Comtech EF Data SDM-100A User Manual
SDM-100A
Satellite Modem
Installation and Operation Manual
Part Number MN/SDM100A.IOM
Revision 0
EFData Corporation is an ISO 9001 Registered Company
SDM-100A
Satellite Modem
Installation and Operation Manual
Part Number MN/SDM100A.IOM
Revision 0
November 27, 1996
Special Instructions:
This is the first edition of the manual.
Copyright © EFData Corporation, 1996.
All rights reserved.
Printed in the USA.
EFData Corporation, 2105 West 5th Place, Tempe, Arizona 85281 USA, (602) 968-0447, FAX: (602) 921-9012.
Warranty Policy
This EFData Corporation product is warranted against defects in material and
workmanship for a period of one year from the date of shipment. During the warranty
period, EFData will, at its option, repair or replace products that prove to be defective.
For equipment under warranty, the customer is responsible for freight to EFData and
all related custom, taxes, tariffs, insurance, etc. EFData is responsible for the freight
charges only for return of the equipment from the factory to the customer. EFData will
return the equipment by the same method (i.e., Air, Express, Surface) as the
equipment was sent to EFData.
Limitations of Warranty
The foregoing warranty shall not apply to defects resulting from improper installation or
maintenance, abuse, unauthorized modification, or operation outside of environmental
specifications for the product, or, for damages that occur due to improper repackaging
of equipment for return to EFData.
No other warranty is expressed or implied. EFData Corporation specifically
disclaims the implied warranties of merchantability and fitness for particular
purpose.
Exclusive Remedies
The remedies provided herein are the buyer's sole and exclusive remedies. EFData
Corporation shall not be liable for any direct, indirect, special, incidental, or
consequential damages, whether based on contact, tort, or any other legal theory.
Disclaimer
EFData has reviewed this manual thoroughly in order that it will be an easy-to-use
guide to your equipment. All statements, technical information, and recommendations
in this manual 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. Further, EFData reserves the right to make
changes in the specifications of the products described in this manual at any time
without notice and without obligation to notify any person of such changes.
If you have any questions regarding your equipment or the information in this manual,
please contact the EFData Customer Support Department. (For more information,
refer to the preface.)
About this Manual
This manual provides installation and operation information for the EFData SDM-100A
satellite modem. This is a technical document intended for earth station engineers,
technicians, and operators responsible for the operation and maintenance of the
SDM-100A.
Preface
Conventions and References Used in this Manual
Cautions and Warnings
CAUTION indicates a hazardous situation that, if not avoided, may result in
minor or moderate injury. CAUTION may also be used to indicate other
CAUTION
WARN ING
unsafe practices or risks of property damage.
WARNING indicates a potentially hazardous situation that, if not avoided,
could result in death or serious injury.
Rev. 0 i
Preface SDM-100A Satellite Modem
Military Standards
References to “MIL-STD-188” apply to the 114A series (i.e., MIL-STD-188-114A),
which provides electrical and functional characteristics of the unbalanced and balanced
voltage digital interface circuits applicable to both long haul and tactical
communications. Specifically, these references apply to the MIL-STD-188-114A
electrical characteristics for a balanced voltage digital interface circuit, Type 1 generator,
for the full range of data rates. For more information, refer to the Department of Defense
(DOD) MIL-STD-188-114A, “Electrical Characteristics of Digital Interface Circuits.”
Trademarks
Product names mentioned in this manual may be trademarks or registered trademarks of
their respective companies and are hereby acknowledged.
Related Documents
The following documents are referenced in this manual:
• Department of Defense (DOD) MIL-STD-188-114A, “Electrical Characteristics
of Digital Interface Circuits”
• EIA-STD-RS-422/449
• EIA-STD-RS-232-C
• CCITT Recommendation V.35
• INTELSAT Document IESS-308
• INTELSAT Document IESS-309
• EFData Specification SP/2515
ii Rev. 0
SDM-100A Satellite Modem Preface
European EMC Directive
In order to meet the European Electro-Magnetic Compatibility (EMC) Directive
(EN55022, EN50082-1), properly shielded cables for DATA I/O are required. More
specifically, these cables must be double-shielded from end-to-end, ensuring a continuous
ground shield.
The following information is applicable for the European Low Voltage Directive
(EN60950):
<HAR> Type of power cord required for use in the European Community.
CAUTION: Double-pole/Neutral Fusing
!
International Symbols:
ACHTUNG: Zweipolige bzw. Neutralleiter-Sicherung
Alternating Current.
Fuse.
Safety Ground.
Chassis Ground.
Note: For additional symbols, refer to “Cautions and Warnings” listed earlier in this
preface.
Reporting Comments or Suggestions Concerning this Manual
Comments and suggestions regarding the content and design of this manual will be
appreciated. To submit comments, please contact the EFData Customer Support
Department according to the following information.
