Comtech EF Data DMDVR20 LBST User Manual

DMDVR20 LBST

L-Band Satellite Modulator

Industry Standard LDPC Receiver

and ODU Driver

Installation and Operation Manual

TM136

Revision 1.1

Radyne Corporation • 3138 E. Elwood St. • Phoenix, AZ 85034 • [phone] • Fax: [phone] • www.radn.com

DMDVR20 LBST Satellite Modem Warranty Policy

Warranty Policy

WP

Radyne Corp. (Seller) warrants the items manufactured and sold by Radyne Corp. to be free of
defects in material and workmanship for a period of two (2) years from date of shipment Radyne
Corp.’s obligation under its warranty is limited in accordance with the periods of time and all other
conditions stated in all provisions of this warranty.

This warranty applies only to defects in material and workmanship in products manufactured by
Radyne Corp. Radyne Corp. makes no warranty whatsoever concerning products or accessories
not of its manufacture. Repair, or at the option of Radyne Corp., replacement of the Radyne
Corp. products or defective parts therein shall be the sole and exclusive remedy for all valid
warranty claims.

Warranty Period

The applicable warranty period shall commence on the date of shipment from a Radyne Corp.
facility to the original purchaser and extend for the stated period following the date of shipment.
Upon beginning of the applicable Radyne Corp. warranty period, all customers’ remedies shall be
governed by the terms stated or referenced in this warranty. In-warranty repaired or replacement
products or parts are warranted only for the remaining unexpired portion of the original warranty
period applicable to the repaired or replaced products or parts. Repair or replacement of
products or parts under warranty does not extend the original warranty period.

Warranty Coverage Limitations

The following are expressly not covered under warranty:

1. Any loss, damage and/or malfunction relating in any way to shipping, storage, accident,
abuse, alteration, misuse, neglect, failure to use products under normal operating
conditions, failure to use products according to any operating instructions provided by
Radyne Corp., lack of routine care and maintenance as indicated in any operating
maintenance instructions, or failure to use or take any proper precautions under the
circumstances.

2. Products, items, parts, accessories, subassemblies, or components which are
expendable in normal use or are of limited life, such as but not limited to, bulbs, fuses,
lamps, glassware, etc. Radyne Corp. reserves the right to revise the foregoing list of
what is covered under this warranty.

Warranty Replacement and Adjustment

Radyne Corp. will not make warranty adjustments for failures of products or parts, which occur
after the specified maximum adjustment period. Unless otherwise agreed, failure shall be
deemed to have occurred no more than seven (7) working days before the first date on which
Radyne Corp. receives a notice of failure. Under no circumstances shall any warranty exceed the
period stated above unless expressly agreed to in writing by Radyne Corp.

Liability Limitations

This warranty is expressly in lieu of and excludes all other express and implied warranties,
Including but not limited to warranties of merchantability and of fitness for particular purpose, use,

TM136 – Rev. 1.1 iii

Warranty Policy DMDVR20 LBST Satellite Modem

or applications, and all other obligations or liabilities on the part of Radyne Corp., unless such
other warranties, obligations, or liabilities are expressly agreed to in writing by Radyne Corp.

All obligations of Radyne Corp. under this warranty shall cease in the event its products or parts
thereof have been subjected to accident, abuse, alteration, misuse or neglect, or which have not
been operated and maintained in accordance with proper operating instructions.

In no event shall Radyne Corp. be liable for Incidental, consequential, special or resulting loss or
damage of any kind howsoever caused. Radyne Corp.’s liability for damages shall not exceed
the payment, if any, received by Radyne Corp. for the unit or product or service furnished or to be
furnished, as the case may be, which is the subject of claim or dispute.

Statements made by any person, including representatives of Radyne Corp., which are
inconsistent or in conflict with the terms of this warranty, shall not be binding upon Radyne Corp.
unless reduced to writing and approved by an officer of Radyne Corp.

Warranty Repair Return Procedure

Before a warranty repair can be accomplished, a Repair Authorization must be received. It is at
this time that Radyne Corp. will authorize the product or part to be returned to the Radyne Corp.
facility or if field repair will be accomplished. The Repair Authorization may be requested in
writing or by calling:

Radyne Corp.

3138 E. Elwood St.
Phoenix, Arizona 85034 (USA)
ATTN: Customer Support
Phone: [phone]
Fax: [phone]

Any product returned to Radyne Corp. for examination must be sent prepaid via the means of
transportation indicated as acceptable to Radyne Corp. Return Authorization Number must be
clearly marked on the shipping label. Returned products or parts should be carefully packaged in
the original container, if possible, and unless otherwise indicated, shipped to the above address.

Non-Warranty Repair

When a product is returned for any reason, Customer and its shipping agency shall be
responsible for all damage resulting from improper packing and handling, and for loss in transit,
not withstanding any defect or nonconformity in the product. By returning a product, the owner
grants Radyne Corp. permission to open and disassemble the product as required for evaluation.
In all cases, Radyne Corp. has sole responsibility for determining the cause and nature of failure,
and Radyne Corp.’s determination with regard thereto shall be final.

iv TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Preface

Preface

P

This manual provides installation and operation information for the Radyne DMDVR20 LBST.
This is a technical document intended for use by engineers, technicians, and operators
responsible for the operation and maintenance of the DMDVR20 LBST.

