Pad
Thermal
Aux. Rev
RF
Injection
RF Switch
Pad EQ
RS
RS RS
RS
Pad
RS = reverse switch
FWD
REV
Node
Signal Director
Splitter
-20 dB
Rev. TP
AC
Byp ass
Power Director
Ext ernal
-20 dB TP
P5
4x4 Reverse
Configuration Module w/Aux Reverse
RF Injection
(to RCM)
5
-210 MHz
Reverse Injection
Option
Pad
Aux. Reverse Injection
Director
-20 dB
Rev. TP
Crowbar
Ext ernal
-20 dB TP
AC
Byp ass
Power Director
P6
F1
Power
Supply #2
Power
Supply #1
Fiber Tray
RCVR
# 4
Pad Pad
RCVR
# 3
RCVR
# 2
Pad
RCVR
# 1
Pad
Optical
Interface Board
Pad
Pad
XMT R
# 1
Pad
XMT R
# 2
Pad
XMT R
# 3
Pad
XMT R
# 4
P P P P
P P P P
TP TP TP TP
F2
93
Chapter 4 Setup and Operation
Functional Diagram: Hub Node
The following diagram shows the signal flow through a 4-way non-segmented hub node.
94
System Diagrams
RF Assembly
Become familiar with the function and component layout of the RF assembly before aligning the 1.2 GHz GS7000 Node. The cover of the RF assembly is printed with a diagram that shows the functional signal flow and identifies each field-replaceable component.
Some of these components (pads, equalizers, and node signal directors) are removed and replaced with different value components during the setup procedures.
4-Way Forward Segmentable Node RF Assembly
The following illustrations show the 4-way forward segmentable node RF assembly.
Left side Ports 1, 2, and 3 illustration.
95
Chapter 4 Setup and Operation
Right side Ports 4, 5, and 6 illustration.
96
Forward Path Setup Procedure
Forward Path Setup Procedure
Introduction
This procedure describes how to perform the forward path setup.
Note: The procedure uses an example with a transmitter modulation index of 2.5% per channel and the 1.2GHz node with RF output level of 54 dBmV @ 1218 MHz.
Setup Procedure
Perform the following steps to set up the forward path.
1 Ensure all unused RF ports are terminated with 75 ohms. Use an AC load if AC is routed to the RF port.
2 Open the housing according to Opening and Closing the Housing (on page 122).
3 Carefully disconnect the forward path optical fiber(s), if connected.
WARNING:
Laser hazard. This product contains a class 3B laser with no safety interlocks.
Under no circumstances should connectors be viewed with equipment enabled. Direct viewing of connectors can cause eye damage. Failure to adhere to this admonishment may result in serious injury to the eye(s) or even
blindness.
CAUTION:
Disconnecting the optical fibers of a working network element will interrupt
customer service.
Note: Ensure all optical connectors are clean. See Care and Cleaning of Optical
4 Use an optical power meter to measure the level of the input light signal from the forward path optical fiber cable(s). Signal should be 0 dBm, 1mW, nominal. For a standard receiver, record the measurement(s).
5 Connect the forward path optical fiber(s) to the receiver. Use a DVM to measure
DC voltage at receiver optical power level test point. Scale: 1V DC = 1mW (1310 nm transmitter) and 1.12 V DC = 1mW (1550 nm transmitter).
97
Chapter 4 Setup and Operation
98
6 Set the receiver module attenuator switch as follows:
Standard Receiver
IF received optical power is...
—2 to +2 dBm
THEN set the attenuator switch to...
-8 dB
-6 to -2 dBm
Low Input Receiver -6 to -2 dBm
0 dB
-8 dB
-10 to -6 dBm 0 dB
7 For standard input receiver, check the RF level at the -20 dB RF test point on each forward path receiver. Signal level should be +7 dBmV at the test point with 0 dBm optical input power and 2.5% index modulation of the laser headend transmitter. (With optical receiver attenuator set to the -8 dB switch setting.) This represents an optical receiver output of +27 dBmV. For low input receiver follow the same process to check the RF level and refer the table below.
For standard receiver For low input receiver Att/OMI
Output level 27dBmV 27dBmV 8 dB/2.5%
8 dB/2.5% Input optical power
0dBm -4dBm
8 The next step depends on your RF output levels.
IF your RF output ports will... and you have... THEN...
Forward Path Setup Procedure
all have equal output levels 1X, 2X, or 4X segmentation Go to step 9. be driven at different levels 4X segmentation Go to step 10. be driven at different levels 1X or 2X segmentation Go to step 11.
9 If all four of the node's output ports are to have equal output levels, re-balancing of the RF level should not be required for 4-way segmentation.
To achieve an output level of 54 dBmV @1218MHz / 50.7 dBmV @ 1002 MHz
- with 27 dbmV output from the optical receiver, install a 15 dB attenuator pad into the optical interface board just above the receiver module.
Go to step 14.
10 If using 4-way segmentation, all four of the node's output ports can be set to have un-equal output levels. Re-balancing of the RF level should not be required for 4-way segmentation.
11 Example: To achieve an output level of 54 dBmV @1218MHz / 50.7 dBmV @
1002 MHz at output port 1
- with 27 dBmV output from the optical receiver, install a 15 dB attenuator pad into the optical interface board just above the optical receiver 3 module.
To achieve an output level of 55 dBmV @1218MHz / 51.7 dBmV @ 1002 MHz at output port 2
- with 27 dBmV output from the optical receiver, install a 14dB attenuator pad into the optical interface board just above the optical receiver 4 module.
Repeat this process to obtain the desired output levels for all remaining output ports.
Go to step 14.
12 If the node's output RF ports are to be driven at different levels, and the node is not set up in 4-way forward segmentation, the port with the highest output level should be used to set up the node. Measure signal level at the forward RF test point, on the amplifier module, to identify the port with the highest level output signal. Verify the output power level is correct using the OIB Pad as in Step 9.
Go to step 13.
13 Increase the attenuator pad value at the FWD PORT OUT PAD locations on the
RF amplifier module to reduce the output level of the ports which need to be driven at a lower level than the port used to setup the node. See Appendix A -
Technical Information for pad selection charts.
14 The GS7000 Node is set for 18 dB of linear tilt between 54 and 1218 MHz / 14.7 dB between 54 MHz and 1002 MHz.
4-Way Forward Segmentable RF Amplifier Note: Four 18.0 dB linear field replaceable equalizers are installed in the node at the factory, one each on the four independent forward amplification paths. This achieves 18.0 dB of linear tilt between 54 MHz and 1218 MHz (14.7 dB between 54 MHz and 1002 MHz).
99
Chapter 4 Setup and Operation
If your network requires a different value, remove the field replaceable 18 dB equalizers and replace with equalizers of the appropriate value. See Forward
Equalizer Chart (on page 156).
15 Continue to Reverse Path Setup Procedure or close the housing according to
Opening and Closing the Housing (on page 122).
100
Reverse Path Setup Procedure
Reverse Path Setup Procedure
Introduction
This procedure describes how to perform the reverse path setup. Perform this procedure only if your 1.2 GHz GS7000 Node has an active reverse path.
Optical Transmitter Setup Procedure
Perform the following steps to set up the proper level into the reverse path optical transmitters.
1 Open the housing according to Opening and Closing the Housing (on page 122).
2 Verify the level of the input reverse RF signals at the RF test points located near the main ports of the RF amp module. Nominal level is +17 dBmV per channel.
Install the appropriate value input pad at the REV PORT IN PAD location to attenuate the signal to the desired level for the reverse path of the node.
3 With the input to the node port set to 17 dBmV per channel, a 4 dB transmitter input attenuator pad should be installed on the optical interface board (just above the transmitter module) to achieve 13 dBmV level into the optical transmitter (-7 dBmV at the transmitter -20 dB test point). This RF input level into the high gain reverse transmitter will achieve an optical modulation index
(OMI) of 10%.
4 Repeat steps 2 and 3 for each RF port carrying a reverse path signal.
5 Use an optical power meter to measure the transmitter optical output power.
(1330 nm or 1550 nm)
101
Chapter 4 Setup and Operation
102
6 Using a DVM, measure the DC voltage at the optical test point and record the value.
7 Check the connection of the optical connector. Make sure the optical connector is seated and verify that the fiber bend radius is greater than 1 inch.
WARNING:
When handling optical fibers always follow laser safety precautions.
Reconfiguring Forward Signal Routing
Reconfiguring Forward Signal Routing
Introduction
This section describes how to configure the forward signal routing of the 1.2 GHz
GS7000 Node.
Forward Routing Configurations
The receiver modules and the forward configuration module determine the forward signal routing. Each module must be in its proper slot to achieve the different node configurations.
The following table shows the required modules and their slot locations for various node configurations.
If the configuration is…
one receiver, four outputs one receiver, four outputs
(with external RF source) two receivers, four outputs, redundant two receivers, four outputs, redundant (with external
RF source) two receivers, each feeding two outputs, 2-way segmented four receivers, each pair feeding two outputs, 2-way segmented, redundant three receivers, four outputs three receivers, four outputs
Then use configuration module…
1x4 Forward
1x4 Forward with Forward RF
Injection, plus FLI module
1x4 Redundant Forward, plus
SM/LCM
1x4 Redundant Forward with Forward
RF Injection, plus SM/LCM and FLI module
2x4 Forward
2x4 Redundant Forward, plus
SM/LCM
Install Receivers in
Positions...
1
1
1, 2
1, 2
1, 3
1, 2, 3, 4
3x4 Forward (for receivers 1, 3, and 4) 1, 3, 4
3x4 Forward (for receivers 1, 2, and 4) 1, 2, 4
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Chapter 4 Setup and Operation
If the configuration is… Then use configuration module…
four receivers, each feeding separate outputs
4x4 Forward
1x4 Forward Configuration Modules
A single forward receiver (RCVR 1) feeds all RF output ports.
Install the receiver in RCVR 1.
4-way forward segmentable node
Install Receivers in
Positions...
1, 2, 3, 4
104
The following diagram illustrates forward path signal flow in this configuration module.
Reconfiguring Forward Signal Routing
1x4 Forward Configuration Modules with Forward RF Injection
A single forward receiver (RCVR 1) feeds all RF output ports. The Forward Local
Injection (FLI) Module routes an RF signal from an external source to the Forward
Configuration Module which is then coupled with the input from RCVR 1.
Install the receiver in RCVR 1. Install the FLI Module in the RCVR 4 position.
4-way forward segmentable node
The following diagram illustrates forward path signal flow in this configuration module.
105
Chapter 4 Setup and Operation
1x4 Redundant Forward Configuration Modules
A primary receiver (RCVR 1) and a redundant receiver (RCVR 2) feed all RF output ports.
The Status Monitor/Local Control Module automatically switches from primary receiver to redundant receiver when it senses a loss of optical input to the primary receiver. Once optical input is restored, the system automatically switches back to the primary receiver.
Install the primary receiver in RCVR 1 and the redundant receiver in RCVR 2.
4-way forward segmentable node
106
The following diagram illustrates forward path signal flow in this configuration module.
Reconfiguring Forward Signal Routing
1x4 Redundant Forward Configuration Modules with Forward RF
Injection
A primary receiver (RCVR 1) and a redundant receiver (RCVR 2) feed all RF output ports. The FLI Module routes an RF signal from an external source to the Forward
Configuration Module which is then coupled with the input from RCVR 1/2.
The Status Monitor/Local Control Module automatically switches from primary receiver to redundant receiver when it senses a loss of optical input to the primary receiver. Once optical input is restored, the system automatically switches back to the primary receiver.
Install the primary receiver in RCVR 1 and the redundant receiver in RCVR 2. Install the FLI module in the RCVR 4 position. When using this module remove the 0.5dB forward interstage attenuator pads and replace with 0dB attenuator pads.
4-way forward segmentable node
The following diagram illustrates forward path signal flow in this configuration module.
107
Chapter 4 Setup and Operation
2x4 Forward Configuration Modules
Two receivers (RCVR 1 and RCVR 3) each feed 2/3 output ports.
The first receiver (RCVR 1) feeds the right side of the amplifier (Ports 4 and 5/6). The second receiver (RCVR 3) feeds the left side of the amplifier (Ports 1 and 2/3).
Install the first primary receiver in RCVR 1. Install the second primary receiver in
RCVR 3.
4-way forward segmentable node
108
The following diagram illustrates forward path signal flow in this configuration module.
Reconfiguring Forward Signal Routing
2x4 Redundant Forward Configuration Modules
Two primary receivers (RCVR 1 and RCVR 3) and two redundant receivers (RCVR 2 and RCVR 4) each pair feed 2/3 output ports.
The first pair of primary (RCVR 1) and redundant (RCVR 2) receivers feeds the right side of the amplifier (Ports 4 and 5/6). The second pair of primary (RCVR 3) and redundant (RCVR 4) receivers feeds the left side of the amplifier (Ports 1 and 2/3).
The Status Monitor/Local Control Module switches between primary and redundant receivers upon loss of optical input to a primary receiver, and switches back to the paired primary when optical input is restored.
Install the first set of receivers as follows:
first primary receiver RCVR 1
first redundant receiver RCVR 2
Install the second set of receivers as follows:
second primary receiver RCVR 3
second redundant receiver RCVR 4
4-way forward segmentable node
The following diagram illustrates forward path signal flow in this module.
109
Chapter 4 Setup and Operation
3x4-1, 3, 4 Forward Configuration Module
Three receivers each feeding one/two/three/four RF output ports. RCVR 1 feeds
Ports 4/5/6. RCVR 3 feeds Port 1. RCVR 4 feeds Ports 2/3.
Note: The 3x4-1, 3, 4 FCM can only be used with the 4-way RF amplifier module.
110
The following diagram illustrates forward path signal flow in this module.
Reconfiguring Forward Signal Routing
3x4-1, 2, 4 Forward Configuration Module
Three receivers each feeding one/two/three/four RF output ports. RCVR 1 feeds
Ports 5/6. RCVR 2 feeds Port 4. RCVR 4 feeds Ports 1/2/3.