Rev. 0 iii
Preface SDM-100A Satellite Modem
Customer Support
Contact the EFData Customer Support Department for:
• Product support
• Information on returning a product
• Information on upgrading a product
• Product training
• Reporting comments or suggestions concerning manuals
An EFData Customer Support representative may be reached at:
EFData Corporation
Attention: Customer Support Department
2105 West 5th Place
Tempe, Arizona 85281 USA
(602) 968-0447 (Main EFData Number)
(602) 517-2444 (Customer Support Desk)
(602) 921-9012 FAX
or, E-Mail can be sent to the Customer Support Department at:
service@efdata.com
To return an EFData product (in-warranty and out-of-warranty) for repair or replacement:
1. Request a Return Material Authorization (RMA) number from the EFData
Customer Support Department.
Be prepared to supply the Customer Support representative with the model
number, serial number, and a description of the problem.
2. To ensure that the product is not damaged during shipping, pack the product in
its original shipping carton/packaging.
3. Ship the product back to EFData. (Shipping charges should be prepaid.)
For more information regarding the warranty policies, refer to the disclaimer page
located behind the title page.
iv Rev. 0
Table of Contents
CHAPTER 1. INTRODUCTION.................................................................................. 1–1
1.1 Purpose and Function ..................................................................................................................................1–2
1.2 Description....................................................................................................................................................1–3
1.3 Options ..........................................................................................................................................................1–4
1.3.1 ASYNC/AUPC Interface........................................................................................................................1–4
1.3.2 ADPCM Voice........................................................................................................................................1–4
1.4 Modem Specifications ..................................................................................................................................1–5
1.5 BER Performance ........................................................................................................................................1–7
CHAPTER 2. INSTALLATION................................................................................... 2–1
2.1 Unpacking .....................................................................................................................................................2–1
2.2 System Installation.......................................................................................................................................2–2
2.3 System Requirements...................................................................................................................................2–3
2.4 External Connections................................................................................................................................... 2–5
2.4.1 DATA I/O Interface (J8) ........................................................................................................................2–6
2.4.2 Remote (J6).............................................................................................................................................2–6
2.4.3 Faults (J7) ...............................................................................................................................................2–7
2.4.4 TX IF Output (CP1)................................................................................................................................ 2–7
2.4.5 RX IF Input (CP2) .................................................................................................................................. 2–8
2.4.6 AC Power ...............................................................................................................................................2–8
2.4.7 DC Power ...............................................................................................................................................2–8
2.4.8 GND........................................................................................................................................................2–8
2.4.9 AGC Test Point.......................................................................................................................................2–8
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Table of Contents SDM-100A Satellite Modem
CHAPTER 3. OPERATION........................................................................................ 3–1
3.1 Front Panel ...................................................................................................................................................3–1
3.1.1 Front Panel Keypad Option ....................................................................................................................3–2
3.1.2 LED Indicators........................................................................................................................................3–2
3.1.3 Front Panel Controls ...............................................................................................................................3–3
3.2 Menu System ................................................................................................................................................3–4
3.2.1 Standard SDM-100 Menus ..................................................................................................................... 3–5
3.2.1.1 Configuration ..................................................................................................................................3–7
3.2.1.1.1 Configuration Modulator .........................................................................................................3–9
3.2.1.1.2 Configuration Demodulator ...................................................................................................3–13
3.2.1.1.3 Configuration Interface ..........................................................................................................3–18
3.2.1.1.4 Configuration Local AUPC ...................................................................................................3–23
3.2.1.2 Monitor..........................................................................................................................................3–25
3.2.1.3 Faults/Alarms ................................................................................................................................3–26
3.2.1.3.1 Modulator Faults....................................................................................................................3–29
3.2.1.3.2 Demodulator Faults................................................................................................................ 3–30
3.2.1.3.3 TX Interface Faults ................................................................................................................3–31
3.2.1.3.4 RX Interface Faults ................................................................................................................3–31
3.2.1.3.5 Common Equipment Faults....................................................................................................3–32
3.2.1.4 Stored Faults/Alarms.....................................................................................................................3–35
3.2.1.5 Remote AUPC...............................................................................................................................3–36
3.2.1.6 Utility.............................................................................................................................................3–37
3.2.1.6.1 Utility Modulator ...................................................................................................................3–39
3.2.1.6.2 Utility Demodulator ...............................................................................................................3–43
3.2.1.6.3 Utility Interface ......................................................................................................................3–45
3.2.1.6.4 Utility System.........................................................................................................................3–49
3.2.1.6.5 Utility Modem Type...............................................................................................................3–51
3.2.1.6.6 Utility Factory Set-Up............................................................................................................ 3–52
3.2.2 Type 1 Operation Menus ......................................................................................................................3–53
