Comtech EF Data SNM-1001 User Manual
p
MULTIMEDIA INTEGRATED DIGITAL ACCESS SYSTEM
SNM-1001
Network Control Modem
O
eration and Maintenance Manual
Part Number MN/SNM1001.OM Revision 1
Comtech EFData is an ISO 9001
Registered Company.
SNM-1001
Network Control Modem
Operation and Maintenance Manual
Part Number MN/SNM1001.OM
Revision 1
May 31, 1999
Comtech EFData, 2114 West 7th Street, Tempe, Arizona 85281 USA, (480) 333-2200, FAX: (480) 333-2161.
Copyright © Comtech EFData, 2000. All rights reserved. Printed in the USA.
Customer Support
Contact the Comtech EFData Customer Support Department for:
• Product support or training
• Information on upgrading or returning a product
• Reporting comments or suggestions concerning manuals
A Customer Support representative may be reached at:
Comtech EFData
Attention: Customer Support Department
2114 West 7th Street
Tempe, Arizona 85281 USA
(480) 333-2200 (Main Comtech EFData Number)
(480) 333-4357 (Customer Support Desk)
(480) 333-2161 FAX
or, E-Mail can be sent to the Customer Support Department at:
service@comtechefdata.com
Contact us via the web at www.comtechefdata.com.
1. To return a Comtech EFData product (in-warranty and out-of-warranty) for
repair or replacement:
2. Request a Return Material Authorization (RMA) number from the Comtech
EFData Customer Support Department.
3. Be prepared to supply the Customer Support representative with the model
number, serial number, and a description of the problem.
4. To ensure that the product is not damaged during shipping, pack the product in
its original shipping carton /p ack ag ing .
5. Ship the product back to Comtech EFData. (Shipping charges should be prepaid.)
For more information regarding the warranty policies, see Warranty Policy, p. ix.
ii Rev. 1
Table of Contents
CHAPTER 1. INTRODUCTION........................................................................................1–1
1.1 Overview........................................................................................................................................................... 1–1
1.2 Mode of Operation........................................................................................................................................... 1–2
1.2.1 Description................................................................................................................................................ 1–4
1.3 Options .............................................................................................................................................................. 1–4
1.4 Specifications.................................................................................................................................................... 1–5
CHAPTER 2. INSTALLATION.........................................................................................2–1
2.1 Unpacking......................................................................................................................................................... 2–1
2.2 System Installation........................................................................................................................................... 2–2
2.3 External Modem Connectors.......................................................................................................................... 2–4
2.3.1 DATA I/O Interface (J8)........................................................................................................................... 2–4
2.3.1.1 EIA-422/449 Interface Connector Pinouts........................................................................................2–5
2.3.2 Remote (J6)............................................................................................................................................... 2–6
2.3.3 Faults (J7).................................................................................................................................................. 2–7
2.3.4 TX IF Output (CP1).................................................................................................................................. 2–7
2.3.5 RX IF Input (CP2)..................................................................................................................................... 2–8
2.3.6 AC Power.................................................................................................................................................. 2–8
2.3.7 DC Power.................................................................................................................................................. 2–8
2.3.8 Chassis GND............................................................................................................... .............................. 2–8
2.3.9 AGC Test Point......................................................................................................................................... 2–8
Rev. 1 iii
Preface SNM-1001 Network Control Modem
CHAPTER 3. OPERATION..............................................................................................3–1
3.1 Front Panel....................................................................................................................................................... 3–1
3.1.1 LED Indicator............................................................................................................................................ 3–2
3.1.2 Front Panel Keypad Option....................................................................................................................... 3–2
3.2 Clocking Options.............................................................................................................................................. 3–2
CHAPTER 4. THEORY OF OPERATION........................................................................4–1
4.1 Modulator......................................................................................................................................................... 4–1
4.1.1 Specifications............................................................................................................................................ 4–3
4.1.2 Theory of Operation .................................................................................................................................. 4–3
4.2 Demodulator..................................................................................................................................................... 4–5
4.2.1 Specifications............................................................................................................................................ 4–6
4.2.2 Theory of Operation .................................................................................................................................. 4–6
4.2.3 Viterbi Decoding Theory .......................................................................................................................... 4–7
4.3 Monitor and Control ....................................................................................................................................... 4–9
4.3.1 Non-Volatile Memory............................................................................................................................... 4–9