Note: The 3x4-1, 2, 4 FCM can only be used with the 4-way RF amplifier module.
The following diagram illustrates forward path signal flow in this module.
111
Chapter 4 Setup and Operation
4x4 Forward Configuration Module
Four receivers each feed separate RF outputs. RCVR 1 feeds Ports 5/6. RCVR 2 feeds
Port 4. RCVR 3 feeds Port 1. RCVR 4 feeds Ports 2/3.
Note: The 4x4 FCM can only be used with the 4-way RF amplifier module.
112
The following diagram illustrates forward path signal flow in this module.
Reconfiguring Reverse Signal Routing
Reconfiguring Reverse Signal Routing
Introduction
This section describes how to configure the reverse signal routing of the 1.2 GHz
GS7000 Node.
Reverse Routing Configurations
The transmitter modules and the reverse configuration module determine the reverse signal routing. Each module must be in its proper slot to achieve the different node configurations.
The following table shows the required modules and their slot locations for various node configurations.
If the configuration is…
four inputs, one transmitter
(optional external RF source) four inputs, all feeding two transmitters, redundant four inputs, each pair of inputs feeding a transmitter, 2-way segmented (optional external RF source) four inputs, two feeding separate transmitters, two feeding a single transmitter
(optional external RF source) four inputs, two feeding separate transmitters, two feeding a single transmitter
(optional external RF source) four inputs, each pair of inputs feeding two transmitters, 2-way segmented, redundant four inputs, each feeding a separate transmitter, 4-way segmented (optional external RF source)
Then use configuration module…
4x1 Reverse with Auxiliary
Reverse Injection
4x1 Redundant Reverse
4x2 Reverse with Auxiliary
Reverse Injection
4x3 Reverse with Auxiliary
Reverse Injection
(left combined, right segmented)
4x3 Reverse with Auxiliary
Reverse Injection
(left segmented, right combined)
4x2 Redundant Reverse
4x4 Reverse with Auxiliary
Reverse Injection
Install Transmitters in Positions...
1
1, 2
1, 3
1, 3, 4
1, 2, 4
1, 2, 3, 4
1, 2, 3, 4
113
Chapter 4 Setup and Operation
4x1 Reverse Configuration Module with Auxiliary Reverse RF Injection
All four ports are combined to a single reverse transmitter. An RF signal from an external source can optionally be injected and coupled with the reverse RF inputs on
Ports 3/6 and routed to Transmitter 1.
Install the transmitter module in XMTR 1.
114
The following diagram illustrates reverse path signal flow in this configuration module.
Reconfiguring Reverse Signal Routing
4x1 Redundant Reverse Configuration Module
All four ports are combined and the signal is split to two reverse transmitters. This allows you to have redundant transmitters.
Install the transmitters in XMTR 1 and XMTR 2.
The following diagram illustrates reverse path signal flow in this configuration module.
115
Chapter 4 Setup and Operation
4x2 Reverse Configuration Module with Auxiliary Reverse RF Injection
Signals from the left side of the amplifier (Ports 1 and 2/3) are combined and routed to a transmitter (XMTR 1). Signals from the right side of the amplifier (Ports 4 and
5/6) are combined and routed to a different reverse transmitter (XMTR 3). An RF signal from an external source can optionally be injected and coupled with the reverse RF inputs from Ports 3/6 and routed to Transmitter 1.
Install the transmitter that is dedicated to Ports 1 and 2/3 in XMTR 1.
Install the transmitter that is dedicated to Ports 4 and 5/6 in XMTR 3.
116
The following diagram illustrates reverse path signal flow in this configuration module.
Reconfiguring Reverse Signal Routing
4x2 Redundant Reverse Configuration Module
Signals from the left side of the amplifier (Ports 1 and 2/3) are combined and then split evenly to feed two reverse transmitters (XMTR 1 and XMTR 2). Signals from the right side of the amplifier (Ports 4 and 5/6) are combined and then split evenly to feed two reverse transmitters (XMTR 3 and XMTR 4).
Install the transmitters that are dedicated to Ports 1 and 2/3 in XMTR 1 and XMTR 2.
Install the transmitters that are dedicated to Ports 4 and 5/6 in XMTR 3 and XMTR 4.
The following diagram illustrates reverse path signal flow in this configuration module.
117
Chapter 4 Setup and Operation
4x3-1, 2, 4 Reverse Configuration Module with Auxiliary Reverse RF
Injection
Signals from the right side of the amplifier (Ports 4 and 5/6) are combined and routed to a reverse transmitter (XMTR 4). Signals from Port 1 are routed to XMTR 1.
Signals from Ports 2/3 are routed to XMTR 2. An RF signal from an external source can optionally be injected at Ports 3/6 and coupled with the reverse RF input from
Port 1 and routed to XMTR 1.
Install modules as follows:
Transmitter dedicated to Port 1 in XMTR 1
Transmitter dedicated to Port 2/3 in XMTR 2
Transmitter dedicated to Port 4/5/6 in XMTR 4
118
The following diagram illustrates reverse path signal flow in this module.
Reconfiguring Reverse Signal Routing
4x3-1, 3, 4 Reverse Configuration Module with Auxiliary Reverse RF
Injection
Signals from the left side of the amplifier (Ports 1 and 2/3) are combined and routed to a reverse transmitter (XMTR 1). Signals from Port 4 are routed to XMTR 3. Signals from Ports 5/6 are routed to XMTR 4. An RF signal from an external source can optionally be injected at Ports 3/6 and coupled with the reverse RF inputs from
Ports 2/3 and 1 and routed to XMTR 1.
Install modules as follows:
Transmitter dedicated to Ports 1/2/3 in XMTR 1
Transmitter dedicated to Port 4 in XMTR 3
Transmitter dedicated to Port 5/6 in XMTR 4
The following diagram illustrates reverse path signal flow in this module.
119
Chapter 4 Setup and Operation
4x4 Reverse Configuration Module with Auxiliary Reverse RF Injection
A signal from each port is assigned to a dedicated reverse transmitter. An RF signal from an external source can optionally be injected and coupled with the reverse RF inputs from Ports 3/6 and routed to Transmitter 1.
Note: This module is typically used when using multiplexing digital reverse modules, such as our EDR Digital Reverse Modules. Since the digital reverse module occupies the physical space that transmitters 3 and 4 used to occupy in the node lid, only a 6-port optical interface board can be used.
Install modules as follows:
Transmitter dedicated to Port 1 in XMTR 1
Transmitter dedicated to Port 2/3 in XMTR 2
Transmitter dedicated to Port 4 in XMTR 3
Transmitter dedicated to Port 5/6 in XMTR 4
120
The following diagram illustrates reverse path signal flow in this module.
5
Chapter 5
Maintenance
Introduction
This section describes maintenance procedures for the 1.2 GHz GS7000
Node.
In This Chapter
Opening and Closing the Housing ................................................... 122
Preventative Maintenance ................................................................. 124
Removing and Replacing Modules .................................................. 127
Care and Cleaning of Optical Connectors ....................................... 134
121
Chapter 5 Maintenance
Opening and Closing the Housing
Overview
Installation or maintenance of the 1.2 GHz GS7000 Node requires opening the housing to access the internal modules.
Proper housing closure is important to maintaining the node in good working condition. Proper closure ensures a good seal against the environment, protecting the internal modules.
Opening the Housing
Open the housing as follows.
1 Remove the bolts securing the lid to the base.
2 Carefully open the lid to allow access to the inside of the housing.
3 Inspect gaskets on the cover flange and on the test port plugs.
4 Replace any gaskets showing signs of wear (cracked, twisted, pinched, or dry) with new, silicon-lubricated gaskets.
Closing the Housing
Close the housing as follows.
1 Ensure any worn gaskets are replaced, and the gaskets are clean and in the correct position.
2 Carefully close the lid.
CAUTION:
Use caution when closing housing. Improper closing may result in the unit
not being sealed from the environment.
3 For strand-mounted housings, pull the lid away from the base and remove the slack from the hinge before rotating the lid up toward the base.
4 Ensure no cables are pinched between lid and base.
5 Secure lid to base with bolts. Tighten from 5 to 12 ft-lbs (6.8 to 16.3 Nm) in the sequence shown in the following illustration. Repeat the sequence twice, ending with the final torque specification.
122
Opening and Closing the Housing
123
Chapter 5 Maintenance
Preventative Maintenance
Overview
Preventive maintenance procedures are regularly scheduled actions that help prevent failures and maintain the appearance of the equipment.
Schedule
Perform the preventive maintenance procedures at these intervals.
Procedure
Visual Inspection:
External Surfaces
Connectors
Indicators
Wiring/Cable Assemblies
Cleaning:
External Surfaces
External Controls/Connectors
Internal Connectors/Circuit Cards
Interval
Semiannually
Semiannually
Semiannually
Annually
Annually
Annually
Annually
Visual Inspection
Visually inspect the following items.
What to Inspect
Exterior surfaces
How to Inspect
Inspect for:
dust, dirt, lubricants, or other foreign matter worn spots or deep scratches on surfaces
corrosion
marred protective finish exposing bare metal
missing, incorrect or obliterated marking, decals, or reference designators
124
Preventative Maintenance
What to Inspect
Connectors
Wiring and cables
How to Inspect
Inspect for:
broken, loose, bent, corroded, or missing pins
cracked insulator inserts
Inspect for:
cuts, nicks, burns, or abrasions
exposed bare conductors
sharp bends
pinched or damaged wires
broken or loose lacing or clamps
Cleaning
Clean exterior surfaces of the equipment at least annually.
Consumable Materials
Use the materials listed below (or equivalent) when cleaning the equipment.
Item
Isopropyl alcohol
Cheesecloth
Spray-type contact cleaner
Specification
TT-I-735
CC-C-440
(none)
Procedure
Clean the equipment as described below.
1 Use a small paintbrush to brush dust from connectors.
2 Wipe surfaces dry with clean, dry cheesecloth.
3 Clean exterior surfaces with clean cheesecloth moistened with isopropyl alcohol or general-purpose detergent. Do not let alcohol or detergent get inside equipment or connectors.
125
Chapter 5 Maintenance
WARNING:
Isopropyl alcohol is flammable. Use isopropyl alcohol only in well-ventilated areas away from energized electrical circuits and heated objects such as soldering irons or open flames. Avoid excessive inhalation of vapors or prolonged or repeated contact with skin. Wear industrial rubber gloves and industrial safety goggles to avoid contact with skin. Do not take internally.
Failure to comply with this admonishment can cause injury, physical disorder,
or death.
CAUTION:
Do not use cleaning fluids containing trichloroethylene, trichloroethane, acetone or petroleum-based cleaners on equipment. Failure to comply with
this caution could harm equipment surfaces.
4 Clean electrical contacts with spray-type contact cleaner.
5 Clean internal connectors and circuit boards with hand-controlled, dry-air jet. Do not use pressure exceeding 15 lb/in2 (1.05 kg/cm2, or 103.43 kPa).
6 Clean interior surfaces with clean cheesecloth moistened with isopropyl alcohol or general-purpose detergent.
7 Clean internal electrical contacts with clean cheesecloth moistened with spray-type contact cleaner.
8 Dry interior with clean, dry cheesecloth.
126
Removing and Replacing Modules
Removing and Replacing Modules
Overview
This procedure describes how to remove and replace the internal modules of the 1.2
GHz GS7000 Node. All field-replaceable modules can be removed and replaced without removing power from the 1.2 GHz GS7000 Node.
Field-replaceable modules include:
Forward optical receiver modules
Reverse optical transmitter modules
Optical amplifier modules
Optical switch modules
Status monitor/local control module
Forward configuration module
Reverse configuration module
Equalizers
Node signal directors
Power supply modules
RF amplifier assembly
CAUTION:
Removing power from the 1.2 GHz GS7000 Node will interrupt customer service. Removing any module, except for the status monitor/local control module, will interrupt customer service unless that module has a redundant
backup.
Module Replacement Procedure
Follow this procedure to remove and replace an optical receiver, optical transmitter, optical amplifier, optical switch, status monitor/local control module, or power supply module.
1 Open the housing. See Opening and Closing the Housing (on page 122).
2 Carefully tag and remove any optical fibers from a receiver or transmitter module.
WARNING:
Laser light hazard. Never look into the end of an optical fiber or connector.
Failure to observe this warning can result in eye damage or blindness.
127
Chapter 5 Maintenance
128
3 Loosen the screws securing the module.
4 Lift the module straight up out of the housing to unplug it.
Note: Pull up on the built-in handle on a receiver module, transmitter module, status monitor/local control module, or power supply module.
5 Position the new module in the same location and carefully slide the module into its slot until connected to the optical interface board.
6 Tighten the screws securing the module. Torque screws to 25 to 30 in-lbs (2.8 to
3.4 Nm).
7 Carefully reconnect any optical fibers that were removed from the original module. Clean optical connectors before reconnecting. See Care and Cleaning of
Optical Connectors (on page 134) for cleaning procedure.
WARNING:
Laser light hazard. Never look into the end of an optical fiber or connector.
Failure to observe this warning can result in eye damage or blindness.
8 Close the housing. See Opening and Closing the Housing (on page 122).
Important: If you are using a Local Control Module in the node be sure to press the Auto Set-Up button on the cover of the LCM before you close the node housing. This allows the LCM to check for, and detect, installed modules. If the modules are not detected during this discovery process, they cannot be monitored and controlled by the LCM. The node must be powered and the modules operating properly in order to be detected.
9 Perform the setup procedure in Chapter 4 to verify node performance.
Optical Amplifier and Optical Switch Module Pin Adaptor
Both the EDFA optical amplifier modules and the optical switch module require the use of a pin adaptor to be mounted in the node lid and connected to the optical interface board.