3.2.2.1 Configuration: Type 1 Operation ..................................................................................................3–55
3.2.2.2 Monitor: Type 1 Operation............................................................................................................3–60
3.2.2.3 Faults/Alarms: Type 1 Operation ..................................................................................................3–61
3.2.2.3.1 Modulator Faults: Type 1 Operation...................................................................................... 3–63
3.2.2.3.2 Demodulator Faults: Type 1 Operation..................................................................................3–63
3.2.2.3.3 Common Equipment Faults: Type 1 Operation .....................................................................3–63
3.2.2.4 Stored Faults/Alarms: Type 1 Operation....................................................................................... 3–65
3.2.2.5 Utility Functions............................................................................................................................ 3–66
3.2.2.5.1 Utility Modulator: Type 1 Operation ..................................................................................... 3–69
3.2.2.5.2 Utility Demodulator Functions: Type 1 Operation ................................................................ 3–71
3.2.2.5.3 Utility Interface Functions: Type 1 Operation .......................................................................3–73
3.2.2.5.4 Utility System Functions: Type 1 Operation..........................................................................3–75
3.3 Clocking Options........................................................................................................................................3–79
3.3.1 Master/Master .......................................................................................................................................3–79
3.3.2 Master/Slave .........................................................................................................................................3–79
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SDM-100A Satellite Modem Table of Contents
CHAPTER 4. THEORY OF OPERATION.................................................................. 4–1
4.1 Modulator ..................................................................................................................................................... 4–1
4.1.1 Theory of Operation ...............................................................................................................................4–1
4.1.2 Specifications..........................................................................................................................................4–5
4.2 Demodulator .................................................................................................................................................4–6
4.2.1 Theory of Operation ...............................................................................................................................4–6
4.2.2 Specifications..........................................................................................................................................4–6
4.2.3 Viterbi Decoding Theory........................................................................................................................4–7
4.2.4 Sequential Decoding Theory ..................................................................................................................4–9
4.3 Monitor and Control.................................................................................................................................. 4–11
4.3.1 Non-Volatile Memory...........................................................................................................................4–11
4.3.2 M&C Theory of Operation ................................................................................................................... 4–11
4.3.3 Remote Interface Specification............................................................................................................. 4–11
4.3.4 Remote Interface Configuration ...........................................................................................................4–12
4.3.5 Modem Defaults ...................................................................................................................................4–13
4.4 Digital Interfaces ........................................................................................................................................4–14
4.4.1 RS-422 Interface...................................................................................................................................4–14
4.4.1.1 Connector Pinouts .........................................................................................................................4–17
4.4.1.2 Specification..................................................................................................................................4–18
4.4.2 V.35 Interface ....................................................................................................................................... 4–18
4.4.2.1 Connector Pinouts .........................................................................................................................4–21
4.4.2.2 Specification..................................................................................................................................4–22
4.4.3 RS-232-C Interface...............................................................................................................................4–22
4.4.3.1 Theory of Operation ......................................................................................................................4–23
4.4.3.2 Connector Pinouts .........................................................................................................................4–25
4.4.4 Asynchronous Interface ........................................................................................................................4–26
4.4.5 Terrestrial Interface Change .................................................................................................................4–26
CHAPTER 5. MAINTENANCE................................................................................... 5–1
5.1 System Checkout ..........................................................................................................................................5–1
5.1.1 Interface Checkout..................................................................................................................................5–1
5.1.2 Modulator Checkout ...............................................................................................................................5–2
5.1.3 Demodulator Checkout...........................................................................................................................5–2
5.1.4 Test Points ..............................................................................................................................................5–6
5.1.4.1 Demodulator/M&C/Interface Test Points .......................................................................................5–6
5.1.4.2 Modulator Test Points .....................................................................................................................5–7
5.2 Fault Isolation...............................................................................................................................................5–8
5.3 Module Identification...................................................................................................................................5–9
APPENDIX A. REMOTE CONTROL OPERATION ...................................................A–1
A.1 General ........................................................................................................................................................A–1
A.2 Message Structure......................................................................................................................................A–2
A.2.1 Start Character ......................................................................................................................................A–2
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Table of Contents SDM-100A Satellite Modem
A.2.2 Device Address .....................................................................................................................................A–2
A.2.3 Command/Response .............................................................................................................................A–3
A.2.4 End Character .......................................................................................................................................A–3