4.3.2 Remote Interface Specification............................................................................................ ..................... 4–10
4.3.3 M&C Theory of Operation........................................................................................................................ 4–10
4.3.4 Remote Interface Configuration................................................................................................................ 4–10
4.3.5 Modem Defaults........................................................................................................................................ 4–10
4.4 Digital Interfaces.............................................................................................................................................. 4–12
4.4.1 EIA-422/449 Interface............................................................................................................................... 4–12
4.4.1.1 Functional Description..................................................................................................................... 4–12
4.4.1.2 Specification..................................................................................................................................... 4–14
CHAPTER 5. MAINTENANCE.........................................................................................5–1
5.1 System Checkout.............................................................................................................................................. 5–1
5.1.1 Modulator Checkout.................................................................................................................................. 5–2
5.1.2 Demodulator Checkout ............................................................................................................................. 5–3
5.1.3 Test Points................................................................................................................................................. 5–6
5.1.3.1 Modulator Test Points...................................................................................................................... 5–6
5.1.3.2 Demod/M&C/Interface Test Points.................................................................................................. 5–7
5.2 Fault Isolation ..................................................................................................................................................5–8
5.2.1 Modulator Faults....................................................................................................................................... 5–10
5.2.1.1 Continuous Mode............................................................................................................................. 5–10
5.2.2 Demodulator Faults................................................................................................................................... 5–11
5.2.2.1 Burst Mode....................................................................................................................................... 5–11
5.2.3 Transmit Interface Faults .......................................................................................................................... 5–11
5.2.4 Receive Interface Faults............................................................................................................................ 5–11
5.2.4.1 Burst Mode....................................................................................................................................... 5–11
5.2.5 Common Equipment Faults....................................................................................................................... 5–12
5.3 Module Identification ...................................................................................................................................... 5–13
iv Rev. 1
SNM-1001 Network Control Modem Preface
5.4 Software Versions............................................................................................................................................ 5–13
5.5 Repackaging Requirements for Shipment..................................................................................................... 5–14
APPENDIX A. REMOTE CONTROL OPERATION ..........................................................A–1
A.1 General......................................................................................................................................................... A–2
A.2 Message Structure....................................................................................................................................... A–3
A.2.1 Start Character........................................................................................................................................... A–3
A.2.2 Device Address......................................................................................................................................... A–3
A.2.3 Command/Response.................................................................................................................................. A–4
A.2.4 End Character............................................................................................................................................ A–4
A.3 Configuration Commands/Responses........................................................................................................ A–5
A.3.1 Modulator.................................................................................................................................................. A–5
A.3.2 Demodulator.............................................................................................................................................. A–7
A.3.3 Interface .................................................................................................................................................... A–9
A.3.4 System....................................................................................................................................................... A–13
A.3.5 AUPC........................................................................................................................................................ A–13
A.4 Status Commands/Responses ..................................................................................................................... A–15
A.4.1 Configuration............................................................................................................................................ A–15
A.4.2 Error Performance..................................................................................................................................... A–31
A.5 Stored Faults................................................................................................................................................ A–32
Rev. 1 v
Preface SNM-1001 Network Control Modem
Figures
Figure 1-1. SNM-1001 Network Control Modem................................................................................................. 1–1
Figure 1-2. Typical NMS Configuration................................................................................................................ 1–3