Optical transmitters and optical receivers can only be mounted on their respective sides in the node lid, transmitters on the right and receivers on the left. The pin alignment on these modules is slightly different to prevent accidentally installing a receiver in a transmitter slot or a transmitter in a receiver slot.
Since the optical amplifier and optical switch modules can be mounted on either the left-hand or right-hand side, they require a reversible pin adaptor that can match the pin alignment for either a transmitter or a receiver slot.
Removing and Replacing Modules
The reversible pin adaptor is color coded. One side is blue and the other side is red.
To install the module in a transmitter slot, assemble the pin adaptor on the module with the red side facing outward. To install the module in a receiver slot, assemble the pin adaptor on the module with the blue side facing outward.
The following illustrations show how to assemble the pin adaptor to the module.
CAUTION:
To prevent electrostatic damage to electronic equipment, take ESD
precautions, including the use of an ESD wrist strap.
129
Chapter 5 Maintenance
Accessing the Receiver/Transmitter Module Fiber Spool and Connector
Optical receivers and transmitter modules have an integrated fiber spool inside the module housing. This allows the fiber pigtail to be spooled up and contained within the module housing.
You may need to access this spool to clean or replace a fiber pigtail or connector.
Follow this procedure to access the module fiber spool and connector.
1 Pull up on the two module cover knurled tabs. Use a slight rocking motion.
Note: If the module is out of the housing, it is easier to hold the module in both hands and push up on the two module cover knurled tabs with your thumbs.
You can also insert a flat blade screwdriver into the cover release tab slot on the right side of the module housing to assist with opening the cover.
The module cover opens as shown.
130
2 Pull the fiber connector straight out from the side of the module cover to remove it.
3 Disassemble the fiber connector and pigtail for cleaning if necessary.
Removing and Replacing Modules
4 Reattach the fiber connector to the module cover and close the cover.
Forward/Reverse Configuration Module, Equalizer, and Node Signal
Director Replacement Procedure
The forward and reverse configuration modules, equalizers, and node signal directors plug into the RF amplifier assembly through cut-outs in its cover.
To remove these modules, pull up carefully on their integrated handles until they separate from the RF amplifier assembly.
RF Amplifier Assembly Replacement Procedure
Follow this procedure to remove and replace the RF amplifier assembly.
1 Open the housing. See Opening and Closing the Housing (on page 122).
2 Remove the AC power shunts and make a note of their location for reinstallation in the replacement RF amplifier assembly.
CAUTION:
Damage to the node may result if AC power shunts are not removed before
replacing the RF amplifier assembly.
131
Chapter 5 Maintenance
3 Loosen the seven shoulder screws securing the RF amplifier assembly to the housing.
Note: The screw locations are identified by number, 1 through 7.
4 Insert a flat-blade screwdriver into the small holes in the metal handles on each side of the RF amplifier assembly and pry up carefully to disconnect the RF amplifier assembly’s rear panel connectors.
Important: Be careful not to damage the housing with the screwdriver.
132
5 Grasp the two metal handles on the RF amplifier assembly and carefully lift the
RF assembly out of the housing.
Removing and Replacing Modules
6 To replace the RF amplifier assembly in the housing, carefully align the assembly in the housing, lower it into place and push down to reconnect the rear panel connectors.
7 Secure the RF amplifier assembly to the housing with the seven cross-head shoulder screws.
Important: Tighten the screws in order by number, 1 through 7. Repeat the sequence twice, ending with a torque of 18 to 20 in-lbs (2.0 to 2.25 Nm).
8 Reinstall the AC power shunts in their proper locations on the RF amp assembly.
9 Close the housing. See Opening and Closing the Housing (on page 122).
10 Perform the setup procedure in Chapter 4 to verify node performance.
133
Chapter 5 Maintenance
Care and Cleaning of Optical Connectors
CAUTION:
Proper operation of this equipment requires clean optical fibers. Dirty fibers
will adversely affect performance. Proper cleaning is imperative.
The proper procedure for cleaning optical connectors depends on the connector type.
The following describes general instructions for fiber-optic cleaning. Use your company's established procedures, if any, but also consider the following.
Cleaning fiber-optic connectors can help prevent interconnect problems and aid system performance. When optical connectors are disconnected or reconnected, the fiber surface can become dirty or scratched, reducing system performance.
Inspect connectors prior to mating, clean as needed, and then remove all residues.
Inspect connectors after cleaning to confirm that they are clean and undamaged.
Recommended Equipment
CLETOP or OPTIPOP ferrule cleaner (CLETOP Type A for SC, Type B for LC)
Compressed air (also called “canned air”)
Lint-free wipes moistened with optical-grade (99%) isopropyl alcohol
Bulkhead swabs for LC or SC type connectors (choose appropriate type)
Optical connector scope
Tips for Optimal Fiber-Optic Connector Performance
Do not connect or disconnect optical connectors with optical power present.
Always use compressed air before cleaning the fiber-optic connectors and when cleaning connector end caps.
Always install or leave end caps on connectors when they are not in use.
If you have any degraded signal problems, clean the fiber-optic connector.
Advance a clean portion of the ferrule cleaner reel for each cleaning.
Turn off optical power before making or breaking optical connections to avoid microscopic damage to fiber mating surfaces.
134
Care and Cleaning of Optical Connectors
To Clean Optical Connectors
WARNING:
Avoid personal injury! Use of controls, adjustments, or performance of procedures other than those specified herein may result in hazardous
radiation exposure.
Avoid personal injury! The laser light source on this equipment emits
invisible laser radiation. Avoid direct exposure to the laser light source.
Avoid personal injury! Viewing the laser output with optical instruments
(such as eye loupes, magnifiers, or microscopes) may pose an eye hazard.
Connect or disconnect fiber only when equipment is OFF or in Service mode.
Do not apply power to this equipment if the fiber is unmated or unterminated.
Do not look into an unmated fiber or at any mirror-like surface that could reflect light that is emitted from an unterminated fiber.
Do not view an activated fiber with optical instruments such as eye loupes, magnifiers, or microscopes.
Use safety-approved optical fiber cable to maintain compliance with applicable laser safety requirements.
Connector cleanliness is crucially important for optimum results in fiber optic communications links. Even the smallest amount of foreign material can make it impossible to obtain the expected insertion and return losses. This can reduce the range of the equipment, shorten its expected service life, and possibly prevent the link from initializing at all.
New equipment is supplied with clean optical connectors and bulkheads. Clean these connectors and bulkheads in the field only if you observe and can verify an optical output problem.
Connectors and Bulkheads
Most fiber optic connectors are of the physical contact (PC) type. PC type connectors are designed to touch their mating connector to prevent air gaps, which cause reflections. For optimum performance, all dirt must be removed.
Bulkheads can also become dirty enough to affect performance, either from airborne dust or from contamination introduced by connectors.
WARNING:
Avoid damage to your eyes! Do not look into any optical connector while the system is active. Even if the unit is off, there may still be hazardous optical
levels present.
Note: Read the above warning before performing cleaning procedures.
135
Chapter 5 Maintenance
136
Cleaning Connectors
It is important that all external jumper connectors be cleaned before inserting them into the optical module. Follow these steps to clean fiber optic connectors that will be connected to the optical module:
Important: Before you begin, remove optical power from the module or ensure that optical power has been removed.
1 Inspect the connector through an optical connector scope. If the connector is damaged, e.g., scratched, burned, etc., replace the jumper.
2 If the connector is dirty but otherwise undamaged, clean the connector as follows:
a Make several swipes across the face of the connector with the appropriate ferrule cleaner. This will remove dust and some films.
b Listen for a slight "squeak" typically generated during this process, indicating a clean connector.
c Inspect the connector again through the scope to confirm that it is clean.
3 If a second inspection indicates that further cleaning is needed:
a Use 99% isopropyl alcohol and a lint-free wipe to clean the connector.
b Use the appropriate ferrule cleaner again to remove any film left over from the alcohol.
c Inspect the connector again through the scope and confirm that it is clean.
4 If necessary, repeat steps 3a-3c until the connector is clean.
Cleaning Bulkheads
Note: It is generally more difficult to clean bulkhead connectors and verify their condition due to limited accessibility of the fiber end face. For this reason, even on products with accessible bulkhead connectors, you should only attempt to clean a bulkhead connector when a dirty connector is indicated.
Follow these steps to clean the bulkhead:
WARNING:
Avoid personal injury! Use of controls, adjustments, or performance of procedures other than those specified herein may result in hazardous
radiation exposure.
Avoid personal injury! The laser light source on this equipment emits
invisible laser radiation. Avoid direct exposure to the laser light source.
Avoid personal injury! Viewing the laser output with optical instruments
(such as eye loupes, magnifiers, or microscopes) may pose an eye hazard.
Care and Cleaning of Optical Connectors
1 Insert a dry bulkhead swab into the bulkhead and rotate the swab several times.
2 Remove the swab and discard. Swabs may be used only once.
3 Check the bulkhead optical surface with a fiber connector scope to confirm that it is clean. If further cleaning is needed:
a Moisten a new bulkhead swab using a lint-free wipe moistened with optical-grade (99%) isopropyl alcohol.
b With the connector removed, fully insert the bulkhead swab into the bulkhead and rotate the swab several times.
c Remove the swab and discard. Swabs may be used only once.
d Check with a fiber connector scope again to confirm that there is no dirt or alcohol residue on the optical surface.
e If any alcohol residue remains, clean it off with a new dry bulkhead swab.
4 Mate all connectors to bulkheads and proceed to Verifying Equipment
Operation below.
5 It is also recommended that all connectors be visually inspected after cleaning to verify the connector is clean and undamaged.
Verifying Equipment Operation
Perform circuit turn-up. If the equipment does not come up, i.e., fails verification or indicates a reflection problem, clean the connectors and bulkheads again.
For Further Assistance
If you have any questions or concerns about cleaning fiber optic connectors, contact
Customer Service using the contact information provided in the Customer Support
Information chapter.
137
6
Chapter 6
Troubleshooting
Introduction
This troubleshooting section lists common problems and their solutions.
Replacing Modules
If a troubleshooting procedure directs you to replace a module of the
1.2 GHz GS7000 Node, see Removing and Replacing Modules (on page
In This Chapter
No RF Output: Fiber Optic Light Level is Good, Receiver
Optical Power LED is on .................................................................... 142
Poor C/N Performance ...................................................................... 144
Poor Distortion Performance ............................................................ 146
Poor Frequency Response .................................................................. 148
No RF Output from Reverse Receiver ............................................. 150
139
Chapter 6 Troubleshooting
No RF Output at Receiver RF Test Point: Optical
Power LED on Receiver Module is off
Troubleshooting Flowchart
Follow this troubleshooting flowchart. Also see the notes following the chart.
140
No RF Output at Receiver RF Test Point: Optical Power LED on Receiver Module is off
Notes
These notes apply to the previous troubleshooting flowchart.
Note
1
2
Description
For standard receiver
This unit will have no RF output.
The receiver will not function below this DC level which is equal to
10 dBm.
The optimum light level input is -6 to 2 dBm.
For every 1 dBm change in optical input power, the RF output will change by 2 dB.
Excessively high light input levels
(> +2 dBm) will cause distortions and/or damage the photo diode.
For low input receiver
This unit will have no RF output.
The receiver will not function below this DC level which is equal to
10 dBm.
The optimum light level input is
-10 to -2 dBm.
For every 1 dBm change in optical input power, the RF output will change by 2 dB.
Excessively high light input levels
(> -2 dBm) will cause distortions and/or damage the photo diode.
141
Chapter 6 Troubleshooting
No RF Output: Fiber Optic Light Level is Good,
Receiver Optical Power LED is on
Troubleshooting Flowchart
Follow this troubleshooting flowchart. Also see the notes following the chart.
142
No RF Output: Fiber Optic Light Level is Good, Receiver Optical Power LED is on
Notes
These notes apply to the previous troubleshooting flowchart.
Note Description
1
2
For standard receiver
If the green LED is Off, it is outside optical input range. Green (On) indicates that light is present and the optical input value is higher than -10 dBm.
The recommended RF output level at the output of the receiver module is 27 dBmV (+7.0 dBmV as measured at the
-20 dB RF test point). This setup is recommended to achieve the best possible performance.
For low input receiver
If the green LED is Off, it is outside optical input range. Green (On) indicates that light is present and the optical input value is higher than -14 dBm.
The recommended RF output level at the output of the receiver module is 27 dBmV (+7.0 dBmV as measured at the
-20 dB RF test point). This setup is recommended to achieve the best possible performance with 8 dB setting.
Note:
- Assumes 2.5% OMI/CH or 20% composite.
- Assumes 1310 nm wavelength / Add one dB for 1550
- Assumes 0dB attenuator switch setting unless noted, if otherwise subtract attenuator value from reading
- Assumes -4dB optical input, if otherwise add or subtract 2dB RF for each 1dB optical input
143
Chapter 6 Troubleshooting
Poor C/N Performance
Troubleshooting Flowchart
Follow this troubleshooting flowchart. Also see the notes following the chart.
144
Poor C/N Performance
Notes
These notes apply to the previous troubleshooting flowchart.
Note
1
2
3
Description
RF drive level to the laser must be set to the laser manufacturer’s specification.
It is possible that the distribution module is set up incorrectly. See the pad and equalizer selection charts in Appendix A for correct pad and equalization. The
C/N performance will suffer if the RF levels are too low into the first gain stage or the interstage.
It is important to monitor the DC level at the receiver module because in the process of cleaning the connectors, the transfer of light through each connector may improve or degrade. The DC reading should degrade if there is a reflection in the path depending on the severity of the core mismatch. Scratches on the surface of the fiber of the connector can cause reflections. Scratched connectors must be replaced.
4
For standard receiver
Attenuate the light to simulate the amount of light that should be at the
1.2 GHz GS7000 Node and rerun the
C/N performance. Add components into the path one at a time until the problem is found. Change jumpers, couplers, fibers and connectors one at a time, taking C/N measurements after each change.