A.3 Configuration Commands/Responses.......................................................................................................A–4
A.3.1 Modulator..............................................................................................................................................A–4
A.3.2 Demodulator .........................................................................................................................................A–6
A.3.3 Interface ................................................................................................................................................ A–8
A.3.4 System................................................................................................................................................. A–12
A.3.5 AUPC.................................................................................................................................................. A–12
A.4 Status Commands/Responses .................................................................................................................. A–14
A.4.1 Configuration ......................................................................................................................................A–14
A.4.2 Error Performance...............................................................................................................................A–27
A.5 Stored Faults.............................................................................................................................................A–28
APPENDIX B. OPTIONS ...........................................................................................B–1
B.1 AUPC Interface .......................................................................................................................................... B–1
B.1.1 Theory of Operation.............................................................................................................................. B–4
B.1.1.1 Terrestrial Data Interfaces ............................................................................................................. B–4
B.1.1.2 ASYNC Data Interfaces................................................................................................................. B–4
B.1.1.3 Multiplexer Operation.................................................................................................................... B–4
B.1.1.4 Demultiplexer Operation ...............................................................................................................B–5
B.1.1.5 Buffer Operation............................................................................................................................ B–5
B.1.1.6 Loop Timing Operation ................................................................................................................. B–6
B.1.1.7 Baseband Loopback Operation...................................................................................................... B–6
B.1.1.8 Non-ASYNC Operation................................................................................................................. B–6
B.1.1.9 ASYNC Channel RS-485 2- and 4-Wire....................................................................................... B–6
B.1.1.10 Valid ASYNC Baud Rates........................................................................................................... B–7
B.1.2 Installation Instructions......................................................................................................................... B–7
B.1.2.1 Top Cover Removal....................................................................................................................... B–8
B.1.2.2 Interface Mounting Bracket Removal............................................................................................ B–8
B.1.2.3 EPROM Installation....................................................................................................................... B–8
B.1.2.4 ASYNC Interface........................................................................................................................... B–8
B.1.2.5 Installing Top Cover ...................................................................................................................... B–8
B.1.3 Front Panel Operation ........................................................................................................................... B–9
B.1.3.1 Interface Configuration.................................................................................................................. B–9
B.1.3.2 Modulation Configuration ...........................................................................................................B–10
B.1.3.3 Demodulation .............................................................................................................................. B–10
B.1.3.4 Utility/Interface............................................................................................................................ B–10
B.1.3.5 Specifications............................................................................................................................... B–11
B.1.3.6 Mechanical Specifications for Connector J1 ...............................................................................B–11
B.2 ADPCM Voice Interface .......................................................................................................................... B–12
B.2.1 Theory of Operation............................................................................................................................ B–12
B.2.1.1 Multiplexer .................................................................................................................................. B–14
B.2.1.2 Demultiplexer .............................................................................................................................. B–14
B.2.1.3 Protection Switch.........................................................................................................................B–15
B.2.1.4 RS-422 Interface.......................................................................................................................... B–15
B.2.2 Front Panel Operation ......................................................................................................................... B–16
B.2.2.1 Interface ....................................................................................................................................... B–16
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SDM-100A Satellite Modem Table of Contents
B.2.2.2 Modulator Configuration ............................................................................................................. B–16
B.2.2.3 Demodulator Configuration......................................................................................................... B–16
B.2.2.4 Utility/Interface............................................................................................................................ B–17
B.2.2.5 TX Alarm Indication.................................................................................................................... B–17
B.2.2.6 RX Alarm Indication ................................................................................................................... B–17
B.2.2.7 DEMUX Lock ............................................................................................................................. B–17
B.2.2.8 Remote Off Hook ........................................................................................................................ B–17
B.2.3 Specifications ...................................................................................................................................... B–18
B.3 Reed-Solomon Codec................................................................................................................................ B–19
B.3.1 Reed-Solomon Encoder ......................................................................................................................B–19
B.3.2 Reed-Solomon Decoder ...................................................................................................................... B–22
GLOSSARY ............................................................................................................... g–1
Rev. 0 ix
Table of Contents SDM-100A Satellite Modem
Figures
Figure 1-1. SDM-100A....................................................................................................................................1–1
Figure 1-2. SDM-100A Block Diagram .......................................................................................................... 1–2
Figure 1-3. Dimensional Drawing ................................................................................................................... 1–4