Figure 1-3. Typical Network Control Channel Configuration ...............................................................................1–3
Figure 1-4. SNM-1001 Block Diagram................................................................................................................. 1–4
Figure 1-5. SNM-1001 Acquisition Performance ................................................................................................. 1–8
Figure 1-6. SNM-1001 Bit Error Rate Performance (Burst Mode)....................................................................... 1–9
Figure 2-1. Typical Rack Elevation....................................................................................................................... 2–3
Figure 2-2. Chassis Dimensional Drawing............................................................................................................ 2–3
Figure 2-3. SNM-1001 Rear Panel View .............................................................................................................. 2–4
Figure 3-1. SNM-1001 Front Panel View............................................................................................................. 3–1
Figure 4-1. Modulator Block Diagram.................................................................................................................. 4–2
Figure 4-2. Demodulator Block Diagram Burst Mode.......................................................................................... 4–5
Figure 4-3. Viterbi Decoder Block Diagram ......................................................................................................... 4–8
Figure 4-4. EIA-422/449 Diagram........................................................................................................................ 4–13
Figure 5-1. Typical Output Spectrum.................................................................................................................... 5–2
Figure 5-2. Typical Output Spectrum Noise......................................................................................................... 5–4
Figure 5-3. Typical Eye Constellations................................................................................................................. 5–5
Figure 5-4. SNM-1001 Fault Tree (Burst Mode).................................................................................................. 5–8
Figure 5-5. SNM-1001 Fault Tree (Continuous Mode)......................................................................................... 5–9
Tables
Table 1-1. Burst Mode Specifications................................................................................................................... 1–5
Table 1-2. Continuous Mode Specifications......................................................................................................... 1–6
Table 1-3. Burst Mode BER Specifications.......................................................................................................... 1–7
Table 2-1. Rear Panel Connectors ......................................................................................................................... 2–4
Table 4-1. M&C Jumper Settings (AS/4973)........................................................................................................ 4–2
Table 5-1. Adaptive Broadband Part Numbers for Various Modules ................................................................... 5–13
vi Rev. 1
SNM-1001 Network Control Modem Preface
About this Manual
This manual provides installat ion and operat ion info rmation for the Adaptive Broadband
SNM-1001 Network Control Modem. This is a technical document intended for earth
station engineers, technicians, and operators responsible for the operation and
maintenance of the SNM-1001 Network Control Modem.
Conventions and References
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
unsafe practices or risks of property damage.
WARNING
Metric Conversion
Metric conversion information is located on the inside back cover of this manual. This
information is provided to assist the operator in cross-referencing English to Metric
conversions.
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
Products names mentioned in this manual may be trademarks or registered trademarks of
their respective companies and are hereby acknowledged.
WARNING indicates a potentially hazardous situation that, if not avoided,
could result in death or serious injury.
Rev. 1 vii
Preface SNM-1001 Network Control Modem
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 Comtech EFData Customer Support
Department.
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 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:
Note:
For additional symbols, refer to “Cautions and Warnings” listed earlier in this
preface.
ACHTUNG: Zweipolige bzw. Neutralleiter-Sicherung
Alternating Current.
Fuse.
Safety Ground.
Chassis Ground.
viii Rev. 1
SNM-1001 Network Control Modem Preface
Warranty Policy
This Comtech EFData product is warranted against defects in material and workmanship
for a period of one year from the date of shipment. During the warranty period, Comtech
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 Comtech
EFData and all related custom, taxes, tariffs, insurance, etc. Comtech EFData is
responsible for the freight charges
the customer. Comtech EFData will return the equipment by the same method (i.e., Air,
Express, Surface) as the equipment was sent to Comtech EFData.
only
for return of the equipment from the factory to
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 repackag ing of
equipment for return to Comtech EFData.
No other warranty is expressed or implied. Comtech EFData 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. Comtech
EFData shall not be liable for any direct, indirect, special, incidental, or consequential
damages, whether based on contract, tort, or any other legal theory.
Disclaimer
Comtech EFData has reviewed this manual thoroughly in order that it will be an easy-touse 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, Comtech 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 Comtech EFData Customer Support Department.
Rev. 1 ix
Preface SNM-1001 Network Control Modem
This page has been intentionally left blank.
x Rev. 1
This chapter describes the SNM-1001 network control modem, referred to in this manual
as “the modem”.
1.1 Overview
The SNM-1001 Network Control Modem (Figure 1-1) is a fully integrated, digital
satellite network channel modem.
Chapter 1.
INTRODUCTION
1
Figure 1-1. SNM-1001 Network Control Modem
Rev. 1 1–1
Introduction SNM-1001 Network Control Modem
Using digital signal processing techniques, it functions as the network control channel
modem for Comtech EFData’s Bandwidth-on-Demand (BOD) Multimedia Integrated
Digital Access System (MIDAS).
Features of the SNM-1001 include the following:
• Fully integrated master control mode functionality
• 19.2 kbit/s, QPSK, 1/2 rate burst mode demodulator
• 19.2 kbit/s, QPSK, 1/2 rate continuous mode modulator
• Operational parameters stored in EEPROM
• 50/180 MHz operation
1.2 Mode of Operation
The SNM-1001 is an integral component of the MIDAS Network Management System
(NMS), providing the control channel communication path between the NMS and the
remote nodes.