A phenomenon called “shot noise” will occur if the light level is too high into the receiver. This is noise generated by the photo diode when the light is converted back to RF. An optical input level exceeding +2 dBm at the detector will also generate distortions.
For low input receiver
Attenuate the light to simulate the amount of light that should be at the
1.2 GHz GS7000 Node and rerun the
C/N performance. Add components into the path one at a time until the problem is found. Change jumpers, couplers, fibers and connectors one at a time, taking C/N measurements after each change.
A phenomenon called “shot noise” will occur if the light level is too high into the receiver. This is noise generated by the photo diode when the light is converted back to RF. An optical input level exceeding -2 dBm at the detector will also generate distortions.
145
Chapter 6 Troubleshooting
Poor Distortion Performance
Troubleshooting Flowchart
Follow this troubleshooting flowchart. Also see the notes following the chart.
146
Poor Distortion Performance
Notes
These notes apply to the previous troubleshooting flowchart.
Note
1
Description
Recommended RF input levels are:
Headend transmitter module: 14 dBmV
Note: Based on 79-channel loading. The input will increase as the channel loading decreases.
2
3
4
For standard receiver
The range for optical light input level is -6 to +2 dBm which converts to 0.25 to 1.6 V DC. The optimum operating range is -3 dBm to +2 dBm which converts to 0.5 to 1.6 V DC. Levels higher than +2 dBm can cause the photo diode to generate distortions, which add to the distortion performance of the link, effectively degrading the distortion performance.
For low input receiver
The range for optical light input level is -10 to -2 dBm which converts to 0.1 to 0.6 V DC. The optimum operating range is -6 dBm to -2 dBm which converts to 0.25 to 0.6 V DC. Levels higher than -2 dBm can cause the photo diode to generate distortions, which add to the distortion performance of the link, effectively degrading the distortion performance.
Attenuate the light to simulate the amount of light that should be at the 1.2 GHz
GS7000 Node and rerun the distortion performance. If the distortion performance improves, there is too much light. An inline optical attenuator or a coupler with a higher loss can reduce the light, or the laser may have to be replaced with a lower launch power.
Attenuate the RF input level into the amplifier by increasing the pad value at the OIB. If the distortion perform improves, there is too much RF.
147
Chapter 6 Troubleshooting
Poor Frequency Response
Troubleshooting Flowchart
Follow this troubleshooting flowchart. Also see the notes following the chart.
148
Poor Frequency Response
Notes
These notes apply to the previous troubleshooting flowchart.
Note
1
2
Description
Be sure all unused ports are properly terminated into 75 ohms to prevent mismatches. The frequency response is cumulative and reflects the response of each active device in the link:
The frequency response for the transmitter is dependent on the transmitter manufacturer's specification.
The frequency response of the 1.2 GHz GS7000 Node is ±1.0 dB from 52
MHz to 1218 MHz (for optical receiver and amplifier combined).
It is possible that the RF amplifier is set up incorrectly. Always check to see that padding and equalization is correct to ensure proper levels at the inputs to each gain stage. See the pad and equalizer selection charts in Appendix A for correct pad and equalization.
149
Chapter 6 Troubleshooting
No RF Output from Reverse Receiver
Troubleshooting Flowchart
Follow this troubleshooting flowchart.
150
7
Chapter 7
Customer Support Information
If You Have Questions
If you have technical questions, call Cisco Services for assistance.
Follow the menu options to speak with a service engineer.
Access your company's extranet site to view or order additional technical publications. For accessing instructions, contact the representative who handles your account. Check your extranet site often as the information is updated frequently.
151
A
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Appendix A
Technical Information
In This Appendix
Forward Equalizer Chart ................................................................... 156
Introduction
This appendix contains tilt, forward and reverse equalizer charts and pad values and part numbers.
153
Appendix A
Technical Information
Linear Tilt Chart
Amplifier Output Linear Tilt Chart for 1.2 GHz
The following chart can be used to determine the operating level at a particular frequency considering the operating linear tilt.
154
Linear Tilt Chart
Amplifier Output Linear Tilt Chart for 1 GHz
The following chart can be used to determine the operating level at a particular frequency considering the operating linear tilt.
Example: If the amplifier’s 1 GHz output level is 49.0 dBmV with a linear operating tilt of 14.5 dB (from 50 to 1 GHz), the corresponding output level at 750 MHz would be 45.1 dBmV. This was found by taking the difference in tilt between 1 GHz and 750
MHz (14.5 – 10.6 = 3.9 dB). Then subtract the difference in tilt from the operating level (49.0 - 3.9 = 45.1 dBmV).
155
Appendix A
Technical Information
Forward Equalizer Chart
1.2 GHz Forward Linear Equalizers
The following table shows the 1.2 GHz forward linear equalizer loss.
EQ Value Insertion Loss at (MHz) Total Tilt
1.2
1.2
1.2
1.0
1.0
1.0
1.0
1.2
1.0
1.0
1.0
1.0
1218
1.0
1.0
1.0
1.0
16.5
18.0
19.5
21.0
10.5
12.0
13.5
15.0
22.5
24.0
4.5
6.0
7.5
9.0
(dB)
1.5
3.0
1000
1.3
1.6
1.8
2.1
2.4
2.6
2.9
3.2
3.5
3.7
4.0
4.3
4.8
5.0
5.3
5.6
16.5
18.0
19.5
21.0
10.5
12.0
13.5
15.0
22.5
24.0
4.5
6.0
7.5
9.0
(52-1218 MHz)
1.5
3.0
156
Forward Equalizer Chart
1 GHz Forward Linear Equalizers
The following table shows the 1 GHz forward linear equalizer loss.
1.0
1.0
1.0
1.0
1.5
1.5
1.5
1.0
1.0
1.0
1.0
1.0
1.0
1.0
EQ Value Insertion Loss at (MHz)
(dB) 1000 870 750 650
15.0
16.5
18.0
19.5
21.0
7.5
9.0
10.5
12.0
13.5
1.5
3.0
4.5
6.0
4.0
4.2
4.4
2.6
2.9
3.1
3.3
1.8
2.0
2.2
2.4
1.2
1.4
1.6
6.3
6.7
7.1
4.2
4.6
5.0
5.4
2.6
3.0
3.4
3.8
1.4
1.8
2.2
8.2
8.7
9.2
5.4
6.0
6.5
7.1
3.2
3.8
4.3
4.9
1.6
2.1
2.7
600
6.1
6.7
7.3
8.0
9.1
9.7
10.2
3.5
4.2
4.8
5.4
1.6
2.3
2.9
550 86 70 52
3.8
4.6
5.3
6.0
1.7
2.4
3.1
2.4
3.9
5.3
2.5
3.9
5.4
2.5
4.0
5.5
6.8
8.2
6.9
8.4
7.0
8.5
9.7 9.8 10.0
11.1 11.3 11.5
6.7
7.4
8.1
8.9
12.6 12.8 13.0
14.0 14.2 14.5
15.5 15.7 16.0
16.9 17.2 17.5
10.1 18.9 19.2 19.5
10.8 20.3 20.6 21.0
11.5 21.8 22.1 22.5
Total Tilt
15.0
16.5
18.0
19.5
21.0
7.5
9.0
10.5
12.0
13.5
(52-1000
MHz)
1.5
3.0
4.5
6.0
157
158
Appendix B
Enhanced Digital Return Multiplexing Applications
B
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Appendix B
Enhanced Digital Return
Multiplexing Applications
This appendix explains the installation and application of the Cisco
Enhanced Digital Return (EDR) 85 Multiplexing System in the GS7000
Node.
The products are intended for digital transmission of reverse path signals over a fiber optic link from the node to the headend.
The Cisco Enhanced Digital Return (EDR) 85 System expands the functionality of GS7000 and GainMaker 4-Port and Reverse
Segmentable Nodes by increasing the performance, reach, and efficiency of the reverse path transmissions.
The Cisco EDR 85 System includes EDR Transmitter modules that install in GainMaker and GS7000 Nodes, and companion Cisco
Prisma® high-density (HD) EDR PRX85 Receiver modules that install in a Prisma II or Prisma II XD chassis at the headend or hub. The transmitter and receiver use Small Form Factor Pluggable (SFP) optical pluggable modules (OPMs) for enhanced flexibility. The Cisco EDR 85
System operates over the 5-85 MHz range and supports all standard reverse frequency bandwidths at 40, 42, 55, 65, and 85 MHz.
The Cisco Enhanced Digital Return (EDR) 85 Systems includes the
EDR 1:1 multiplexing system and the 2:1 multiplexing system.
In This Appendix
Enhanced Digital Return System Overview ................................... 159
Enhanced Digital Return (EDR) System Installation ..................... 177
Transmitter Module Setup Procedure ............................................. 186
Reverse Balancing the Node with EDR ........................................... 189
Enhanced Digital Return System Overview
Enhanced Digital Return System Overview
Features
The EDR Enhanced Digital Return 1:1 and 2:1 Multiplexing Systems have the following features.
High-performance Digital Return technology
12 bit encoding enables transmission of analog video in the reverse band
High-order digital modulation signals (e.g.,16 QAM, 64 QAM, and 256
QAM)
Multiple operating modes in the EDR receiver support EDR transmitter
Optical Pluggable Modules (OPM) enable flexible inventory management
Long reach transmission capabilities eliminate the need for optical amplifiers, reducing cost and space requirements
Capable of sending 80 individual 5 – 85 MHz reverse signals over a single fiber
Compatible with Cisco’s 40 wavelength DWDM system
Enables independent balancing of reverse traffic at EDR receiver RF ports
Simplified setup reduces installation time and expertise requirements
Distance- and temperature-independent link performance simplifies engineering and maintenance requirements
Space-saving, high-density deployment in Prisma II or Prisma II XD chassis increases deployment cost-efficiency
Optional monitoring of node (GS7000) and Tx (GS7000 and GainMaker) parameters available at the receiver
The EDR 2:1 Enhanced Digital Return Multiplexing System leverages 2:1 multiplexing to reduce fiber usage.
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Appendix B
Enhanced Digital Return Multiplexing Applications
System Functional Diagrams
Single Transmitter Configuration
Single Transmitter Configuration for EDR 1:1 Transmitter Module
The following illustration shows how the GS7000 Node functions in Enhanced
Digital Return configuration with one 1:1 EDR transmitter module installed as the single transmitter.
160
Important: This configuration requires a 4x1 Reverse Configuration Module (for
6-port OIB), as shown.
Enhanced Digital Return System Overview
Single Transmitter Configuration for EDR 2:1 Transmitter Module
The following illustration shows how the GS7000 Node functions in Enhanced
Digital Return configuration with one 2:1 EDR transmitter module installed as the single transmitter.
Note: When the node is configured in either segmented or EDR mode, a 75 dB pad must be placed in the Tx2 SM Term.
Important: This configuration requires a 4x2 Reverse Configuration Module (for
6-port OIB), as shown.
161
Appendix B
Enhanced Digital Return Multiplexing Applications
Full Configuration
Full Configuration for EDR 1:1 Transmitter Module
The following illustration shows how the GS7000 Node functions in Enhanced
Digital Return configuration with four 1:1 EDR transmitter modules installed as the maximum configuration.
Note: When the node is configured in either segmented or EDR mode, a 75 dB pad must be placed in the Tx2 SM Term.
162
Important: This configuration requires a 4x4 Reverse Configuration Module as
Enhanced Digital Return System Overview
shown.
Full Configuration for EDR 2:1 Transmitter Module
The following illustration shows how the GS7000 Node functions in Enhanced
Digital Return configuration with two 2:1 EDR transmitter modules installed as the maximum configuration.
Note: When the node is configured in either segmented or EDR mode, a 75 dB pad must be placed in the Tx2 SM Term.
Important: This configuration requires a 4x4 Reverse Configuration Module as shown.
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Appendix B
Enhanced Digital Return Multiplexing Applications
System Block Diagram
System Block Diagram for EDR 1:1 Transmitter Module
The following is a block diagram of the EDR Enhanced Digital Return 1:1
Multiplexing System.
164
System Block Diagram for EDR 2:1 Transmitter Module
Enhanced Digital Return System Overview
The following is a block diagram of the EDR Enhanced Digital Return 2:1
Multiplexing System.
165
Appendix B
Enhanced Digital Return Multiplexing Applications
EDR Transmitter Module
At the transmit (node) end of the system, reverse-path RF input signals from each node port are routed to an EDR 2:1 or EDR 1:1 Transmitter module in the housing lid.
The transmitter module converts each signal to a baseband digital data stream and combines the signals into a serial data stream using time-division multiplexing
(TDM). The baseband data stream is then converted to an optical signal for transmission to the headend or hub. The double-wide (2:1) transmitter modules occupy two transmitter slots and the 1:1 modules occupy one slot.
The EDR 1:1 transmitter introduces one single RF inputs to produce the discrete 5 to
85 MHz RF signal, while the EDR 2:1 transmitter introduces two RF inputs to produce two discrete 5 to 85 MHz RF signals. The transmitter module also converts each signal to a baseband digital data stream and time division multiplexes the two streams into a single data stream.
The data stream is carried optically over fiber, via an SFP type OPM module, to a remote hub or headend location where the optical signal is detected and converted back to a serial electrical signal. The data is then de-scrambled and de-framed and switched to a Digital-to-Analog Converter (DAC), where the analog spectrum that was sampled at the transmit side is reconstructed. The baseband data stream is converted to an optical signal for transmission back to the headend or hub.
The following block diagrams show the transmitter module's internal components.
For EDR 1:1 Transmitter Module
166
For EDR 2:1 Transmitter Module
Enhanced Digital Return System Overview
The following illustrations show the transmitter module components.
For EDR 1:1 Transmitter Module
Note:
1. The EDR transmitter cannot monitor the GainMaker Node parameters.
2. The EDR LCM module needs to be installed for EDR transmitter status monitoring.
3. The status monitor interface is not used for data transmission. The Cisco DOCSIS transponder is needed when data transmission is required.