Figure 1-4. Viterbi Bit Error Rate Performance ..............................................................................................1–8
Figure 1-5. Sequential Bit Error Rate Performance.........................................................................................1–9
Figure 1-6. Typical Output Spectrum ............................................................................................................1–10
Figure 2-1. Typical Rack Elevation.................................................................................................................2–4
Figure 2-2. Rear Panel View............................................................................................................................2–5
Figure 3-1. Front Panel View ..........................................................................................................................3–1
Figure 3-2. Main Menu (SDM-100 Operation) ............................................................................................... 3–5
Figure 3-3. Configuration Modulator (SDM-100 Operation).......................................................................... 3–8
Figure 3-4. Configuration Demodulator (SDM-100 Operation)....................................................................3–12
Figure 3-5. Configuration Interface (SDM-100 Operation) ..........................................................................3–16
Figure 3-5. Configuration Interface Continued (SDM-100 Operation).........................................................3–17
Figure 3-6. Configuration Local AUPC (SDM-100 Operation)....................................................................3–22
Figure 3-7. Monitor (SDM-100 Operation)...................................................................................................3–24
Figure 3-8. Faults/Alarms (SDM-100 Operation) .........................................................................................3–28
Figure 3-9. Stored FLTS/ALMS (SDM-100 Operation) ...............................................................................3–34
Figure 3-10. Remote AUPC (SDM-100 Operation)......................................................................................3–36
Figure 3-11. Utility Modulator (SDM-100 Operation).................................................................................. 3–38
Figure 3-12. Utility Demodulator ..................................................................................................................3–42
Figure 3-13. Utility Interface (SDM-100 Operation) ....................................................................................3–44
Figure 3-14. Utility System (SDM-100 Operation).......................................................................................3–48
Figure 3-15. Utility Modem Type (SDM-100 and Type 1 Operation) ..........................................................3–51
Figure 3-16. Utility Factory Setup (SDM-100 and Type 1 Operation) .........................................................3–52
Figure 3-17. Main Menu (Type 1 Operation) ................................................................................................3–53
Figure 3-18. Configuration (Type 1 Operation) ............................................................................................3–54
Figure 3-19. Monitor (Type 1 Operation)......................................................................................................3–60
Figure 3-20. Faults/Alarms (Type 1 Operation) ............................................................................................ 3–62
Figure 3-21. Stored FLT/ALMS (Type 1 Operation) ....................................................................................3–64
Figure 3-22. Utility Modulator (Type 1 Operation).......................................................................................3–68
Figure 3-23. Utility Demodulator (Type 1 Operation) ..................................................................................3–70
Figure 3-24. Utility Interface (Type 1 Operation) .........................................................................................3–72
Figure 3-25. Utility System (Type 1 Operation)............................................................................................3–74
Figure 3-26. RF Loopback............................................................................................................................. 3–77
Figure 3-27. IF Loopback ..............................................................................................................................3–78
Figure 3-28. Baseband Loopback ..................................................................................................................3–78
Figure 3-29. Master/Master Clocking Block Diagram ..................................................................................3–80
Figure 3-30. Master/Slave Clocking Block Diagram.....................................................................................3–81
Figure 4-1. Modulator Block Diagram ............................................................................................................ 4–2
Figure 4-2. BPSK Ordering, Viterbi ...............................................................................................................4–4
Figure 4-3. Demodulator Block Diagram ........................................................................................................4–7
Figure 4-4. Viterbi Decoder Block Diagram ...................................................................................................4–8
Figure 4-5. Sequential Decoder Block Diagram............................................................................................ 4–10
Figure 4-6. RS-422 Block Diagram...............................................................................................................4–15
Figure 4-7. V.35 Interface .............................................................................................................................4–19
Figure 4-8. RS-232-C Interface ..................................................................................................................... 4–23
Figure 5-1. Typical Output Spectrum ..............................................................................................................5–3
Figure 5-2. Typical Output Spectrum With Noise........................................................................................... 5–3
Figure 5-3. Typical Eye Constellations ...........................................................................................................5–5
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SDM-100A Satellite Modem Table of Contents
Figure 5-4. Fault Tree ......................................................................................................................................5–8
Figure B-1. ASYNC/AUPC Block Diagram .................................................................................................. B–2
Figure B-2. System Interface Diagram ......................................................................................................... B–12
Figure B-3. ADPCM Block Diagram ........................................................................................................... B–13
Figure B-4. Reed-Solomon Codec Block Diagram ......................................................................................B–19
Figure B-5. Reed-Solomon Encoder Section Block Diagram ......................................................................B–20
Figure B-6. Reed-Solomon Code Page Format ............................................................................................ B–21
Figure B-7. Reed-Solomon Decoder Section Block Diagram ...................................................................... B–22
Tables
Table 1-1. SDM-100A Specifications .............................................................................................................1–5
Table 1-2. BER Performance Specification.....................................................................................................1–7
Table 2-1. Rear Panel Connectors ...................................................................................................................2–5
Table 4-1. M&C Jumper Settings (AS/4973) ................................................................................................ 4–15
Table 5-1. EFData Conversion of (S+N)/N to S/N and Eb/N0 for Various Code Rates .................................5–4
Table 5-2. EFData Part Numbers for Various Modules ..................................................................................5–9
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xii Rev. 0
Chapter 1.
INTRODUCTION
This chapter provides the description, options, and specifications for the SDM-100A
satellite modem, referred to in this manual as “the modem” (Figure 1-1).