The NMS transmits commands to the remote nodes through the SNM-1001, using a
continuous, TDM, outbound carrier. The remote nodes send requests and status messages
to the NMS using the slotted ALOHA burst inbound channel. This inbound channel
technology allows multiple remote nodes to share a single inbound carrier.
A typical NMS configuration is shown in Figure 1-2. A typical network control channel
configuration is shown in Figure 1-3.
1–2 Rev. 1
SNM-1001 Network Control Modem Introduction
)
NETWORK CONTROL MODEM
OPERATOR
WORKSTATION
OPTIONAL PRINTER
(USER SUPPLIED)
ETHERNET
NMS
CONTROLLER
EIA-422
EIA-232
EIA-232
(SNM-1001)
SNM -1001 Network Control Modem
TRANSMIT
TRAN SMIT
A
F
L
A
RECEIVE
RECEIVE
SDT -1200
A
U
R
L
COMMON
SATELLITE TERMIN AL
M
T
S
S
STORED
LinkSync MODEM
(SNM-1002)
ENTER
CLEAR
POWER ON
ENTER
TRANSMITTER ON
CARRIE R DET ECT
CLEAR
TEST MODE
TM
IF
(50-180 MHz)
RFT
Figure 1-2. Typical NMS Configuration
BURST
CONTINUOUS
NMS SITE
(SNM-1001)
TDMA INBOUND
TDN OUTBOUND
REMOTE 3
(SNM-1010)
REMOTE 1
(SNM-1000)
REMOTE 2
(SNM-1000)
Figure 1-3. Typical Network Control Channel Configuration
REMOTE 4
(SNT-1020
Rev. 1 1–3
Introduction SNM-1001 Network Control Modem
1.2.1 Description
The SNM-1001 is a complete, self-contained unit in a standard 1 Unit (1U) 19”
(48.26 cm) rack-mountable enclosure weighing approximately 10 lbs. (8.63 kg.)
All Monitor and Control (M&C) functions and indicators for operation of the modem, as
well as the display Printed Circuit Board (PCB), are located on the front panel.
The chassis contains the power supply; a fan is located on the rear panel.
A system block diagram is shown in Figure 1-4.
SNM-1001
CUSTOMER
DATA I/O
EXT.
CLOCK
ALARMS
FORM C
CONTACTS
REMOTE
SERIAL
INTERFACE
NETWORK
CONTROL MODEM
J8
J8
J7
J6
INTERFACE
DISPL AY AND
COMMAND BUS
M&C
KEYPAD
DATA
CLK
SCT
DATA
CLK
ENCODER/
MODULATOR
M&C
POWER
SUPPLY
M&C
DEMOD/
DECODER
IF OUTPUT
CP1
50 TO 90 MHz
100 TO 180 MHz
-5 TO -30 dBm
90 TO 264 VAC,
47 TO 63 Hz
IF INPUT
CP2
50 TO 90 MHz
100 TO 180 MHz
-30 TO -55 dBm
TRANSMIT
RF
EQUIPMENT
RECEIVE
RF
EQUIPMENT
ANTENNA
FRONT
PANEL
REMOTE
(OPT.)
Figure 1-4. SNM-1001 Block Diagram
1.3 Options
The following option is available for the SNM-1001:
• ± 48 VDC power
1–4 Rev. 1
SNM-1001 Network Control Modem Introduction
1.4 Specifications
Table 1-1 and Table 1-2 list the operating specifications of the modem in Burst mode and
Continuous mode, respectively.
Table 1-1. Burst Mode Specifications
General Specifications
Operating Frequenc y Range 50 to 180 MHz, synthesiz e d in 100 H z st e ps
Type of D e modulation QPSK
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 speci f i e d ac quis ition ra ng e
Bit Error Rate See Table 1-3
Digital Interfac e EIA-422/449 on 37-pin D
Digital Data Rate:
QPSK, 1/2 Rate 19.2 kbit/s
Doppler Buffer N/A
Forward Error Correc tion Convolutional encoding with s oft decision, K=7 Viterbi
decoding.