The transmitter module uses the same style housing as the optical receivers and transmitters, and it uses the single-wide module housing. As such, it occupies one
167
Appendix B
Enhanced Digital Return Multiplexing Applications
standard transmitter positions in the node lid.
For EDR 2:1 Transmitter Module
168
Note:
1. The EDR transmitter cannot monitor the node parameters.
2. The EDR LCM module needs to be installed for EDR transmitter status monitoring.
3. The status monitor interface is not used for data transmission. The Cisco DOCSIS transponder is needed when data transmission is required.
The transmitter module uses the same style housing as the optical receivers and transmitters, except that it uses double-wide module housing. As such, it occupies two standard transmitter positions in the node lid.
The following illustrations show the location of the modules in the node.
For EDR 1:1 Transmitter Module
Enhanced Digital Return System Overview
Note: This example shows four transmitter modules installed in the node, which requires a 4x4 Reverse Configuration Module.
169
Appendix B
Enhanced Digital Return Multiplexing Applications
For EDR 2:1 Transmitter Module
170
Note: This example shows two transmitter modules installed in the node, which requires a 4x4 Reverse Configuration Module.
Enhanced Digital Return System Overview
EDR Receiver Module
At the receive end, typically in a large hub or headend, the EDR Receiver module receives the optical signal and performs the conversion back to the baseband data stream. The resulting data streams are converted back to analog reverse path signals for routing to termination equipment. The EDR Receiver module is available in the
High Density form factor. The receiver OPMs are available in Standard Range (SR) and Extended Range (XR) configurations. Both configurations feature a dual LC/PC optical input connector that feeds two independent reverse optical receivers, each with its own RF output port.
A single EDR Receiver module occupies one slot in a Cisco Prisma II XD chassis.
Two EDR HD receiver modules can be vertically stacked in an associated Prisma II
Host Module that occupies a single-wide slot in the Prisma II standard chassis. Up to
26 HD modules can operate in a standard 6 rack unit (6RU) chassis (the 56-connector version of the chassis is required to make use of both receivers in one chassis slot).
Up to 16 HD modules can operate in the Prisma II XD chassis. The ability to mix
EDR Receiver modules with other Prisma II HD modules in the same chassis greatly enhances the flexibility of the platform.
For instructions on installing the receiver refer to the Prisma II Chassis Installation
and Operation Guide, part number 713375.
The following block diagram shows the receiver module's internal components.
At the headend, the reverse optical receiver converts the optical signal back to an RF signal that is then routed out through the receiver's RF output.
Refer to the Cisco Prisma II EDR Receiver Installation Guide, part number
OL-29646, for detailed information on the EDR receiver module.
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Appendix B
Enhanced Digital Return Multiplexing Applications
Receiver Module Diagram
The following illustration shows the receiver module.
172
Enhanced Digital Return System Overview
Receiver Operating Modes
The receiver module supports receiver mode configuration performed by setting the proper mode ID numbers in the Prisma II Web UI system.
The following diagrams provide a basic walk-through of all the supported modes for the EDR receiver module.
The receiver can be configured for any of the following modes of operation:
Single 2:1
Dual 1:1
Dual 2:1
Single 2:1 on Primary + Single 1:1 on Secondary
Single 1:1 on Primary + Single 2:1 on Secondary
Legacy Single 2:1
Legacy Dual 2:1
Each of these operating modes is described below.
Single 2:1 Mode
Referring to the diagram below, the EDR transmitter digitizes and combines two RF signals (RF 1 + RF 2) into one serial stream and transmits is over optical fiber to the receiver. At the receiver, the serial stream is de-serialized, converted back to its two analog RF components, and then sent to the two RF connectors on the back of the module. RF 1 appears on RF port A, and RF 2 appears on RF port B.
Note: The optical fiber must be plugged into the top receiver on the OPM.
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Dual 1:1 Mode
Referring to the diagram below, the EDR transmitter digitizes a single RF signal (RF
1) into a serial stream and transmits it over optical fiber to the receiver. At the receiver, the serial streams from two separate transmitters are deserialized and converted back to an analog RF signal. The RF signal (RF 1) for each transmitter is sent separately to the two RF connectors on the back of the module.
Dual 2:1 Mode
Referring to the diagram below, two EDR transmitters are connected to one receiver.
Each EDR transmitter digitizes and combines two RF signals (RF 1 + RF 2) into one serial stream and transmits it over optical fiber to the receiver. At the receiver, the serial streams from the two separate transmitters are deserialized and converted back to their two analog RF components. Since the receiver only has two RF ports, the combined signals (RF 1 + RF 2) for each transmitter are sent to the two RF connectors on the back of the module.
174
Enhanced Digital Return System Overview
Single 2:1 on Primary + Single 1:1 on Secondary
This mode is a combination of the 2:1 and 1:1 modes described above. Referring to the diagram below, one EDR transmitter digitizes and combines two RF signals (RF
1 + RF 2) into one serial stream and transmits it over optical fiber to the receiver. The other EDR transmitter digitizes a single RF signal (RF 1). At the receiver, the serial streams from two separate transmitters are deserialized and converted back to their two analog RF components. The combined Transmitter 1 signal (RF 1 + RF 2) is sent to RF port A, and the Transmitter 2 signal (RF 1) is sent to RF port B on the back of the module.
Single 1:1 on Primary + Single 2:1 on Secondary
This mode is identical to the mode just described, except that the 2:1 transmitter is connected to the second receiver and the 1:1 transmitter is connected to the primary receiver.
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Appendix B
Enhanced Digital Return Multiplexing Applications
EDR OPM and LCM
About the OPM Module
The reverse transmitter converts the RF test signal(s) to an optical signal using the installed Optical Module (OPM) and transmits it to the headend (or hub site) via fiber optic cable. At the headend, the reverse optical receiver also converts the optical signal back to an RF signal that is then routed out through the receiver's RF output using its installed OPM module.
Item
1
Description
Dust Plug
2
3
Bale Clasp (Open, Push upward to close)
Transmit Bore (Not In Use for the Receiver)
4 Receive Bore (Not In Use for the Transmitter)
176
About the EDR LCM
The EDR Local Control Module is required for in-band status monitoring the node signaling and data transmission.
The packet cable is delivered with the EDR LCM module. Refer to the installation section in the following content for instructions on local status monitoring connection.
Refer to the following sections for EDR OPM and LCM installation.
Enhanced Digital Return (EDR) System Installation
Enhanced Digital Return (EDR) System Installation
Before You Begin
Overview
Perform these installation instructions only if you are upgrading the GS7000 Node with the EDR. If your node came with the EDR installed, go to Reverse Balancing the
Node with Digital Return Modules (on page 234).
Required Tools
The following tools and equipment are needed to configure and install the EDR.
½-inch hex driver or ratchet
Two adjustable wrenches for coaxial connectors
Standard flat-head or phillips-head screwdriver
Torque wrench, capable of settings up to 100 in-lb (11.3 Nm)
Operating Environment
Before operating the node with the EDR installed, ensure that the operating environment meets the following standards.
Ambient temperature range outside the node must be maintained between -40°C and +60°C (-40°F to 140°F).
Storage temperature range of the EDR must be maintained between -40°C to
+85°C (-40°F to 185°F).
Humidity range must be maintained between 5% to 95% non-condensing before installation of the EDR Digital Return module(s).
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Installing the EDR Transmitter
The transmitter module uses the same style housing as the optical receivers and transmitters, except that it uses double-wide module housing. As such, it occupies two standard transmitter positions in the node lid.
If your EDR transmitter comes without OPM module installed, you need to order the fiber jumper and the OPM module from our sales representatives, and perform the following steps to install the OPM module and connect the fiber jumper to the installed OPM module before installing the EDR transmitter.
To Install the OPM Module in the EDR Transmitter
CAUTION:
The OPM modules are electro-static sensitive devices. Always use an ESD wrist strap or similar individual grounding device when handling OPM modules or coming in contact with modules.
1. Connect the blue LC connector to the transmit bore of the OPM module before installing the module. Refer to the EDR OPM and LCM section on page 238 for details for the OPM module.
2. Close the bale-clasp before inserting the OPM module.
178
3. Connect the blue LC connector to the transmit bore of the OPM module.
4. Line up the OPM module with the port, and slide it into the port.
Enhanced Digital Return (EDR) System Installation
5. Proceed to next section for installation.
The following diagram shows the OPM module installed on the 1:1 transmitter module.
The following diagram shows the OPM module installed on the 2:1 transmitter module.
CAUTION:
Removing and installing an OPM module can shorten its useful life. Do not remove and insert OPM modules more often than is absolutely necessary.
179
Appendix B
Enhanced Digital Return Multiplexing Applications
To Route the Fiber Jumper
Make sure the transmitter module is installed with the OPM module before routing the fiber jumper. The fiber jumper must be routed carefully in the fiber tray and aligned under the fiber jumper clip one by one.
The following diagram shows the fiber jumper connection for 1:1 transmitter.
The following diagram shows the fiber jumper connection for 2:1 transmitter.
180
Note:
1. When removing faulty OPM module, press and remove the blue LC connecter before you can open the bale clasp.
2. OPM modules should be installed before installing the fiber jumper.
Enhanced Digital Return (EDR) System Installation
To Install the EDR Transmitter
Follow these steps to install the transmitter module(s).
1 See Module Replacement Procedure (on page 127) for instructions on installing
these modules in the housing.
2 Remove any existing transmitter modules from the positions in which you want to install the EDR transmitter module(s).
3 Install one to four 1:1 transmitter modules in the housing lid as required for your application.
IF you are installing...
only one transmitter module
Two or three transmitter modules
THEN...
install the module in transmitter positions XMTR 1
AND install an appropriate Reverse Configuration Module in the RF amplifier assembly.
Refer to the RCM Section on page 40 for details. install the modules in transmitter positions XMTR 1/XMTR 2, or XMTR 1/XMTR 2/XMTR 3
AND install an appropriate Reverse Configuration Module in the RF amplifier assembly.
Refer to the RCM Section on page 40 for details. four transmitter modules install the modules in transmitter positions XMTR 1/XMTR 2/
XMTR 3/XMTR 4
AND install an appropriate Reverse Configuration Module in the RF amplifier assembly.
Refer to the RCM Section on page 40 for details.
4 Install one or two 2:1 transmitter modules in the housing lid as required for your application.
IF you are installing...
only one transmitter module
THEN...
install the module in transmitter positions XMTR 1/XMTR 2
AND install an appropriate Reverse Configuration Module in the RF amplifier assembly.
Refer to the RCM Section on page 40 for details.
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Appendix B
Enhanced Digital Return Multiplexing Applications
two transmitter modules install the modules in transmitter positions XMTR 1/XMTR 2 and XMTR 3/XMTR 4
AND install an appropriate Reverse Configuration Module in the RF amplifier assembly.
Refer to the RCM Section on page 40 for details.
The following illustrations show the location of the installed modules in the node.
For EDR 1:1 Transmitter Module:
182
For EDR 2:1 Transmitter Module:
Enhanced Digital Return (EDR) System Installation
WARNING:
Laser transmitters when disconnected from their optical fiber path emit invisible laser radiation, which is harmful to the human eye. If viewed at close range, the radiation may be of sufficient power to cause instantaneous damage to the retina of the eye. Only trained service personnel using proper safety precautions and equipment such as protective eyewear should disconnect and service the laser transmitter equipment.
To Connect the Long-haul Fiber
1. Insert the fiber-optic start-head to the optical adapter.
2. Route fiber on the fiber tray of GS7000 GainMaker Node.
3. Connect the fiber-optic end-head to the receive bore of the OPM module installed on the Receiver of the Prisma II platform.
4. The receiver OPM module requires LC connector, conversion maybe needed.
5. Clean the LC connector's fiber-optic end-faces.
See the following Tip for a pointer to a fiber-optic inspection and cleaning white paper. http://www.cisco.com/en/US/tech/tk482/tk876/technologies_white_paper09186a
0080254eba.shtml
To Connect the EDR LCM for Status Monitoring
The LCM module is equipped with the interface ribbon cable. The cable can be used to connect the LCM module and the Status Monitor point of the desired EDR transmitter module for local status monitoring.
Note: Local Status monitoring supports one EDR transmitter module at a time.
The following diagrams show how to connect the interface ribbon cable.
Note: Insert the cable head-end with the red marker on back.
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When EDR 1:1 transmitter module is installed:
When EDR 2:1 transmitter module is installed:
184
Press the Auto Set-Up button on the LCM to initiate module discovery.
The Auto-Setup process typically takes up to 30 seconds.
Note: Node data monitoring is only available for GS7000 Nodes with a transponder-less EDR LCM installed. The PC-based GS7000 ViewPort software is not available for GS7000 Node.
Enhanced Digital Return (EDR) System Installation
Installing the EDR Receiver
Refer to the Cisco Prisma II EDR Receiver Installation Guide, part number 4044294, for detailed information on installing the EDR receiver module on the Prisma II.
To Install the OPM Module on the Receiver Module
The following diagram shows the OPM module installed on the receiver module of the Prisma II.
To Configure the Receiver Mode
The receiver mode can be configured in the Web UI interface though connection with the Prisma II platform.
For complete configuration steps and setup precautions, refer to the Cisco Prisma II
EDR Receiver Installation Guide, part number OL-29646, and the Cisco Prisma II
Platform Configuration Guide, after system release 2.05.30, part number OL-27998.
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Transmitter Module Setup Procedure
Perform the following steps to set up the reverse transmitter module(s).
1 Open the housing according to Opening and Closing the Housing (on page 122).
2 In the base of the housing verify that the Reverse Configuration Module installed in the RF amplifier is correct for your application.
IF you have installed...