Conventions

Whenever the information within this manual instructs the operator to press a pushbutton switch
or keypad key on the Front Panel, the pushbutton or key label will be shown enclosed in "less
than" (<) and "greater than" (>) brackets. For example, the Reset Alarms Pushbutton will be
shown as <RESET ALARMS>, while a command that calls for the entry of a ‘7’ followed by
‘ENTER’ Key will be represented as <7,ENTER>.

Cautions and Warnings

A caution icon indicates a hazardous situation that if not avoided, may result in minor or moderate
injury. Caution may also be used to indicate other unsafe practices or risks of property damage.

A warning icon indicates a potentially hazardous situation that if not avoided, could result in death
or serious injury.

A note icon identifies information for the proper operation of your equipment, including helpful
hints, shortcuts, or important reminders.

TM136 – Rev. 1.1 v

Preface DMDVR20 LBST Satellite Modem

Trademarks

Product names mentioned in this manual may be trademarks or registered trademarks of their
respective companies and are hereby acknowledged.

Copyright

©2008, Radyne Corp. This manual is proprietary to Radyne Corp. and is intended for the
exclusive use of Radyne Corp.’s customers. No part of this document may in whole or in part, be
copied, reproduced, distributed, translated or reduced to any electronic or magnetic storage
medium without the express written consent of a duly authorized officer of Radyne Corp.

Disclaimer

This manual has been thoroughly reviewed for accuracy. All statements, technical information,
and recommendations contained herein and in any guides or related documents are believed
reliable, but the accuracy and completeness thereof are not guaranteed or warranted, and they
are not intended to be, nor should they be understood to be, representations or warranties
concerning the products described. Radyne Corp. assumes no responsibility for use of any
circuitry other than the circuitry employed in Radyne Corp. systems and equipment. Furthermore,
since Radyne Corp. is constantly improving its products, reserves the right to make changes in
the specifications of products, or in this manual at any time without notice and without obligation
to notify any person of such changes.

Record of Revisions

Revision

Date Reason for Change

Level

1.0 2-19-08 Initial Release

1.1 5-5-08 Correct front panel menus, Various other changes.

Comments or Suggestions Concerning this Manual

Comments or suggestions regarding the content and design of this manual are appreciated. To
submit comments, please contact the Radyne Corp. Customer Service Department.

vi TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Table of Contents

Table of Contents

To C

Section 1 - Introduction ...............................................................................................1-1

1.0 Overview ______________________________________________________________ 1-1

1.1 Features/Options Installed at Time of Order ___________________________________ 1-2

1.1.1 Feature Upgrades ______________________________________________________ 1-2

1.1.2 Radyne Installed Options ________________________________________________ 1-2

1.1.3 Hardware Options ______________________________________________________ 1-2

1.2 Function Accessibility_____________________________________________________ 1-2

Section 2 - Installation ................................................................................................. 2-1

2.0 Installation Requirements__________________________________________________ 2-1

2.1 Unpacking _____________________________________________________________ 2-2

2.2 Removal and Assembly ___________________________________________________ 2-2

2.3 Mounting Considerations __________________________________________________ 2-3

2.4 Initial Configuration Check _________________________________________________ 2-3

2.5 Modulator Checkout ______________________________________________________ 2-5

2.5.1 Initial Power-Up________________________________________________________ 2-5

2.5.2 Factory Terminal Setup __________________________________________________ 2-5

2.6 Storage________________________________________________________________ 2-5

Section 3 - Theory of Operation..................................................................................3-1