Data Descrambling Selectable or none, 215-1, synchronous
Prime Power 90 to 264 VAC auto select, 47 to 63 H z , 50W maxim um,
fused at 2A
Size 1.75” H x 19.0” W x 20.1” D ( 4.44 H x 48.26 W x 51.0 D
cm) (see Figure 2-2)
Operating Temperature
Storage Temperature
Humidity 0 to 95% noncondensing
Diagnostic Feature s IF Loopback
Additional Demodulator Specifications
Input Power (Desired Ca r rie r ) -30 to -55 dBm (com posite )
Input Impedance 75Ω standard
Input Return Loss 20 dB
Carrier Acquis ition Ra ng e
Clock Acquisition Ra ng e
Acquisition Tim e < 30 ms
Directed Sweep N/A
0° to 55°C (32° to 131° F)
-55° to +70°C (-131° to 158° F)
RF Loopback
Baseband Loopback (bi-directional, elect ric a l)
Fault Monitoring
Bit Error Rate Monitoring
Remote Control via Serial Port
+30 dB power within 2 MH z from desired c a rr ie r
+40 dB power outside of 2 MHz from de s ir ed c a r ri e r
– 5 dBm maximum composite
4 kHz minim um
±
100 PPM
±
Rev. 1 1–5
Introduction SNM-1001 Network Control Modem
Table 1-2. Continuous Mode Specifications
General Specifications
Operating Frequenc y Range 50 to 180 MHz, synthesiz e d in 100 H z st e ps
Type of Modula tion QPSK
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 spec ified acquisition range
Phase Noise In accordance with IESS-308
Digital Interface
(Field Changeable Plug-in Modules )
One Interface per Module)
Digital Data Rates:
QPSK, 1/2 Rate 19.2 kbit/s
Doppler Buffer Program mable from 64 to 65536 bits , or from 1 to 50 ms
Forward Error Correc tion Convolutional encoding with s oft decision K=7 Viterbi
Data Scrambling CCITT V.35
Prime Power 90 to 264 VAC auto select, 47 to 63 H z , 50W maxim um,
Size 1.75” H x 19.0” W x 20.1” D ( 4.44 H x 48.26 W x 51.0 D
Operating Temperature
Storage Temperature
Humidity 0 to 95% noncondensing
Diagnostic Feature s IF Loopback
Additional Modulator Specifications
Output Power -5 to -30 dBm, adjustable in 0.1 dB st e ps
Output Spurious and Harmonic s -55 dBc in 4 kHz BW in- ba nd (50 to 180 MH z )
Output Impedance 75Ω standard
Output Return Loss 20 dB
Output Frequency Stability
Data Clock Source Internal or external
Internal Data Clock Stability
EIA-422/449 on 37-pin D
total depth
decoding, Sequential decoding
fused at 2A
cm) (see Figure 2-2)
0° to 55°C (32° to 131° F)
-55° to +70°C (-131° to 158° F)
RF Loopback
Baseband Loopback (bi-directional, elect ric a l)
Fault Monitoring
Bit Error Rate Monitoring
Remote Control via Serial Port
-55 dBc in 4 kHz BW out- of-band (0 to 500 MHz)
10 PPM
±
External clock
10 PPM
±
100 PPM and < 5% jitter
±
1–6 Rev. 1
SNM-1001 Network Control Modem Introduction
Remote Control Specifications
Serial Interface EIA-232, baud rate is19,200 bit/s.
Signals Controlled/Monitored Transmit Frequency
Receive Frequency
Transmit Power
Transmitter ON/OFF
IF Loopback
RF Loopback
Baseband Loopba c k
Scrambler ON/OFF
Descrambler ON/OFF
Sweep Center
Filter Mask
Raw Error Rate
Corrected Bit Error Rate
Receive E
b/N0
TX Clock Internal/External
RX Clock Normal/Invert
Receive Signal Level
Receive Carrier Detect
Power Supply Voltage s
Fault Status
Stored Fault Status
Configuration Retention Will maintain current config uration for at least one ye ar without
power
Addressing Programmable to 1 of 255 possibilitie s
Address 0 res e rved for global addr e s s ing
The Bit Energy-to-Noise Ratio (Eb/N0) required to achieve 10-6 to 10-9 bit error rate in
Burst mode is listed in Table 1-3.
Table 1-3. Burst Mode BER Specifications
Eb/N
0
6 dB 6.4
8 dB 1.1
BER PER ACQ
-4
-4
6.3
9.1
-2
-3
93%
99%
Notes:
1. Burst mode performance is measured with a 100 byte packet.
2. BER values are measured with a packet long enough to allow 100 errors.
Rev. 1 1–7
Introduction SNM-1001 Network Control Modem
Acquisition performance of the modem is shown in Figure 1-5.