The minimum configuration of one
1:1 transmitter module in transmitter positions XMTR 1
THEN the installed Reverse Configuration
Module must be...
an appropriate Reverse Configuration Module
Refer to the RCM Section on page 40 for details.
The minimum configuration of one
2:1 transmitter module in transmitter positions XMTR 1/XMTR 2 an appropriate Reverse Configuration Module
Refer to the RCM Section on page 40 for details.
The maximum configuration of two
2:1 transmitter modules in transmitter positions XMTR 1/XMTR
2 and XMTR 3/XMTR 4 an appropriate Reverse Configuration Module
Refer to the RCM Section on page 40 for details.
The maximum configuration of four
1:1 transmitter modules in transmitter positions XMTR 1/XMTR
2 and XMTR 3/XMTR 4 an appropriate Reverse Configuration Module
Refer to the RCM Section on page 40 for details.
3 Verify the level of the reverse path RF signal at the RF test points on the RF module. Nominal level is +15 dBmV per channel. Install the appropriate value input pad at the REV PORT IN PAD location to give the desired signal level into the node.
4 Repeat step 3 for each RF cable carrying a reverse path signal.
5 Measure the transmitter module(s) optical output power.
6 Check the connection of the optical connector. Make sure the optical connector is seated and verify fiber bend radius is greater than 1 inch.
WARNING:
When handling optical fibers always follow laser safety precautions.
186
Transmitter Module Setup Procedure
EDR Transmitter Status Indicators
The transmitter module has two status indicator LEDs.
The following section describes the LED status and the correspondent indications.
The input level overdrive indicates the input signal level exceeds the limit of 35 dBmV.
For EDR 1:1 transmitter module
The following table lists the LED status and the indicated OPM, and the overdrive status of the RF port.
LED
Power (PWR) Laser (LSR) OPM Module
Indication
Port Input Overdrive
OFF
Green
Green
OFF
Green
Orange
(Solid)
Green
-
Cisco Standard OPM Module
Non-Cisco Standard OPM
Module
Cisco Standard OPM Module
-
No
No
Green
Orange
(Blink)
Yes
For EDR 2:1 transmitter module
The following table lists the LED status and the indicated OPM, and the overdrive status of both RF port 1 and RF port 2.
LED
Cisco Standard OPM Module/
Non-Cisco Standard OPM
Module
Power (PWR) Laser (LSR)
OFF OFF
OPM Module
-
Indication
Port 1 Input
Overdrive
-
Port 2 Input
Overdrive
-
Green
Green
Green
Green
Orange
(Solid)
Orange
(Blink)
Cisco Standard OPM Module
Non-Cisco Standard OPM
Module
Cisco Standard OPM Module
No
No
No
No
No
Yes
Orange
(Blink)
Yes No
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Orange
(Blink)
Orange
(Blink)
Orange
(Solid)
Orange
(Blink)
Non-Cisco Standard OPM
Module
Cisco Standard OPM Module
Yes
Yes
No
Yes
188
Reverse Balancing the Node with EDR
Reverse Balancing the Node with EDR
Introduction
This section explains the reverse balancing procedures for the GS7000 Node using
EDR.
When balancing the reverse path, reference your system design print for the required reverse signal level. Use appropriate padding and equalization to provide proper signal level to the reverse transmitter.
CAUTION:
Never attempt to reconfigure the unit beyond its normal setup. Changes to the node’s configuration may cause degradations that affect its performance. Do not use digital carrier measurement to set up the forward or reverse paths.
Familiarize yourself with your cable system’s specifications before
performing the setup.
There are a variety of test equipment combinations that enable proper balancing of the reverse path. Regardless of the type of equipment used, the balancing process is fundamentally the same. A reverse RF test signal (or signals) of known amplitude is injected into the RF path at the RF input of the node. The reverse transmitter converts the RF test signal(s) to an optical signal and transmits it to the headend (or hub site) via fiber optic cable. At the headend, the reverse optical receiver converts the optical signal back to an RF signal that is then routed out through the receiver's
RF output. The amplitude of the injected test signal must be monitored at the receiver's output, and compared to the expected (design value) amplitude.
Method of Generating and Monitoring Test Signals
The reverse RF test signals that are injected into the reverse path of the RF launch amplifier being balanced may be generated by the following method.
Multiple CW signal (tone) generator
Reverse sweep transmitter
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The amplitude of the received test signals at the output of the reverse optical receiver in the headend or hub may be measured and monitored using the following:
Spectrum analyzer (when using a CW generator for test signals)
Signal level meter (when using a CW generator for test signals)
Reverse sweep receiver (when using a reverse sweep transmitter for test signal)
The variance in relative amplitude of the received signal from desired (reference) may be relayed to the field technician via the following:
Radio (by a second technician in the headend/hub who is monitoring a spectrum analyzer or signal level meter)
A dedicated forward TV channel, whose associated modulator has its video input being generated by a video camera focused on the spectrum analyzer display
An associated forward data carrier (if using a particular type of reverse sweep system)
If a portable reverse sweep generator with built-in forward data receiver is used to generate the reverse test signals, only one technician is required to perform the balancing. This type of system is becoming increasingly popular due to its ease of use.
In this case, the sweep system includes a combination reverse sweep receiver and forward data transmitter, which is located in the headend/hub. The frequency response characteristics of the received sweep signal (including relative amplitude and tilt) are converted by the headend sweep receiver to a data format, and transmitted in the forward RF path as a data carrier (by combining it into the forward headend combiner). The portable sweep generator/data receiver that is injecting the test signal into the RF launch amplifier's reverse path in the field is simultaneously receiving the incoming data carrier via the forward RF path. The incoming data is converted back to a sweep display that represents what is being received by the headend unit.
190
Reverse Balancing and Alignment Procedure
Overview
Digital Return technology is designed to have a constant link gain, regardless of the length of fiber or amount of passive optical loss in the link. That is, if the RF signal amplitude of all ports in all nodes is set to a constant value, the signal level at the output of the receiver will be balanced automatically to a constant power level.
Minor differences in levels can be trimmed out at the receiver with no penalty to link
Reverse Balancing the Node with EDR
performance.
Balancing and Alignment
Follow these steps to reverse balance and align the node with EDR.
1 Refer to the reverse system design print on the RF amplifier assembly cover and inject the proper level into the forward output test point of a port of the RF launch amplifier with a reverse sweep transmitter or a CW signal generator. The insertion loss of all forward output test points is 20 dB (relative to corresponding port).
Note: For the location of the forward output test point of each port, see RF
Important: To calculate the correct signal level to inject, add the reverse input level (from the design print) to the insertion loss of the forward output test point.
Formula:
Reverse input + Insertion loss = Signal generator setting
Example:
Reverse input = 15 dBmV
Insertion loss = 20 dB
Result: Signal generator setting=15 dBmV + 20 dB = 35 dBmV
Note: The ADC full-scale (100%) level for a single CW carrier is +33 dBmV. This is the level at which the ADC begins clipping.
Note: The reverse attenuator (pad) and reverse equalizer in the GS7000 Node is selected during the reverse system design, and it is based on the drive level into the digital module which is determined by system performance requirements, type and quantity of return carriers, etc. Consult data sheet to determine proper operational level.
2 Verify the level of the reverse output test point. This output level leaves the RF launch amplifier via the coaxial cable to the multiplexing digital module input.
(Use an SMB connector to F-connector test cable.)
3 Have the person in the headend refer to the headend system design and set the output of the receiver to the specified output level. See the instruction guide that was shipped with receiver for setup procedures.
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Troubleshooting
Equipment
The following equipment may be necessary to perform some troubleshooting procedures.
Cisco fiber optic ferrule cleaner, part number 468517, to clean fiber optic connectors
Cisco 99% alcohol and lint free wipes to clean fiber connectors
Optical power meter to measure light levels
Proper fiber connector for optical power meter to make optical connections
Digital voltmeter to measure voltages
Spectrum analyzer or a field strength meter to measure RF levels
Cisco test probe, part number 501111, to access test points
Cisco external test probe, part number 562580, to access external test points
192
Troubleshooting
Transmitter Module Troubleshooting Chart
Follow the steps in the table below to troubleshoot the transmitter module on LED signaling. The following steps indications and solutions apply to both EDR 1:1 and
2:1 transmitter modules.
Follow the steps in the table below to troubleshoot the transmitter module on LED signaling.
For EDR 1:1 Transmitter Module
Indication Possible Solutions LED Warning
PWR
OFF
LSR
OFF
Green
Green
Orange
(Solid)
Orange
(Blink)
No power supply.
Non-Cisco Standard OPM
Module is installed.
Input Level Overdrive.
Verify the power supply of the node with the transmitter installed.
Verify that connectors of the transmitter are clicked into the interface connectors in the transponder slot.
If still no power supply, contact the Cisco Technical Service Center for assistance.
No need for troubleshooting.
Cisco Standard OPM Module is highly recommended for better system performance and stability.
See the data sheet of the node for ordering information.
Verify the input level of RF port.
The output level overdrive indicates the output signal level exceeds the limit of 35 dBmV.
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For EDR 2:1 Transmitter Module
LED Warning
PWR
OFF
LSR
OFF
Green
Green
Orange
(Blink)
Orange
(Blink)
Orange
(Solid)
Orange
(Blink)
Green
Orange
(Solid)
Indication Possible Solutions
No power supply.
PWR
Non-Cisco Standard OPM
Module is installed.
Input Level Overdrive.
Non-Cisco Standard OPM
Module is in use.
Non-Cisco Standard OPM
Module is in use.
Output Level Overdrive.
Verify the power supply of the node with the transmitter installed.
Verify that connectors of the transmitter are clicked into the interface connectors in the transponder slot.
If still no power supply, contact the Cisco Technical Service Center for assistance.
No need for troubleshooting.
Cisco Standard OPM Module is highly recommended for better system performance and stability.
See the data sheet of the node for ordering information.
Verify the input level of RF port 2.
The output level overdrive indicates the output signal level exceeds the limit of 35 dBmV.
Verify the input level of RF port 1.
The output level overdrive indicates the output signal level exceeds the limit of 35 dBmV.
Verify the input level of RF port 1.
The output level overdrive indicates the output signal level exceeds the limit of 35 dBmV.
Cisco Standard OPM Module is highly recommended for better system performance and stability.
See the data sheet of the node for ordering information.
194
Orange
(Blink)
Orange
(Blink)
Troubleshooting
Non-Cisco Standard OPM
Module is in use.
Input Level Overdrive.
Verify the input level of RF port 1.
The output level overdrive indicates the output signal level exceeds the limit of 35 dBmV.
Verify the input level of RF port 1.
The output level overdrive indicates the output signal level exceeds the limit of 35 dBmV.
Cisco Standard OPM Module is highly recommended for better system performance and stability.
See the data sheet of the node for ordering information.
195
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Enhanced Digital Return Multiplexing Applications
Follow the steps in the table below to troubleshoot the transmitter module.
Symptom
No optical signal output
Possible Cause
Laser temperature could be too high or low.
Laser could be faulty.
Automatic power control circuit failure.
Damaged fiber.
Possible Solutions
Allow up to one minute after power is ON for the temperature to stabilize.
If still no output, contact the
Cisco Technical Service Center for assistance.
Contact the Cisco Technical
Service Center for assistance.
Contact the Cisco Technical
Service Center for assistance.
Contact the Cisco Technical
Service Center for assistance.
Symptom
No optical signal output
(cont'd)
Possible Cause
One or more power supply voltages are out of specification.
No AC at receptacle.
Possible Solutions
Check the power supply for proper operation.
Blown fuse on the power supply.
Faulty module.
Check the receptacle for AC power.
Check the power supply fuse and replace as necessary.
Contact the Cisco Technical
Service Center for assistance.
196
C
Appendix C
Expanded Fiber Tray
In This Appendix
Expanded Fiber Tray Overview ....................................................... 198
Expanded Fiber Tray Installation ..................................................... 200
Fiber Management System ................................................................ 203
Configuration Examples .................................................................... 209
Introduction
This appendix explains the installation and configuration of the
GS7000 Node expanded fiber tray.
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Expanded Fiber Tray
Expanded Fiber Tray Overview
Introduction
The expanded fiber tray is an optional replacement for the standard fiber tray in the
GS7000 Node. The expanded fiber tray provides additional space for fiber management/storage and the installation of additional bulkhead adaptors. The expanded fiber tray also provides the space for the installation of various passive devices such as CWDM and OADM cassettes and raw WDM cartridges.
Features
The expanded fiber tray provides the following features:
Design allows for configuration flexibility.
Built-in fiber guides and tabs aid management of slack fiber and maintenance of minimum bend radiuses.
Accommodates most commercially available optical passive devices.
Circular indexed slot pattern in tray base allows flexibility in mounting components.
Custom mounting clips provided to secure various components in tray.
Tray design facilitates additional securing of fibers and components with Velcro straps.
198
Expanded Fiber Tray Overview
Tray Components
The following illustration shows the unassembled expanded fiber tray components.
199
Appendix C
Expanded Fiber Tray
Expanded Fiber Tray Installation
Installation Procedure
Perform the following steps to install the expanded fiber tray in the node.
1 If you are replacing a standard fiber tray in an existing node, go to step 2.
If you are not replacing a standard fiber tray, go to step 3.
2 Remove any installed fibers from the existing standard fiber tray and then remove the fiber tray from the node by pulling up on the fiber tray assembly as shown in the following illustration.
200
3 Make sure that the expanded fiber tray clear cover is secured in place on the fiber tray.
4 Insert the expanded fiber tray part way into the node lid as shown in the following illustration.
Note: Push down on the cover at the cover locking tabs around the periphery of the fiber tray to secure the cover.
Expanded Fiber Tray Installation
Important:
Make sure that the fiber tray fits into the two guide slots in the fiber track near the power supplies.
Make sure that the fingers and locking tabs on the other end of the fiber tray are inserted between the fiber track and the aluminum node housing.
5 Push down on the fiber tray housing until the fiber tray snaps into place and is fully inserted into the node as shown in the following illustration.