3.0 Modem Hardware________________________________________________________ 3-1

3.0.1 L-Band/IF Printed Circuit Card ____________________________________________ 3-1

3.0.2 Baseband Processing Printed Circuit Card ___________________________________ 3-2

3.0.3 Enhanced Interface Printed Circuit Card_____________________________________ 3-3

3.1 Functional Block Diagram _________________________________________________ 3-3

3.1.1 Front Panel ___________________________________________________________ 3-4

3.1.2 Baseband Processing ___________________________________________________ 3-4

3.1.3 Tx Baseband Processing ________________________________________________ 3-5

3.1.4 Rx Baseband Processing ________________________________________________ 3-5

3.2 Monitor & Control (M&C) Subsystem _________________________________________ 3-5

3.2.1 Terminal Port__________________________________________________________ 3-6

TM136 – Rev. 1.0 vii

Table of Contents DMDVR20 LBST Satellite Modem

3.2.2 Modem Remote Communications (RLLP)____________________________________ 3-6

3.2.3 Ethernet M&C Port _____________________________________________________ 3-6

3.2.4 Modem Monitor Status __________________________________________________ 3-6

3.3 Internal Clock ___________________________________________________________ 3-7

3.4 Loopback Features (Terrestrial)_____________________________________________ 3-8

3.5 Clocking Options _______________________________________________________ 3-10

3.5.1 TX Clock Options _____________________________________________________ 3-10

3.5.1.1 SCTE: Serial Clock Transmit External ____________________________________ 3-11

3.5.1.2 SCT: Serial Clock Transmit ____________________________________________ 3-11

3.5.2 RX Buffer Clock Options ________________________________________________ 3-11

3.5.2.1 RX Sat Clock _______________________________________________________ 3-12

3.5.3 EXT REF: External Reference, Top BNC Port, J10 ___________________________ 3-12

3.6 RS530/422/V.35 Interface (Standard) _______________________________________ 3-12

3.7 Reed-Solomon Codec (TX Only) ___________________________________________ 3-13

3.7.1 Reed-Solomon Operation _______________________________________________ 3-13

3.7.2 Reed-Solomon Code Rate ______________________________________________ 3-13

3.7.3 Interleaving __________________________________________________________ 3-13

3.8 Locating the ID Code Operational Procedure__________________________________ 3-15

3.9 Strap Codes (TX Only Option) _____________________________________________ 3-15

Section 4 - User Interfaces ..........................................................................................4-1

4.0 User Interfaces__________________________________________________________ 4-1

4.1 Front Panel User Interface _________________________________________________ 4-1

4.1.1 LCD Front Panel Display_________________________________________________ 4-2

4.1.2 Cursor Control Arrow Keys _______________________________________________ 4-2

4.1.3 Numeric Keypad _______________________________________________________ 4-2

4.1.4 Front Panel LED Indicators _______________________________________________ 4-3

4.2 Parameter Setup ________________________________________________________ 4-4

4.3 Front Panel Control Screen Menus __________________________________________ 4-4

4.3.1 Main Menus___________________________________________________________ 4-4

4.3.2 Modula

4.3.3 Demodulator Menu Options and Parameters _________________________________ 4-9

tor Menu Options and Parameters____________________________________ 4-5

4.3.4 Interface Menu Options and Parameters____________________________________ 4-12

4.3.5 Monitor Menu Options and Parameters_____________________________________ 4-15

4.3.6 Alarms Menu Options and Parameters _____________________________________ 4-17

4.3.7 System Menu Options and Parameters_____________________________________ 4-23

4.3.8 Test Menu Options and Parameters _______________________________________ 4-28

viii TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Table of Contents

4.4 Terminal Mode Control___________________________________________________ 4-30

4.4.1 Modem Terminal Mode Control___________________________________________ 4-30

4.4.2 Modem Setup for Terminal Mode _________________________________________ 4-30

4.5 Terminal Port User Interface ______________________________________________ 4-31

4.6 Connecting the Terminal _________________________________________________ 4-31

4.7 Terminal Screens _______________________________________________________ 4-31

Section 5 - Rear Panel Interfaces ...............................................................................5-1

5.0 DMDVR20 LBST Connections ______________________________________________ 5-1

5.1 Compact Flash __________________________________________________________ 5-1

5.2 Power Input Modules _____________________________________________________ 5-2

5.2.1 AC Power Input Module _________________________________________________ 5-2

5.3 DMDVR20 LBST Chassis Connections _______________________________________ 5-2

5.3.1 EXT REF (J10) ________________________________________________________ 5-2

5.3.2 TX L-Band IF (J11) _____________________________________________________ 5-2

5.3.3 RX (J1) ______________________________________________________________ 5-2

5.3.4 ALARM (J15)__________________________________________________________ 5-2

5.3.5 EXT CLK (J16) ________________________________________________________ 5-3

5.3.6 ASYNC (J17) (NOT SUPPORTED)_________________________________________ 5-3

5.3.7 (J18) ________________________________________________________________ 5-3

5.3.8 EIA-530 (J19) _________________________________________________________ 5-4

5.3.9 REMOTE (J20) ________________________________________________________ 5-5

5.3.10 ETHERNET (J21) (FUTURE OPTION) _____________________________________ 5-5

Section 6 - Maintenance and Troubleshooting .........................................................6-1

6.0 Periodic Maintenance_____________________________________________________ 6-1

6.0.1 Clock Adjustment ______________________________________________________ 6-1

6.1 Troubl

6.1.1 Alarm Faults

6.1.1.1 Major Tx Alarms

6.1.1.2 Major Rx Alarms

6.1.1.3 Minor Tx Alarms

eshooting _________________________________________________________ 6-1

__________________________________________________________ 6-2

______________________________________________________ 6-2

______________________________________________________ 6-3

______________________________________________________ 6-3

6.1.1.4 Minor Rx Alarms

6.1.1.5 Com

6.2 Alarm Masks

6.2.1 Active Alarms

6.2.1.1 Major Alarms

TM136 – Rev. 1.0 ix

mon Major Alarms_________________________________________________ 6-4

____________________________________________________________ 6-5

______________________________________________________ 6-4

_________________________________________________________ 6-5

________________________________________________________ 6-5

Table of Contents DMDVR20 LBST Satellite Modem

6.2.1.2 Minor Alarms ________________________________________________________ 6-5

6.2.1.3 Common Equipment Faults _____________________________________________ 6-5

6.2.2 Latche

d Alarms ________________________________________________________ 6-5

Section 7 - Technical Specifications ..........................................................................7-1