Figure 1-5. SNM-1001 Acquisition Performance
1–8 Rev. 1
SNM-1001 Network Control Modem Introduction
The Bit Error Rate (BER) performance of the modem in Burst mode is shown in
Figure 1-6.
1
-1
10
-2
10
-3
10
BER
-4
10
BER
-5
10
-6
10
-7
10
-8
10
3.0 4.0 5.0 6.0
BER
7.0 8.0 9.0 10.0 11.0
E
(dB)
b/N0
Figure 1-6. SNM-1001 Bit Error Rate Performance (Burst Mode)
Rev. 1 1–9
Introduction SNM-1001 Network Control Modem
This page is intentionally left blank.
1–10 Rev. 1
This chapter contains the following information:
• Unpacking
• Installation
• System options
• External connections
2.1 Unpacking
The modem and manual are packaged in a pre-formed, reusable cardboard carton
containing foam spacing for maximum shipping protection.
Chapter 2.
INSTALLATION
2
The circuit cards are contained in the modem chassis.
Do not use any cutting tool that will extend more than 1” (2.54cm) into the
container and cause damage to the modem.
CAUTION
To remove 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.
Rev. 1 2–1
Installation SNM-1001 Network Control Modem
4. Save the packing material for reshipment purposes.
5. Inspect the equipment for damage incurred during shipment.
6. Check the equipment against the packing list to ensure that the shipment is
complete.
2.2 System Installation
To install the modem:
1. Mount the modem chassis in the assigned position in the equipment rack. Refer
to
Figure 2-1 for a typical rack elevation for an M:N system. For a custom rack
installation, refer to the chassis dimensional drawing in Figure 2-2.
Connect the cables to the appropriate locations on the rear panel. Section 2.3
contains a description of connector pinouts, placements, and functions.
Before turning on the power switch, read and become familiar with Chapter 3.
Verify that all jumper settings are correctly set for remote operation. Jumper
settings are listed in Table 4-1.
Turn on the power switch, located on the rear panel.
Check for proper TX output signal level and spectrum.
Check for proper RX input signal level and spectrum.
If there is any problem with the installation, refer to Chapter 5 for instructions on
how to troubleshoot the system.
2–2 Rev. 1
SNM-1001 Network Control Modem Installation
SNM -1001 Network
Figure 2-1. Typical Rack Elevation
19.0
(48.26)
1.75
(4.5)
S N M -1001 N etw ork C ontrol M odem
20.10
(51.0)
1.25
(3.17)
Figure 2-2. Chassis Dimensional Drawing
Rev. 1 2–3
Installation SNM-1001 Network Control Modem
2.3 External Modem Connectors
Connections between the modem and other equipment are made through five connectors.
These connectors are listed in Table 2-1 and their locations are shown in Figure 2-3. The
use of each connector is described in the following paragraphs.
Table 2-1. Rear Panel Connectors
Name Ref. Design Function Connector Type
AC POWER None AC Power Input Standard
DATA I/O J8 DATA Input/Output ( I/O )
EIA-422/449
AGC None AGC Test Point Test Point
FAULTS J7 FORM-C Fault Relay Contacts 9-pin Female D
REMOTE J6 Remote Interf a ce 9-pin Female D
TX IF OUTPUT CP1 TX IF Output BNC
RX IF INPUT CP2 RX IF Input BNC
CHASSIS GND None Chassis Ground #10-32 Stud
Various
37-pin D
Figure 2-3. SNM-1001 Rear Panel View
2.3.1 DATA I/O Interface (J8)
The DATA I/O interface connector is used to interface data input and output signals to
and from the modem. J8 connects to the customer terrestrial equipment directly, or
through a protection switch. The modem operates with a single interface configuration.
The DATA I/O interface is EIA-422/449.
2–4 Rev. 1
SNM-1001 Network Control Modem Installation
2.3.1.1 EIA-422/449 Interface Connector Pinouts
The EIA-422/449 interface is provided on a 37-pin female D connector accessible on the
rear panel of the modem. Screw locks are provided for mechanical security of the mating
connector.