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Appendix C
Expanded Fiber Tray
6 Pivot the fiber tray down and snap it into place on top of the power supplies with its locking tabs and in the node lid with its hold-down tab as shown in the following illustration.
202
Fiber Management System
Fiber Management System
Overview
The fiber management system is made up of a fiber tray and a fiber routing track.
The fiber tray provides a convenient location to mount passive devices and store excess fiber. The tray is hinged to allow it to move out of the way during the insertion of the fibers and for installation or replacement of the various node modules. The fiber routing track provides a channel for routing fiber pigtails to their appropriate optical modules as well as a location to snap in unused fiber connectors for storage.
The expanded fiber tray provides various clips to hold passive devices and bulkhead adaptors neatly in the tray while providing easy access. An indexed pattern of mounting slots in the tray allows you to install a variety of components in the tray in various configurations. Several features are incorporated into the tray to provide fiber protection and aid in maintaining the proper bend radius of the fiber. A sheet of blank, stick-on, labels is also included for use in identifying the installed components and configuration.
Quality fiber management focuses on four key areas, as follows:
Maintaining fiber bend radius
Proper fiber routing
Connectors and bulkhead access
Fiber protection
These topics are discussed in detail in the next sections.
Maintaining Fiber Bend Radius
Observe the following considerations regarding fiber bend radius:
Bent fibers can induce higher losses that can lead to signal degradation and service disruption.
Current industry standards call for a minimum bend radius of 1.5 inches (38 mm).
Using bend insensitive fiber, as defined in ITU-T G.657.A, can allow for a smaller bend radius. However, this does not diminish the need to control fiber bends.
The expanded fiber tray provides several guide walls for spooling and routing fiber. Use these guides to maintain the bend radius of the fiber.
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Expanded Fiber Tray
Proper Fiber Routing
Observe the following considerations regarding fiber routing:
Poor fiber routing is a major cause of bend radius violations.
Proper fiber routing provides well-defined paths, making it easier to access individual fibers.
Easy to follow paths aid technicians in performing fiber tracing, testing, and reconfiguration.
When fiber is not managed, slack fiber tends to become entangled, making tracing and rearrangement difficult.
The expanded fiber tray provides fiber guides to contain slack fiber. Slack fiber can be coiled in a circular fashion using the guides on the left side of the tray, or by routing through the guides on the outer edge of the tray.
204
The FIBER guides are designed to allow Velcro tie-down straps to be looped through the posts to further maintain neat fiber placement.
Fiber Management System
Connector and Bulkhead Access
Observe the following considerations regarding connector and bulkhead access:
Connector access is critical for reconfiguration, testing, maintenance, and troubleshooting.
The expanded fiber tray provides a clip which can accommodate up to four
SC-type bulkhead adapters, and a smaller clip which can hold up to two SC-type bulkhead adapters.
The clips can be placed in any one of the three circular retaining tracks in various orientations.
Fiber Protection
Observe the following considerations regarding fiber protection:
Fibers are subject to serious damage from mishandling that can cause pinching and bending of the fiber beyond its capabilities.
The expanded fiber tray comes with a clear protective cover. After fibers have been properly routed in the tray, the cover should be closed and locked in position with the locking tabs before stowing the tray in the node.
Always route fibers in the tray using the fiber guides located about the tray periphery. This will retain the fiber within the tray and prevent inadvertent displacement or pinching of the cable when opening or closing the node.
The mounting surface of the tray faces downward in the stowed position and upwards when the tray is in the access position, thereby discouraging inadvertent contact with the fibers and passive devices.
Passive Device and Bulkhead Mounting
Mounting clips are provided for installing available passive devices and bulkhead adaptors. These clips can be used to mount devices in various orientations in any of
205
Appendix C
Expanded Fiber Tray
the three circular retaining tracks in the expanded fiber tray. The following illustrations show the available mounting clips.
2-Adaptor Clip
The following illustration shows a 2-adaptor clip for bulkhead adaptors.
4-Adaptor Clip
The following illustration shows a 4-adaptor clip for bulkhead adaptors.
206
3-Cartridge Clip
The following illustration shows a 3-cartridge clip holding raw WDM cartridges.
Fiber Management System
CWDM Clip
The following illustration shows a CWDM clip.
Cassette Device Clip
The following illustration shows a cassette device clip holding a demultiplexer.
207
Appendix C
Expanded Fiber Tray
Fiber Installation
For general instructions on installing and routing the fiber optic cables in the node,
refer to the Fiber Optic Cable Installation (on page 74).
208
Configuration Examples
Configuration Examples
WDM Configuration Example
The following illustration shows a cartridge style WDM configuration of the expanded fiber tray.
This application is used to fully segment the GS7000 4-Port Node when limited fiber counts are available, or as means to conserve fibers for future use.
The GS7000 Node comes with several optical module options to help you combine
3x3, and 4x4 forward and return segments utilizing coarse wave division multiplexing (CWDM), dense wave division multiplexing (DWDM), and available analog or digital laser options.
With the use of four 1310 nm/1550 nm WDMs or four 1310 nm CWDMs installed in the node's expanded fiber tray, the 1310 nm forward path signals can be combined with the DWDM or CWDM return signals to achieve full 4x4 segmentation with half the quantity of fibers.
Note: This solution requires WDM modules at headend as shown in the following
209
Appendix C
Expanded Fiber Tray
illustration.
Headend
Fwd TX
Service Group 1
Rtrn RX
Service Group 1
Fwd TX
Service Group 2
Rtrn RX
Service Group 2
Fwd TX
Service Group 3
Rtrn RX
Service Group 3
Fwd TX
Service Group 4
Rtrn RX
Service Group 4
WDMs WDMs
GS7000 Node
Fwd RX
Service Group 1
Rtrn TX
Service Group 1
Fwd RX
Service Group 2
Rtrn TX
Service Group 2
Fwd RX
Service Group 3
Rtrn TX
Service Group 3
Fwd RX
Service Group 4
Rtrn TX
Service Group 4
Multi-Wave O-Band Demultiplexer Configuration Example
As the demand for bandwidth continues to grow and clusters of homes decrease into smaller serving areas, networks can become capacity constrained or ''fiber starved.''
A cost-effective approach to solving this problem uses multiple wavelengths on a single fiber.
The Prisma II™ Multi-Wavelength (O-Band) system solution enables dramatic bandwidth increase over a single optical fiber. This system uses forward transmitters capable of co-propagating multiple wavelengths in the 1320 nm to 1335 nm window down a single fiber using wavelength division multiplexing (WDM), with each transmitter carrying a full RF load.
The multi-wavelength solution is ideal for segmentation of node service areas because they enable the reuse of existing fiber up to six times, over distances of up to
30 kilometers.
210
Configuration Examples
The following illustration shows a cassette style O-Band demultiplexer configuration of the expanded fiber tray.
Using the O-Band demultiplexer in the expanded fiber tray, the four multiplexed
13xx multi-wave forward path signals are demultiplexed and feed into the four individual receiver modules to achieve 4x forward segmentation with a single fiber.
Note: This solution requires an O-Band multiplexer at the headend as shown in the following illustration.
211
Appendix C
Expanded Fiber Tray
212
Glossary
A
A ampere. A unit of measure for electrical current. ac, AC alternating current. An electric current that reverses its direction at regularly recurring intervals.
AC/RF alternating current radio frequency.
AFC automatic frequency control. An arrangement whereby the tuning of a circuit is automatically maintained within specified limits with respect to a reference frequency.
AGC automatic gain control. A process or means by which gain is automatically adjusted in a specified manner as a function of input level or other specified parameters.
AMPL amplitude. amplifier cascade two or more amplifiers in a series, the output of one feeding the input of another. attenuation
The difference between transmitted and received signal strength due to loss through equipment, lines, or other transmission medium. Usually expressed in decibels. attenuator
A passive device designed to reduce signal strength without distorting the waveform.
Usually specified in dB.
213
Glossary
AUX auxiliary.
B baseband
The original band of frequencies occupied by the signal before it modulates the carrier frequency to form the transmitted signal. Characteristic of any network technology that uses a single carrier frequency and requires all stations attached to the network to participate in every transmission. baud (Bd)
A measure of signaling rate based on the number of signaling events per unit of time. beamwidth
The included angle between two rays (usually the half-power points) on the radiation pattern, which includes the maximum lobe, of an antenna.
BIOS basic input/output system. blanking level
The amplitude of the front and back porches of the composite video signal. The blanking level separates the range containing picture information from the range containing synchronization information.
BNC
A coaxial connector that uses two bayonet lugs on the side of the female connector. BNC stands for Bayonet Neill Concelman and is named after Amphenol engineer Carl Concelman.
BPF bandpass filter.
BW bandwidth. A measure of the information-carrying capacity of a communications channel, for example the range of usable frequencies that can be carried by a CATV system. The bandwidth corresponds to the difference between the lowest and highest frequency that can be carried by the channel.
214
Glossary
C
C/N or CNR carrier-to-noise ratio. The ratio, in decibels, of the carrier to that of the noise in a receiver's IF bandwidth after specified band limiting and before any nonlinear process such as amplitude limiting and detection takes place.
C/T carrier-to-noise temperature ratio.
CISC
Complex Instruction Set Computer. A computer that uses many different types of instructions to conduct its operations, i.e., IBM PCs, Apple Macintosh’s, IBM 370 mainframes. compression
The non-linear change of gain at one level of a signal with respect to the change of gain at another level for the same signal. Also, the elimination of redundant information from an audio, data, or video signal to reduce transmission requirements.
CW continuous wave.
CWDM coarse wave-division multiplexing. CWDM allows a modest number of channels, typically eight or less, to be stacked in the 1550 nm region of the fiber called the C-Band. This capacity is greater than WDM (wave-division multiplexing) and lesser than DWDM (dense wave-division multiplexing).
D dB decibel. One tenth of a bel, the number of decibels denoting the ratio of two amounts of power being ten times the common logarithm of this ratio. dBc decibels relative to a reference carrier. dBi decibels of gain relative to an isotropic radiator.
215
Glossary
dBm decibels relative to 1 milliwatt. dBmV decibels relative to 1 millivolt. dBuV decibels relative to 1 microvolt. dBW decibels relative to 1 watt.
DC directional coupler. dc, DC direct current. An electric current flowing in one direction only and substantially constant in value. deviation
The peak difference between the instantaneous frequency of the modulated wave and the carrier frequency, in an FM system. differential gain
The difference in amplification of a signal (superimposed on a carrier) between two different levels of carrier. diplex filter
A filter which divides the frequency spectrum into a high frequency segment and a low frequency segment so that two different signals can be sent down the same transmission path. distribution
The activities associated with the movement of material, usually finished products or service parts, from the manufacturer to the customer. distribution system
The part of a CATV system consisting of the transmission medium (coaxial cables, fiber optic
216
Glossary
cables, etc.) used to carry signals from the headend system to subscriber terminals.
DSP digital signal processor. duplexer
A device which permits the connection of both a receiver and a transmitter to a common antenna.
DVM digital voltmeter.
DWDM dense wave-division multiplexing. A method of placing multiple wavelengths of light into a single fiber that yields higher bandwidth capacity. Dense WDM indicates close spacing and more than 4 to 8 wavelengths.
E
EC
European Community.
EEPROM electrically erasable programmable read-only memory.
EMC electromagnetic compatibility. A measure of equipment tolerance to external electromagnetic fields. emission designer
An FCC or CCIR code that defines the format of radiation from a transmitter.
EPROM erasable programmable read-only memory.
EQ equalizer.
217
Glossary
equalization
The process of compensating for an undesired result. For example, equalizing tilt in a distribution system.
ERP effective radiated power.
ESD electrostatic discharge. Discharge of stored static electricity that can damage electronic equipment and impair electrical circuitry, resulting in complete or intermittent failures.
F
FCM forward configuration module.
FET field-effect transistor. A transistor in which the conduction is due entirely to the flow of majority carriers through a conduction channel controlled by an electric field arising from a voltage applied between the gate and source electrodes.
FM frequency modulation. A transmission technique in which the frequency of the carrier varies in accordance with the modulating signal. frequency
The number of similar shapes in a communications or electrical path in a unit of time. For example, the number of sine waves moving past a fixed point in a second. frequency agile
The ability to change from one frequency to another without changing components. frequency response
The effect that changing the frequency has on the magnitude of a signal. ft-lb foot-pound. A measure of torque defined by the application of one pound of force on a lever at a point on the lever that is one foot from the pivot point.
218
ITU
L
LE
G gain
Glossary
H
Hertz
A measure of the increase in signal level, relative to a reference, in an amplifier. Usually expressed in decibels.
A unit of frequency equal to one cycle per second.
HFC hybrid fiber/coaxial. A network that uses a combination of fiber optics and coaxial cable to transport signals from one place to another. A broadband network using standard cable television transmission components, such as optical transmitters and receivers, coaxial cable, amplifiers, and power supplies. The broadband output stream is transmitted as an optical signal, over the high-speed, fiber optic transmission lines to local service areas where it is split, converted to electrical RF signals, and distributed to set-tops over coaxial cable.
I
I/O input/output.
IC integrated circuit.
IEC
International Electro-technical Commission.
IF intermediate frequency. The common frequency which is mixed with the frequency of a local oscillator to produce the outgoing radio frequency (RF) signal. in-lb inch-pound. A measure of torque defined by the application of one pound of force on a lever at a point on the lever that is one inch from the pivot point.
International Telecommunications Union. line extender.
219
Glossary
LED light-emitting diode. An electronic device that lights up when electricity passes through it.
LNC low-noise converter.
M
Mbps
O
N multipath, multipath transmission
The phenomenon which results from a signal traveling from point to point by more than one path so that several copies of the signal arrive at the destination at different times or at different angles.
Nm
Newton meter. A measure of torque defined by the application of one Newton of force on a lever at a point on the lever that is one meter from the pivot point. (1 Nm = 0.737561 ft-lb)
OIB optical interface board.