7.0 Data Rates _____________________________________________________________ 7-1

7.1 Modulator ______________________________________________________________ 7-1

7.2 Demod

7.3 Monitor a

7.4 Terrestri

7.5 IBS/Synchron

7.6 Environ

7.7 Physical

7.8 DMDVR20 LBST Modulator Data Rate Limits __________________________________ 7-4

7.8.1 Closed Net Data Rate Limits ______________________________________________ 7-4

7.9 DMDVR20 LBST Demodulator Specifications __________________________________ 7-6

7.9 Data Rates (DSS-S2)_____________________________________________________ 7-6

7.10 BER Performance (LDPC) ________________________________________________ 7-7

ulator____________________________________________________________ 7-2

nd Control ______________________________________________________ 7-2

al Interfaces _____________________________________________________ 7-3

ous Interface (Standard)________________________________________ 7-3

mental __________________________________________________________ 7-3

_______________________________________________________________ 7-3

Appendix A - Product Options................................................................................... A-1

A.0 Hardware Options _______________________________________________________ A-1

A.0.1 Internal High Stability ___________________________________________________ A-1

A.0.2 DC Inp

A.0.3 Turbo

A.1 Customi

ut Prime Power __________________________________________________ A-1

Product Codec / Variable Reed-Solomon_______________________________ A-1

zed Options______________________________________________________ A-1

Appendix B - Front Panel Upgrade Procedure......................................................... B-1

B.0 Introduction ____________________________________________________________ B-1

B.1 Required Equipment _____________________________________________________ B-1

B.2 Upgra

B.3 Demon

B.3.1 Runnin

B.3.2 Cancel

de Procedure ______________________________________________________ B-1

stration Procedure _________________________________________________ B-3

g in Demonstration Mode __________________________________________ B-5

ing Demonstration Mode ___________________________________________ B-6

x TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Table of Contents

Appendix C - Carrier Control ..................................................................................... C-1

C.0 States_________________________________________________________________ C-1

C.1 Carrier Off _____________________________________________________________ C-1

C.2 Ca

C.3 Ca

C.4 Ca

C.5 Ca

rrier On _____________________________________________________________ C-1

rrier Auto ____________________________________________________________ C-1

rrier VSat____________________________________________________________ C-1

rrier RTS ____________________________________________________________ C-2

Appendix D - Strap Codes.......................................................................................... D-1

D.0 Strap Codes for Modulator Only ____________________________________________ D-1

D.1 Sample Applications _____________________________________________________ D-4

D.1.1 Operational Case Examples ______________________________________________ D-5

Glossary....................................................................................................................... G-1

TM136 – Rev. 1.0 xi

Table of Contents DMDVR20 LBST Satellite Modem

xii TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Introduction

Introduction

1

This chapter provides an overview of the DMDVR20 LBST Satellite Modem. The DMDVR20
LBST will be referred to in this manual as “the standard unit” and the DMDVR20 LBST will be
referred to as the LBST. When describing the DMDVR20 LBST, it may be referred to as “the
DMDVR20 LBST”, “the modem”, or “the unit”.

1.0 Overview

The Radyne DMDVR20 LBST Satellite Modem (Figure 1-1) offers the best features of a
sophisticated programmable modem.

Figure 1-1. DMDVR20 LBST Satellite Modem Front Panel

This versatile equipment package combines unsurpassed performance with numerous user­friendly Front Panel Programmable Functions. The DMDVR20 LBST provides different services
for the modulator and the demodulator. The modulator supported services are: Closed net,
Intelsat IBS and LDPC Receiver. All of the configuration and Monitor and Control (M&C)
Functions are available at the Front Panel. Operating parameters, such as variable data rates,
FEC Code Rate, modulation type, IF Frequencies, Framing and interface type can be readily set
and changed at the Front Panel by earth station operations personnel.

The modulator operates at all standard IBS Data Rates up to 8.448 Mbps. Selection of any data
rate is provided over the range of 2.4 Kbps to 20 Mbps in 1 bps steps. The Demodulator
supports LDPC Broadcast Services. The LDPC supports QPSK, 8PSK and 16APSK applications
with symbol rates of 2 to 20 Msps. Standard Interface available on the unit is RS422/530.

The DMDVR20 LBST offers additional features that serves as an interface between the indoor
unit (DMDVR20 LBST) and the outdoor units (consisting of the BUC and LNB). The output
frequency of the LBST is 950 to 2050 MHz. The LBST TX port can supply voltage, 10 MHz
Reference and FSK to the BUC via the IFL cable. The RX port can supply LNB via the IFL Cable.
The BUC voltage supplied to the BUC can either be 24 or 48 Volts. The Rx Port LNB voltage
consists of 18 volts.

The LBST has the capability to enable and disable the BUC/LNB voltages and 10 MHz reference
via the front panel. In addition, monitoring features provide verification of system status. The
LBST monitors both the current and the voltage at the output of the Tx Port, thus allowing the
user to monitor the status of both the indoor units and outdoor units.