Figure 1-1. SDM-100A
Rev. 0 1–1
Introduction SDM-100A Satellite Modem
A
A
A
ATA
A
A
ATA
ALA
A
A
A
A
A
A
A
A
1.1 Purpose and Function
The modem is ideally suited for networks implemented with digitized voice compressors.
These types of circuits require the minimum processing delay provided by the modem’s
Viterbi decoder. A system block diagram is shown in Figure 1-2.
The modem is also employed in transportable applications, where small size and low
power consumption are important.
DPCM
RS-232,
RS-422,
V.35, or
SYNC
CUSTOMER
I/O
D
CLOCK
RMS
FORM C
CONT
CTS
REMOTE
SERI
L
INTERF
CE
SDM-100A
S
TEL LITE
EXT.
MODEM
J8
J8
J7
J6
INTERFACE
MONITOR &
CONTROL
DISPLAY&
KEYP
D
COMMAND
D
CLK
SCT
BUS
DAT
CLK
FRONT
REMOTE
ENCODER/
MODUL
M&C
M&C
DEMOD
DECODER
P
NEL
(OPT.)
TOR
POWER
SUPPLY
IF OUTPUT
CP1
50 to 180 MHz
-5 to -3 0 dBm
90 to 264 VAC,
47 to 63 Hz
IF IN PUT
CP2
50 to90 MHz
100 to 180 MHz
-30to-55dBm
NSMIT
TR
EQUIPMENT
RECEIVE RF
EQUIPMENT
RF
NTENN
Figure 1-2. SDM-100A Block Diagram
The modem provides total flexibility in selection of the following data rates:
19.2 to 128 kbit/s 1/2 rate
28.8 to 192 kbit/s 3/4 rate
33.6 to 224 kbit/s 7/8 rate QPSK
9.6 to 64 kbit/s 1/2 rate BPSK
These parameters, as well as selection of elastic buffer, scrambler, differential encoder,
power levels, and carrier frequencies, can be selected from the front panel, or by remote
control via a serial interface.
Since the modem is software defined, it can be programmed to be end-to-end compatible
with other manufacturer’s modems at similar rates.
1–2 Rev. 0
SDM-100A Satellite Modem Introduction
The modem interfaces with IF converter equipment operating in a 50 to 180 MHz band.
The data interface options consist of RS-449/422, V.35, RS-232-C, ASYNC, and
Adaptive Differential Pulse Code Modulation (ADPCM) voice. Changes in connectors
for the various interfaces are accomplished by small, field-changeable connector
modules.
Recent advances in Digital Signal Processing (DSP) have been incorporated into the
modem’s design. Examples of high density components employed in the modem are:
• Embedded microprocessor
• Viterbi Large Scale Integration (LSI) processors
• Direct Digital Synthesis (DDS)
• Field programmable gate arrays for logic processing
Utilization of these state-of-the-art components and surface mount technology provides
maximum modem processing power in a minimum amount of space.
1.2 Description
The modem is a complete, self-contained unit in a standard 1 Unit (1U) 19”
rack-mountable enclosure weighing approximately 10 lbs. A dimensional drawing of the
modem is shown in Figure 1-3.
All monitor and control functions and indicators for operation of the modem are located
on the front panel. The display Printed Circuit Board (PCB) is mounted on the front
panel.
The chassis also contains the power supply. A fan is located on the rear panel.
The modem consists of the following assemblies:
Assembly Drawing #
Chassis with Power Supply AS/5281-X
PCB, Demod/M&C AS/4973
PCB, Interface Daughter (RS-422) AS/2524 (See note below)
PCB, Interface Daughter (V.35) AS/2532 or AS/4326
PCB, Interface Daughter (RS232) AS/2533 (See note below)
PCB, Interface Daughter (ASYNC) AS/4089 (See note below)
PCB, Interface Daughter (ADPCM) AS/3916 (See note below)
PCB, Modulator AS/2522
ASIC, Sequential Decoder IC/EFD 8858 (optional)
PCB, Mod RF AS/3995-X
PCB, Demod RF AS/4401-X
PCB, Reed-Solomon (SDM-100) AS/3708-2
(See note below)
Where X = various options available on the modulator and demodulator boards.
Refer to Table 5-2 for more information on the options available for each board.
Note: Only one interface option is shipped per modem.
Rev. 0 1–3
Introduction SDM-100A Satellite Modem
Figure 1-3. Dimensional Drawing
1.3 Options
For more information on the following options, refer to Appendix B.
1.3.1 ASYNC/AUPC Interface
The ASYNC interface board provides the interface for terrestrial data and a single
ASYNC overhead channel, along with an AUPC feature.
1.3.2 ADPCM Voice
The ADPCM voice interface is capable of providing a single, duplex voice channel and
Ear and Mouth (E&M) signaling data transmission.
1–4 Rev. 0
SDM-100A Satellite Modem Introduction
1.4 Modem Specifications
Table 1-1 lists the operating specifications of the modem.