Signal Function Name Pin #
Send Data SD-A
SD-B
Send Timing ST-A
ST-B
Receive Data RD-A
RD-B
Request to Send EIA-A
EIA-B
Receiver Timing RT-A
RT-B
Clear to Send CS-A
CS-B
Data Mode DM-A
DM-B
Receiver Ready RR-A
RR-B
Terminal Timing TT-A
TT-B
Master Clock (input) MC-A
MC-B
Demod Fault – 21
Mod Fault – 3
Signal Ground SG 1, 19, 20, 37
(See Note)
(See Note)
(See Note)
(See Note)
4
22
5
23
6
24
7
25
8
26
9
27
11
29
13
31
17
35
16
34
Note:
The EIA and CS lines are jumpered together on the demod/M&C card
(AS/4973-2), since the modem does not support polled operation.
Rev. 1 2–5
Installation SNM-1001 Network Control Modem
2.3.2 Remote (J6)
The remote connector allows the user to interface the Monitor and Control (M&C)
functions with a remote location. This interface is EIA-232-C. For further discussion on
the remote interface, refer to Chapter 4.
The remote interface is provided on a 9-pin female D connector. Screw locks are
provided for mechanical security of the mating connector.
The remote connector is a Data Circuit Terminating Equipment (DCE) interface.
There are jumpers that must be set on the demodulator board to select the EIA-232-C
remote interface. Refer to Chapter 4 for their location and configuration information.
EIA-232-C
4-Wire and 2-Wire Mode
Pin # Name
1
2RD (RX)
3TD (TX)
4
5GND
6DSR
7RTS
8CTS
9
2–6 Rev. 1
SNM-1001 Network Control Modem Installation
2.3.3 Faults (J7)
The fault connector on the modem is used to provide FORM-C contact closures for the
purpose of fault reporting. There are three FORM-C summary fault contacts:
• Modulator
• Demodulator
• Common equipment
To obtain a system summary fault, connect all FORM-C contacts in parallel.
The fault interface is provided on a 9-pin female D connector. Screw locks are provided
for mechanical security of the mating connector. The pinout of the connector is as
follows:
Pin # Name Function
1 NO C ommon equipment is not f a ulte d
2COM
3 NC Common equipment is faulted
4 NO Modula tor is not faulted
5COM
6 NC Modulator is faulted
7 NO D e modulator is not faulted
8COM
9 NC Demodulator is faulted
Note:
A connection between the common (COM) and normally open (NO) contacts
indicates no fault.
2.3.4 TX IF Output (CP1)
CP1 is the transmit IF connector. The output impedance is 75Ω. The output power level
is -5 to -30 dBm, in 0.1 dB steps.
In normal operation, the output will be a QPSK modulated result of the DATA I/O
connector, between 50 and 180 MHz.
Rev. 1 2–7
Installation SNM-1001 Network Control Modem
2.3.5 RX IF Input (CP2)
CP2 is the receive IF connector. The input impedance is 50Ω (75Ω optional).
In normal operation, the desired carrier signal level should read between -30 and 55 dBm.
Signals between 50 and 180 MHz are selected and demodulated to produce clock and
data at the DATA I/O connector.
2.3.6 AC Power
The AC power is supplied to the modem by a standard, detachable, non-locking, 3-prong
power cord. Normal input voltage is 90 to 264 VAC, 47 to 63 Hz. The modem will
automatically switch between ranges. Maximum power consumption is less than 40W.
2.3.7 DC Power
DC power is available as an option. The DC power is supplied to the modem by a 3
position terminal block. Normal input voltage is ± 48 VDC,
consumption is less than 40W.
2.3.8 Chassis GND
A #10-32 stud is available on the rear panel for the purpose of connecting a common
chassis ground between all of the equipment.
Note:
The safety ground is provided through the AC power connector.
2.3.9 AGC Test Point
The Automatic Gain Control (AGC) test point is a BNC connector on the back of the
modem chassis. This feature allows the user to monitor the AGC.
10%. Maximum power
±
2–8 Rev. 1
This chapter describes the front panel operation and clocking options of the modem.
3.1 Front Panel
The front panel of the modem (Figure 3-1) is locked out. It displays SNM-1001. The
NMS sets all values.
S N M -1001 N etw o rk C o n tro l M o d em
Chapter 3.
OPERATION
3
Figure 3-1. SNM-1001 Front Panel View
Rev. 1 3–1
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