P
PCB printed circuit board.
PROM megabits per second. A unit of measure representing a rate of one million bits (megabits) per second. programmable read-only memory. A memory chip on which data can be written only once.
Once data has been written onto a PROM, it cannot be written to again.
PWB printed wiring board.
Q
QAM quadrature amplitude modulation. An amplitude and phase modulation technique for representing digital information and transmitting that data with minimal bandwidth. Both phase and amplitude of carrier waves are altered to represent the binary code. By manipulating two factors, more discrete digital states are possible and therefore larger binary
220
Glossary
schemes can be represented.
QPSK quadrature phase-shift keying. A phase modulation technique for representing digital information. QPSK produces four discrete states, each state representing two bits of information.
R
RCM reverse configuration module.
RCVR receiver. reverse path
Signal flow direction toward the headend.
RF radio frequency. The frequency in the portion of the electromagnetic spectrum that is above the audio frequencies and below the infrared frequencies, used in radio transmission systems.
RFI radio frequency interference.
RMA return material authorization. A form used to return products.
RX receive or receiver.
S
S/N or SNR signal-to-noise ratio. The ratio, in decibels, of the maximum peak-to-peak voltage of the video signal, including synchronizing pulse, to the root-mean-square voltage of the noise. Provides a measure and indication of signal quality.
SA system amplifier.
221
Glossary
SM status monitor.
SMC status monitoring and control. The process by which the operation, configuration, and performance of individual elements in a network or system are monitored and controlled from a central location.
SMIU status monitor interface unit.
SNMP
T synchronous transmission
A transmission mode in which the sending and receiving terminal equipment are operating continuously at the same rate and are maintained in a desired phase relationship. torque
A force that produces rotation or torsion. Usually expressed in lb-ft (pound-feet) or N-m
(Newton-meters). The application of one pound of force on a lever at a point on the lever that is one foot from the pivot point would produce 1 lb-ft of torque.
TX transmit or transmitter.
U
UPS un-interruptible power supply. uV simple network management protocol. A protocol that governs network management and the monitoring of network devices and their functions. microvolt. One millionth of a volt.
V
V volt.
222
W
W
Glossary
watt. A measure of electrical power required to do work at the rate of one joule per second. In a purely resistive load, 1 Watt = 1 Volt x 1 Amp.
223
Index
1
1 GHz Forward Linear Equalizers • 157
1x2 and 1x4 Forward Configuration Modules •
104
1x2 and 1x4 Forward Configuration Modules
Description • 29
1x2 and 1x4 Forward Configuration Modules with Forward RF Injection • 105
1x2 and 1x4 Forward Configuration Modules with Forward RF Injection Description • 29
1x2 and 1x4 Redundant Forward Configuration
Modules • 106
1x2 and 1x4 Redundant Forward Configuration
Modules Description • 30
1x2 and 1x4 Redundant Forward Configuration
Modules with Forward RF Injection • 107
1x2 and 1x4 Redundant Forward Configuration
Modules with Forward RF Injection
Description • 30
2
2x2 and 2x4 Forward Configuration Modules •
108
2x2 and 2x4 Forward Configuration Modules
Description • 31
2x2 and 2x4 Redundant Forward Configuration
Modules • 109
2x2 and 2x4 Redundant Forward Configuration
Modules Description • 31
3
3x4-1,2,4 Forward Configuration Module • 111
3x4-1,2,4 Forward Configuration Module
Description • 32
3x4-1,3,4 Forward Configuration Module • 110
3x4-1,3,4 Forward Configuration Module
Description • 32
4
4-Way Forward Path Signal Routing • 21
4-Way Forward Segmentable Node RF
Assembly • 95
4x1 Redundant Reverse Configuration Module •
115
4x1 Redundant Reverse Configuration Module
Description • 34
4x1 Reverse Configuration Module with
Auxiliary Reverse RF Injection • 114
4x1 Reverse Configuration Module with
Auxiliary Reverse RF Injection Description •
34
4x2 Redundant Reverse Configuration Module •
117
4x2 Redundant Reverse Configuration Module
Description • 35
4x2 Reverse Configuration Module with
Auxiliary Reverse RF Injection (8-Port OIB) •
116
4x2 Reverse Configuration Module with
Auxiliary Reverse RF Injection (8-Port OIB)
Description • 35
225
Index
4x3-1,2,4 Reverse Configuration Module with
Auxiliary Reverse RF Injection • 118
4x3-1,2,4 Reverse Configuration Module with
Auxiliary Reverse RF Injection Description •
36
4x3-1,3,4 Reverse Configuration Module with
Auxiliary Reverse RF Injection • 119
4x3-1,3,4 Reverse Configuration Module with
Auxiliary Reverse RF Injection Description •
36
4x4 Forward Configuration Module • 112
4x4 Forward Configuration Module Description
• 33
4x4 Reverse Configuration Module with
Auxiliary Reverse RF Injection • 120
4x4 Reverse Configuration Module with
Auxiliary Reverse RF Injection Description •
37
A
A • 213 ac, AC • 213
AC/RF • 213
Accessing the Receiver/Transmitter Module
Fiber Spool and Connector • 130
AFC • 213
AGC • 213
AMPL • 213 amplifier cascade • 213
Amplifier Output Linear Tilt Chart for 1 GHz •
155
Applying Power to the Node • 85 attenuation • 213
226 attenuator • 213
AUX • 214
B
baseband • 214 baud (Bd) • 214 beamwidth • 214
Before You Begin • 177
BIOS • 214 blanking level • 214
BNC • 214
BPF • 214
BW • 214
C
C/N or CNR • 215
C/T • 215
Care and Cleaning of Optical Connectors • 134
CISC • 215
Cleaning • 125
Closing the Housing • 122
Color Code • 74 compression • 215
Configuration Examples • 209
Connecting the RF Cables to the Node Housing •
84
Connector and Bulkhead Access • 205
Consumable Materials • 125
Customer Support Information • 151
CW • 215
CWDM • 215
D
dB • 215 dBc • 215 dBi • 215 dBm • 216 dBmV • 216 dBuV • 216 dBW • 216
DC • 216 dc, DC • 216
Description • 69, 72 deviation • 216 differential gain • 216 digital reverse troubleshooting • 192 diplex filter • 216 distribution • 216 distribution system • 216
DSP • 217 duplexer • 217
DVM • 217
DWDM • 217
E
EC • 217
EDR OPM and LCM • 176
EDR Receiver Module • 171
EDR Transmitter Module • 166
Index
EDR Transmitter Status Indicators • 187
EEPROM • 217
EMC • 217 emission designer • 217
Enhanced Digital Return (EDR) System
Installation • 177
Enhanced Digital Reverse System Overview •
159
EPROM • 217
EQ • 217 equalization • 218 equipment description • 2 features • 6
Equipment • 192
Equipment Description • 2
ERP • 218
ESD • 218
Expanded Fiber Tray Installation • 200
Expanded Fiber Tray Overview • 198
F
FCM • 218
Features • 6, 159, 198
FET • 218
Fiber Installation • 208
Fiber Management System • 75, 203 fiber optic cable care and cleaning of optical connectors • 134 installation • 74
227
Index
Fiber Optic Cable Installation • 74
Fiber Protection • 205
FM • 218
Forward Band Amplification 2-Way and 4-Way
Path Description • 25
Forward Configuration Module • 29 forward configuration modules configuration module replacement procedure
• 131 descriptions • 29
Forward Equalizer Chart • 156 forward path forward path setup procedure • 97 reconfiguring forward signal routing • 103
Forward Path • 21
Forward Path Setup Procedure • 97
Forward Routing Configurations • 103
Forward/Reverse Configuration Module,
Equalizer, and Node Signal Director
Replacement Procedure • 131 frequency • 218 frequency agile • 218 frequency response • 218 ft-lb • 218
Full Configuration • 162
Functional Description • 4
Functional Diagram
Hub Node • 20, 94
Functional Diagrams • 24
228
4-Way Forward Segmentable Node • 17, 91
G
gain • 219
General Information • 1
H
Hertz • 219
HFC • 219 housing opening and closing • 122 pedestal or wall mounting • 72 strand mounting • 69
I
I/O • 219
IC • 219
IEC • 219
IF • 219 in-lb • 219 installation of fiber optic cables • 74 of RF cables • 82 pedestal or wall mounting the node • 72 strand mounting the node • 69 tools and test equipment • 66
Installation • 65
Installation Procedure • 200
Installing the EDR Receiver • 185
Installing the EDR Transmitter • 178
Introduction • 21, 22, 23, 24, 29, 34, 97, 101,
103, 113, 189, 198, 212
ITU • 219
L
LE • 219
LED • 220
Linear Tilt Chart • 154
LNC • 220 local control module • 58
Local Control Module Description • 59
M
Maintaining Fiber Bend Radius • 203 maintenance • 121
Maintenance • 121
Mbps • 220
Method of Generating and Monitoring Test
Signals • 189
Module Replacement Procedure • 127 modules functional descriptions • 7 removing and replacing modules • 127
Modules Functional Descriptions • 7 multipath, multipath transmission • 220
Multi-Wave O-Band Demultiplexer
Configuration Example • 210
N
Nm • 220
No RF Output
Fiber Optic Light Level is Good, Receiver
Optical Power LED is On • 142
Index
Optical Power LED on Receiver Module is
Off • 140
No RF Output from Reverse Receiver • 150 node opening and closing • 122
Node Fastener Torque Specifications • 66
Node Housing Ports • 68
Node Inputs/Outputs Diagram • 7
Node Power Limitations • 63
Node Powering Procedure • 85
Notes • 141, 143, 145, 147, 149
O
OIB • 220
Opening and Closing the Housing • 122
Opening the Housing • 122
Operating Environment • 177
Optical Amplifier (EDFA) Modules • 45
Optical Amplifier and Optical Switch Module
Pin Adaptor • 128
Optical Amplifier Module Descriptions • 45
Optical Amplifier Module Diagram • 47
Optical Amplifier Operating Parameters • 47 optical connectors care and cleaning of optical connectors • 134
Optical Interface Board (OIB) • 38
Optical Interface Board Description • 38 optical receiver module • 39
Optical Receiver Module • 39
Optical Receiver Module Description • 39
229
Index
Optical Receiver Module Diagram • 42
Optical Switch Module • 52
Optical Switch Module Description • 52
Optical Switch Module Diagram • 53
Optical Switch Operating Parameters • 53 optical transmitter module • 43
Optical Transmitter Module Descriptions • 43
Optical Transmitter Module Diagram • 44
Optical Transmitter Modules • 43
Optical Transmitter Setup Procedure • 101
Ordering Matrix • 13
Overview • 2, 58, 74, 82, 85, 122, 124, 127, 203
P
Passive Device and Bulkhead Mounting • 205
PCB • 220
Pedestal or Wall Mounting the Node • 72
Physical Description • 2
Poor C/N Performance • 144
Poor Distortion Performance • 146
Poor Frequency Response • 148 power distribution • 23
Power Distribution • 23 power supply module • 61
Power Supply Module • 61
Power Supply Module Description • 61 powering the node • 85
Preventative Maintenance • 124
Procedure • 69, 72, 77, 125
230
PROM • 220
Proper Fiber Routing • 204
PWB • 220
Q
QAM • 220
QPSK • 221
R
RCM • 221
RCVR • 221
Receiver Operating Modes • 173
Recommended Equipment • 134
Reconfiguring Forward Signal Routing • 103
Reconfiguring Reverse Signal Routing • 113
Removing and Replacing Modules • 127
Required Tools and Test Equipment • 66, 90
Reverse Balancing and Alignment Procedure •
190
Reverse Balancing the Node with EDR • 189
Reverse Band Amplification Path Description •
27
Reverse Configuration Module • 34 reverse configuration modules configuration module replacement procedure
• 131 descriptions • 34 reverse path • 221 reconfiguring reverse signal routing • 113 reverse path setup procedures • 101 reverse path signal routing • 22
Reverse Path • 22
Reverse Path Setup Procedure • 101
Reverse Path Signal Routing • 22
Reverse Routing Configurations • 113
RF • 221
RF Amplifier Assembly Replacement Procedure
• 131
RF amplifier module forward band amplification path description •
25 functional diagrams • 24 reverse band amplification path description •
27
RF Amplifier Module • 24
RF Assembly • 95
RF cable installation • 82 trimming the center conductor • 82
RF Cable Installation • 82
RFI • 221
RMA • 221
RX • 221
S
S/N or SNR • 221
SA • 221
Schedule • 124 setup and operation • 89 forward path setup procedure • 97 reverse path setup procedures • 101 tools and test equipment • 90
Index
Setup and Operation • 89
Setup Procedure • 97
Single Transmitter Configuration • 160
SM • 222
SMC • 222
SMIU • 222
SNMP • 222 status monitor • 58
Status Monitor Description • 58
Status Monitor/Local Control Module • 58
Strand Mounting the Node • 69 synchronous transmission • 222
System Block Diagram • 164
System Diagrams • 17, 91
System Functional Diagrams • 160
T
Theory of Operation • 15
Tips for Optimal Fiber-Optic Connector
Performance • 134
To Clean Optical Connectors • 135
Tools and Test Equipment • 66, 90 torque • 222
Transmitter Module Setup Procedure • 186
Transmitter Module Troubleshooting Chart • 193
Tray Components • 199
Trimming the Center Conductor • 82
Troubleshooting • 139, 192
Troubleshooting Flowchart • 140, 142, 144, 146,
148, 150
231
Index
troubleshooting flowcharts • 139
TX • 222
U
UPS • 222 uV • 222
V
V • 222
Visual Inspection • 124
Voltage Check Procedure • 86
W
W • 223
WDM Configuration Example • 209
232
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© 2015 Cisco Systems, Inc. All rights reserved.
October 2015 Printed in United States of America First Published: October 2015
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