Table 1-1. SDM-100A Specifications
Modem Specifications
Operating Frequency Range 50 to 180 MHz, synthesized in 2.5 kHz steps.
Type of Modulation Quadrature Phase Shift Keying (QPSK), or
Bi-Phase Shift Keying (BPSK).
Operating Channel Spacing Less than 0.5 dB degradation operating with 2
adjacent-like channels, each 10 dB higher at 1.3
times the symbol rate, or a minimum of 1.2 times the
specified acquisition range.
Bit Error Rate See Table 1-2.
Phase Noise In accordance with IESS-308.
Digital Interface RS-422/449 on 37-pin D.
(Field Changeable Plug-in modules) MIL-STD-188 on 37-pin D.
(One interface per module.) V.35 on 25-pin DIN.
RS-232-C on 25-pin D.
Asynchronous.
ADPCM.
Digital Data Rate
BPSK, 1/2 Rate 9.6 to 64 kbit/s.
QPSK, 1/2 Rate 19.2 to 128 kbit/s.
QPSK, 3/4 Rate 28.8 to 192 kbit/s.
QPSK, 7/8 Rate 33.6 to 224 kbit/s.
Doppler Buffer Programmable from 64 to 65536 bits, or from 1 to
50 ms total depth.
Buffer Output Clock Transmit, Receive, Internal, or External.
Transmit and external clocks must be to data rate.
Forward Error Correction Convolutional Encoding with Soft Decision.
K=7 Viterbi Decoding, or Sequential.
Data Scrambling Selectable (International Telephone and Telegraph
Consultative Committee) CCITT V.35, or None.
Prime Power 90 to 264 VAC Auto Select, 47 to 63 Hz,
50W Max., Fused at 2A. (48 VDC optional.)
Size 1.75” H x 19.0” W x 20.0” D. Refer to Figure 1-3.
Operating Temperature
Storage Temperature
Humidity 0 to 95% noncondensing.
Diagnostic Features IF Loopback.
RF Loopback.
Baseband Loopback (Bi-directional, electrical).
Fault Monitoring.
Bit Error Rate Monitoring.
Remote Control via Serial Port.
°
0
to 50°C.
°
-20
to +70°C.
Rev. 0 1–5
Introduction SDM-100A Satellite Modem
Additional Modulator Specifications
Output Power -5 to -30 dBm, adjustable in 0.1 dB steps.
Output Spurious and Harmonics -55 dBc in 4 kHz BW in-band (50 to 180 MHz).
-55 dBc in 4 kHz BW out-of-band (0 to 500 MHz).
Output Impedance 75Ω standard, or 50Ω optional.
Output Return Loss 20 dB.
Output Frequency Stability ± 10 PPM.
Data Clock Source Internal or external.
External clock,
± 100 PPM and < 5% jitter.
Internal Data Clock Stability ± 10 PPM.
Additional Demodulator Specifications
Input Power (Desired Carrier) -30 to -55 dBm (composite).
+30 dB power within 2 MHz from desired carrier.
+40 dB power outside of 2 MHz from desired carrier.
-5 dBm maximum composite.
Input Impedance 75Ω standard, or 50Ω optional.
Input Return Loss 20 dB.
Carrier Acquisition Range ± 25 kHz minimum.
Clock Acquisition Range ± 100 PPM.
Acquisition Time < 1 second typical at 64 kbit/s.
Directed Sweep:
Sweep Range 0 to 70000 Hz.
Sweep Center -35000 to +35000 Hz.
Remote Control Specifications
Serial Interface RS-232-C or RS-485, Baud Rate 110 to 19,200 bit/s.
Protocol not necessarily compatible with SDM-650B or
SDM-308B.
Signals Controlled/Monitored Transmit Frequency.
Receive Frequency.
Transmit Power.
Transmitter On/Off.
Data Rate Select.
IF Loopback.
RF Loopback.
Baseband Loopback.
Scrambler On/Off.
Descrambler On/Off.
Sweep Range.
Sweep Center.
Filter Mask.
Raw Error Rate.
Corrected Bit Error Rate.
Receive Eb/N0.
TX Clock Internal/External.
RX Clock Normal/Invert.
Receive Signal Level.
Receive Carrier Detect.
Power Supply Voltages.
Fault Status.
Stored Fault Status.
Configuration Retention Will maintain current configuration for up to one year
minimum without power.
Addressing Programmable to 1 of 255 possibilities.
Address 0 reserved for global addressing.
Local control of all remote functions included via push-button entry.
1–6 Rev. 0
SDM-100A Satellite Modem Introduction
1.5 BER Performance
The bit energy-to-noise ratio (Eb/N0) required to achieve 10-5 to 10-7 bit error rates is listed
in Table 1-2.