TM136 – Rev. 1.1 1-1

Introduction DMDVR20 LBST Satellite Modem

1.1 Features/Options Installed at Time of Order

The DMDVR20 LBST can be configured in the following different ways:

• features and options that are installed when the unit is ordered

• feature upgrades

• hardware options that are installed to a unit that is sent to a Radyne facility

• hardware options that the user can install at their own location

Features installed at the time of ordering are the options pre-installed/initialized in the factory prior
to shipment. These can be reviewed from the front panel system menu. Refer to Section 4, User
Interfaces for information on how to view these features.

Factory installed options are chassis and board configurations that are introduced during
manufacturing.

1.1.1 Feature Upgrades

Feature Upgrades are soft upgrades that can be easily be enabled on the modem. Enabling new
features are done remotely or through the front panel of the modem. Features may be purchased
at any time by contacting a Radyne Corp. salesperson. Refer to Section 4 and Appendix D, for
information on how upgrade features are enabled.

1.1.2 Radyne Installed Options

Units may also be sent to the Radyne Corp. facility for hardware option installation. Please
contact the Radyne Corp. Customer Service Department for information pertaining to availability
and to shipping costs.

1.1.3 Hardware Options

Hardware options (refer to Appendix A) are purchased parts that can be installed into the unit at
the customer’s site. A screwdriver is normally the only tool required. Please contact the Radyne
Corp. Customer Service Department for information pertaining to availability and to shipping
costs.

Only authorized service personnel should handle and install optional
hardware options.

1.2 Function Accessibility

All functions can be accessed through the front panel, terminal or personal computer via a serial
link or via the Ethernet port offering a complete remote monitoring and control capability.

1-2 TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Introduction

TM136 – Rev. 1.1 1-3

DMDVR20 LBST Satellite Modem Installation

Installation

2

This section provides unpacking and installation instructions, and a description of external
connections and backward alarm information.

2.0 Installation Requirements

The DMDVR20 LBST Modem is designed to be installed within any standard 19-inch (48.26 cm)
wide equipment cabinet or rack. It requires one rack unit (RU) of mounting space (1.75
inches/4.45 cm) vertically and 19.25 inches (48.89 cm) of depth for the DMDVR20 LBST and 24
inches (60.96 cm) of depth for the DMDVR20 LBST. The rear panel of the modem is has power
entering from the left and IF Cabling entering from the right (as viewed from the rear of the unit).
Data and Control Cabling can enter from either side.

PROPER GROUNDING PROTECTION: During installation and setup, the
user must ensure that the unit is properly grounded. The equipment
shall be connected to the protective earth connection through the end
use protective earth protection.

In addition, the IF input and output coax cable shielding must be properly
terminated to the Chassis/unit ground

There are no user-serviceable parts or configuration settings located
inside the Chassis. There is a potential shock hazard internally at the
power supply module. DO NOT open the Chassis under any
circumstances.

TM136 – Rev. 1.1 2-1

Installation DMDVR20 LBST Satellite Modem

Before initially applying power to the unit, it is a good idea to disconnect
the transmit output from the operating ground station equipment. This is
especially true if the current configuration settings are unknown, where
incorrect settings could disrupt existing communications traffic.

The modem contains a Lithium Battery. DANGER OF EXPLOSION exists
if the battery is incorrectly replaced. Replace only with the same or
equivalent type recommended by the manufacturer. Dispose of used
batteries in accordance with local and national regulations.

2.1 Unpacking

The Universal Satellite Modem was carefully packaged to avoid damage and should arrive
complete with the following items for proper installation:

 Modem Unit
 Power Cord, with applicable AC Connector
 Installation and Operation Manual

2.2 Removal and Assembly

The Modem is shipped fully assembled. It does not require removal of the covers for any
purpose in installation.

Always ensure that power is removed from the before removing or
installing any optional modules. Failure to do so may cause damage to
the equipment.

Carefully unpack the unit and ensure that all of the above items are in the carton. If the available
AC mains power at the installation site requires a different cord set from the one included in the
package, then a suitable and approved cord set (for the country where the equipment is to be
installed) will be required before proceeding with the installation.

2-2 TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Installation

Should the Power Cable/AC Connector be of the wrong type for the installation, either the cable
or the power connector end should be replaced. The power supply itself is designed for universal
AC application. See specifications for appropriate voltages and currents.

2.3 Mounting Considerations

When mounted in an equipment rack, adequate ventilation must be provided. The ambient
temperature in the rack should preferably be between 10° and 35°C, and held constant for best
equipment operation. The air available to the rack should be clean and relatively dry. The
modems may be stacked one on top of the other to a maximum of 10 consecutive units before
providing one (1) RU of space for airflow. Modems should not be placed immediately above a
high-heat or EMF Generator to ensure the output signal integrity and proper receive operation.

Do not mount the in an unprotected outdoor location where there is direct contact with rain, snow,
wind or sun. The only tools required for rack mounting are four (4) customer supplied rack­mounting screws and the appropriate screwdriver. Rack mounting brackets are an integral part of
the front bezel of the unit and are not removable.

2.4 Initial Configuration Check

The modem is shipped from the factory with preset factory defaults. Upon initial power-up, a user
check should be performed to verify the shipped modem configuration. Refer to Section 4, User
Interfaces to locate and verify that the following configuration settings are correct:

The Interface Type (V.35, RS-422, RS-232, etc.) MUST be selected from the
Front Panel BEFORE the mating connectors are installed. Failure to do so
may cause damage to the Universal Interface Module. Power up the
modem, select the appropriate interface type, and then install the mating
connectors.

Transmit (Tx) and Receive (Rx) Interface types are dependent upon the
customer’s order.

TM136 – Rev. 1.1 2-3

Installation DMDVR20 LBST Satellite Modem

Standard Factory Configuration Settings

Modulator:

Data Rate: 2.048 Mbps
Mode: Closed Network
Frequency: 1200 MHz
Modulation: QPSK
Inner FEC: 1/2 Rate Viterbi
Satellite Framing: None
Scrambler: V.35 (IESS)
Reed Solomon: Disabled
Modulator Output Power: -20 dBm

Demodulator:

Data Rate: 2.048 Mbps
Mode: DSS
Frequency: 1200 MHz
Modulation: QPSK
Inner FEC: 1/2 Rate LDPC
Satellite Framing: S2 Short
Terrestrial Framing: None
Pilot Symbols: Disabled

Usage of the modems loopback capabilities in conjunction with the

Ethernet data interface can produce undesirable network loops. In order

to run any type of data test with an Ethernet interface you must utilize

two modems connected back to back. Simply using one modem and a

loopback will not produce the desired results.

2-4 TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Installation

2.5 Modulator Checkout

The following descriptions assume that the modem is installed in a suitable location with prime
AC power and supporting equipment available.

2.5.1 Initial Power-Up

Before initial power up of the modem, it is a good idea to disconnect the
transmit output from the operating ground station equipment. This is
especially true if the current Modulator Configuration Settings are
unknown, where incorrect settings could disrupt the existing
communications traffic. New units from the factory are normally shipped
in a default configuration which includes setting the transmit carrier off.

Turn on the unit by placing the Rear Panel Switch (located above the power entry connector) to
the On Position. Upon initial and subsequent power-ups, the Microprocessor will test itself and
several of its components before beginning its Main Monitor/Control Program. These power-up
diagnostics show no results if successful. If a failure is detected, the Fault LED will illuminate.

The initial field checkout of the modem can be accomplished from the Front Panel or in the
Terminal Mode. The Terminal Mode has the advantage of providing full screen access to all of
the modem’s parameters, but requires a separate terminal or computer running a Terminal
Program. The Terminal Mode is enabled from the front panel in the System M&C Submenus.

2.5.2 Factory Terminal Setup

The factory terminal setup is as follows:

Emulation Type: VT-100 (can be changed)

Baud Rate: 19.2 K (Can be changed via Front Panel)
Data Bits: 8
Parity: No Parity (Fixed)
Stop Bits: 1 Stop Bit

2.6 Storage

It is recommended that the unit be stored in its original sealed packing. The unit should be stored
in a dry location where the temperature is stable, away from direct contact with rain, snow, wind,
sun, or anything that may cause damage.

TM136 – Rev. 1.1 2-5

Installation DMDVR20 LBST Satellite Modem

2-6 TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Theory of Operation

Theory of Operation

3

3.0 Modem Hardware

The modem is based on a two printed circuit card (minimum configuration) design with additional
optioned printed circuit cards available for additional features. The minimum configuration
consists of a Digital Baseband assembly, Tx L-Band assembly and RX L-Band Receiver
assembly. The optional printed circuit cards include a Turbo Codec printed circuit card an
optional data interface printed circuit card (refer to Appendix A). A block diagram of the Modem is
shown in Figure 3.1.

Rx L-Band

LDPC

IF Card

Cable Cable

Tx L-Band

IF Card

Interface

Card

(Optional)

Digital Baseband

Card

Cables

Tx Turbo

Card

(Optional)

Figure 3-1. Block Diagram

3.0.1 L-Band Printed Circuit Card

The L-Band circuit cards consists of an analog modulation function, an analog complex down
conversion, and two wide-band digital synthesizers. The block diagram of the L-Band assembly
is shown in Figure 3-2.

In the modulator, analog in-phase (I) and quadrature (Q) signals are generated on the Digital
Baseband Printed Circuit Card, routed to the L-Band Printed Circuit Card, and modulated at the
desired frequency. The L-Band modulated signal is then passed through a microprocessor
controlled variable attenuator providing gain control of the output signal.

TM136 – Rev. 1.1 3-1

Theory of Operation DMDVR20 LBST Satellite Modem

In the complex downconverter, the signal for demodulation is amplified and sent through a
variable wideband attenuator for AGC. The gain-controlled signal is then passed through a
complex downconverter to a low IF.