Table 1-2. BER Performance Specification
Viterbi K = 7
BER 1/2 Rate 3/4 Rate 7/8 Rate
10-5 5.5 dB 6.8 dB 8.1 dB
10-7 6.7 dB 8.3 dB 9.4 dB
The Bit Error Rate (BER) performance of the modem with a Viterbi decoder is shown in
Figure 1-4.
The BER performance of the modem with a sequential decoder is shown in Figure 1-5.
A typical output spectrum of the modem is shown in Figure 1-6.
Notes:
1. The modem alone, without coding, provides operation within 0.5 dB of
theoretical for BPSK, and within 0.8 dB for QPSK, for BERs in the range 10
-6
.
10
2. Performance measurements are made with Transmit and Receive IF connected
back-to-back through an additive white Gaussian noise channel.
3. The BER performance is in accordance with IESS-308 specifications.
-1
to
Rev. 0 1–7
Introduction SDM-100A Satellite Modem
-2
10
-3
10
-4
10
-5
10
-6
10
BER
-7
10
-8
10
-9
10
-10
10
3.0 4.0 5.0 6.0
Figure 1-4. Viterbi Bit Error Rate Performance
7/8 RATE3/4 RATE1/2 RATE
7.0 8.0 9.0 10.0 11.0
(dB)
E
b/N0
1–8 Rev. 0
SDM-100A Satellite Modem Introduction
-2
10
-3
10
-4
10
-5
10
-6
10
BER
-7
10
-8
10
-9
10
-10
10
3.0 4.0 5.0 6.0
Figure 1-5. Sequential Bit Error Rate Performance
3/4 RATE1/2 RATE 7/8 RATE
7.0 8.0 9.0 10.0 11.0
(dB)
E
b/N0
Rev. 0 1–9
Introduction SDM-100A Satellite Modem
/
/
K
RL -10.00 dBm
*ATTEN 0 dB
10.00 dB
DIV
SDM 100
TYPICAL SDM-100A
OUTPUT SPECTRUM
CENTER 70.000 0 MHz
Figure 1-6. Typical Output Spectrum
64 kbit
QPS
s, 1/2RATE
VITERBI
SPAN 500.0 kHz
1–10 Rev. 0
This chapter provides unpacking instructions, system requirements, and external
connections for the modem.
2.1 Unpacking
The modem and manual are packaged in pre-formed, reusable cardboard cartons that
contain foam spacing for maximum shipping protection. The circuit cards are contained
in the modem chassis.
To remove the modem:
CAUTION
Chapter 2.
INSTALLATION
Do not use any cutting tool that will extend more than 1” into the container
and cause damage to the modem.
1. Cut the tape at the top of the carton where it is indicated “OPEN THIS END.”
2. Lift out the cardboard/foam spacer covering the modem.
3. Remove the modem, manual, and power cord from carton.
4. Save the packing material for reshipment back to the factory or to another site.
5. Inspect the equipment for damage incurred during shipment.
Rev. 0 2–1
Installation SDM-100A Satellite Modem
6. Check the equipment against the packing list shipped with the equipment to
ensure that the shipment is complete.
7. Refer to Section 2.2 for further system installation instructions.
2.2 System Installation
Install the modem as follows:
1. Mount the modem chassis in the assigned position in the equipment rack. Refer
to Figure 2-1 for an illustration of a typical rack elevation for an M:N system.
2. Connect the cables to the appropriate locations on the rear panel. Refer to
Section 2.4 for connector pinouts, placement, and functions.
3. Before applying power, read and become familiar with Chapter 3.
Verify all jumper settings are correctly set for remote operation. Refer to
Chapter 4 for jumper settings.
4. Turn on the power switch (located on the rear panel).
5. Check for proper TX output signal level and spectrum.
6. Check for proper RX input signal level and spectrum.
7. If there are any problems with the installation, refer to Chapter 5 for
troubleshooting the system.
2–2 Rev. 0
SDM-100A Satellite Modem Installation
2.3 System Requirements
The standard modem with all the cards installed is a full-duplex QPSK satellite modem.
The system can also be configured for TX-only or RX-only.
• For a TX-only system, enter the UTILITY SYSTEM menu under FUNCTION
SELECT UTILITY on the front panel. Select OPERATION MODE.
Enter the menu and select Transmit Only. This will mask all receive faults and
receive stored faults in the Faults menu.
• For an RX-only system, enter the UTILITY SYSTEM menu under FUNCTION
SELECT UTILITY on the front panel. Select OPERATION MODE.
Enter the menu and select Receive Only. This will mask the transmit faults and
transmit stored faults in the Faults menu.
Rev. 0 2–3
Installation SDM-100A Satellite Modem
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
$
Figure 2-1. Typical Rack Elevation
2–4 Rev. 0
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