Figure 3-2. IF Card Block Diagram

3.0.2 Baseband Processing Printed Circuit Card

The advent of million-plus gate count FPGAs, advanced logic synthesis tools, and DSPs
providing hundreds of MIPs enabled the design of a software configurable modem. Large, fast
FPGAs now provide designers with what is essentially an on the fly programmable ASIC. High
speed, complex digital logic functions that previously could only be implemented in dedicated
integrated circuits are now downloaded from a micro-controller through a serial or peripheral
interface. When a new digital logic function is needed, a new configuration file is loaded into the
FPGA. There is no limit to the number of digital logic configurations available to the FPGA, aside
from the amount of Flash memory available to the system microprocessor for storage of
configuration files.

The Baseband Processing Printed Circuit Card provides a flexible architecture that allows
different modes of terrestrial and satellite framing, various FEC options, and several different
modulation/demodulation formats. Also included on the Baseband Printed Circuit Card are three
synchronous interfaces, an EIA-530 Interface supporting RS-422, V.35, and RS-232. All three
interfaces are provided on the same DB-25 Connector, and are selectable from the front panel.

3-2 TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Theory of Operation

The Baseband Printed Circuit Card also contains the Monitor and Control (M&C) Circuitry
responsible for:

 Programmable part setup and initialization
 Continuous control and adjustment of some functions
 Calibration
 Monitoring fault status
 Calculating and displaying measurements
 User monitor and control interface including front panel and remote
 Units configuration and feature set

The M&C System is based on a powerful microprocessor with a large amount of Flash memory.
Several bus architectures are used to interconnect the M&C to all components of the modem.
Communication to the outside world is done via connections to the remote port, terminal port,
Ethernet port, and alarm ports. The M&C runs off of software programmed into its Flash memory.
The memory can be reprogrammed via the Ethernet port to facilitate changes in software.

3.0.3 Enhanced Interface Printed Circuit Card

The normal terrestrial data for the Baseband Processing Card can be re-routed to the enhanced
interface card. The enhanced interface card adds a variety of connections to the modem for
additional applications

3.1 Functional Block Diagram

Figure 3-3 represents the Functional Blocks. The modem is shown in a typical application with
customer data, Tx/Rx RF equipment and an antenna.

TM136 – Rev. 1.1 3-3

Theory of Operation DMDVR20 LBST Satellite Modem

Aux.

Interface(s)

Sync Data

I/O

Alarms

Form-C

Contacts

Fault

Form-C

Contacts

Open

Collector

Faults

Front

Panel

Terrestrial

Interface

10 Base-T

Ethernet

Satellite

Modem

Digital
Baseband
Processor

Tx DSP

Rx DSP

M&C

Terminal

Modem

MOD

FPGA

DEMOD

FPGA

Remote

Port

Power

Supply

1 x 10
Ref. 40

MHz Clk

LDPC
RCVR

-7

IF Output

950-2050 MHz

0 to -25 dBm

Tx

RF

Equipment

Antenna

IF Input

950-2150 MHz

Rx
RF

Equipment

100 – 240 VAC

50 – 60 Hz

-48 VDC
(Option)

LAN Remote Serial Interfaces

Figure 3-3. Satellite Modem Functional Block Diagram

3.1.1 Front Panel

The Front Panel includes a 2 x 16 backlit LCD Display, Indicator LEDs, and a Numeric Keypad
(refer to Section 4.1).

3.1.2 Baseband Processing

The Baseband Processor performs all Modulator functions required for an IBS Framing Unit, and
Reed-Solomon Codec. In addition, the Baseband Processing Section provides for transmit clock
selection and rate adaptation as well as a rate adapter and Plesiochronous/Doppler (PD) Buffer in
the receive direction. A multiplexer is also provided for the SCT Clock Source for Loop Timing
Applications. The transmit and receive paths are configured independently under processor
control.

3-4 TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Theory of Operation

3.1.3 Tx Baseband Processing

The Tx Data and Clock enters the Baseband Processor, passes through a Rate Adapting FIFO
and enters the Framer/Drop Processor. In IBS mode, the framer adds the appropriate framing as
defined in 309. The data is then sent to the Reed-Solomon Encoder.

When enabled, the Reed-Solomon Encoder, encodes the data into Reed-Solomon Blocks. The
blocks are then interleaved and synchronized to the frame pattern as defined by the selected
specification (IESS-309, etc.). After Reed-Solomon Encoding, the composite data and clock are
applied to the BB Loopback Circuit.

3.1.4 Rx Baseband Processing

The Receive Processor performs the inverse function of the Tx Processor. Data received from
the satellite passes through the LDPC Receiver to the Decoder/Deframer. The Deframer
acquires the LDPC frame, and extracts the received data, placing the data into the PD Buffer,
sending the overhead data to the UIM. The data is extracted from the buffer and is sent to the
UIM.

3.2 Monitor & Control (M&C) Subsystem

The modems M&C system is connected to most of the circuitry on any board contained in the
modem. These connections provide status on the working condition of the circuitry as well as
providing the data required for the various measurements the modem provides. The M&C
processes this information and generates status indications as well as alarms when necessary.
Detailed status information is available via the modems various user interfaces including the
remote and terminal ports. An external summary fault is available on the RS422 Data interface

The M&C contains a high-performance microprocessor and is responsible for overall command
and control of modem functions. The M&C is constantly monitoring all subsystems of the modem
by performing a periodic poll routine and configures the modem by responding to commands
input to the system. During each poll cycle, the status of each of the subsystems is collected and
reported to each of the external ports. Performance statistics such as Eb/No, buffer fill %, etc.
are compiled. If faults are detected, the M&C will take appropriate actions to minimize the effect
of such faults on the system (refer to the Fault Matrices in Section 6).

The modem supports the following M&C protocols:

 Terminal Interface (Section 3.2.1)
 Remote Port Interface (Section 3.2.2)
 Modem Status, Alarms & Contact Closures (Section 3.2.4)

TM136 – Rev. 1.1 3-5

Theory of Operation DMDVR20 LBST Satellite Modem

3.2.1 Terminal Port (Supported in Rev B or greater)

This port supports an asynchronous control protocol as described in Section 4. It is configured to
support RS-232 signal levels. This port is intended for use in computer-based remote M&C. All
functions of the modem may be monitored and controlled from this port via a common terminal
connected to the Terminal Port. This function is front panel selectable.

The Terminal Mode Control allows the use of an external terminal or computer to monitor and
control the modem from a full screen interactive presentation operated by the modem itself. No
external software is required other than VT-100 Terminal Emulation Software (e.g. “Procomm”
for a computer when used as a terminal. The Control Port is normally used as an RS–232
Connection to the terminal device. The RS-232 operating parameters can be set using the
modem Front Panel and stored in Non-volatile memory for future use.

Refer to the Remote Protocol Manual (TM137) for the Terminal and

Remote screens and protocols.

3.2.2 Modem Remote Communications (RLLP)

The Remote Port located on J20 allows for control and monitoring of parameters and functions
via an RS-232 Serial Interface, or RS-485 for RLLP Protocol. ‘Equipment Remote Mode’ setup
can be entered from the front panel under the “System” menu. This requires the user to first set
the Remote Port Control to “Remote” then set the Multidrop Address as needed followed by
setting the Remote Interface to RS232 or RS485.

Control and status messages are conveyed between the modem and all subsidiary modems and
the host computer using packetized message blocks in accordance with a proprietary
communications specification. This communication is handled by the Radyne Link Level Protocol
(RLLP), which serves as a protocol ‘wrapper’ for the RM&C data. Complete information on
monitor and control software is contained in the following sections.

3.2.3 Ethernet M&C Port (Not Supported)

3.2.4 Modem Monitor Status

The modems M&C system is connected to most of the circuitry on any board contained in the
chassis. These connections provide status on the working condition of the circuitry as well as
providing the data required for the various measurements the modem provides. The M&C
processes this information and generates status indications as well as alarms when necessary.
Detailed status information is available via the modems various user interfaces (front panel,
remote and terminal). A summary of this information can be connected to external equipment,
switches or alarms via the open collector and/or form-C fault connections

3-6 TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Theory of Operation

Form-C Contacts:

The UIM provides three Form-C Relays under processor control that appear at J15.

Mod Fault: De-energized when any transmit side fault is detected.

Demod Fault: De-energized when any receive side fault is detected.

Common Fault: De-energized when any fault that is not explicitly a Tx or

Rx Fault such as an M&C or Power Supply Fault.

Open Collector Faults:

The UIM provides two Open Collector Faults that appear at Pins 18 & 21 on J19.

Mod Fault: Will sink up to 20 ma (maximum) until a transmit or

common fault is detected. Will not sink current if a fault
is detected.

Demod Fault: Will sink up to 20 ma (maximum) until a receive or

common fault is detected. Will not sink current if a fault
is detected.

The open collector faults are intended for use in redundancy switch applications in order to
provide quick status indications.

3.3 Internal Clock

The time and date is kept in order to ‘time-tag’ system events. User can change the Internal
Clock via the front panel or Terminal ports.

TM136 – Rev. 1.1 3-7

Theory of Operation DMDVR20 LBST Satellite Modem

3.4 Loopback Features (Terrestrial)

The modem provides for a number of different loopbacks. The Loopback supported are:

 TX Terrestrial Loopback - Tx Data port is looped back to the Rx Data port after the

interface driver/receiver. (prior to the framing unit)

 TX Baseband Loopback - Tx Data port is looped back to the Rx Data port after the

interface driver/receiver. (after the framing unit)

 RX Terrestrial Loopback - Receive Data from the satellite is looped back for

retransmission to the satellite, providing a far end loopback. (prior to the framing
unit)

 RX Baseband Loopback - Receive Data from the satellite is looped back for

retransmission to the satellite, providing a far end loopback. (after to framing unit)

Usage of the modems loopback capabilities in conjunction with the

Ethernet data interface can produce undesirable network loops. In order

to run any type of data test with an Ethernet interface you must utilize

two modems connected back to back. Simply using one modem and a

loopback will not produce the desired results.

3-8 TM136 – Rev. 1.1

DMDVR20 LBST Satellite Modem Theory of Operation

Figure 3-5. Loopback Functional Block Diagram

TM136 – Rev. 1.1 3-9