Comtech EF Data CRS-280L, CRS-280 Installation And Operation Manual

CRS-280

70/140 MHz IF Switch for 1:N Redundancy

CRS-280L

L-Band IF Switch for 1:N Redundancy

Installation and Operation Manual

Part Number MN-CRS-280/280L

Revision -

IMPORTANT NOTE: The information contained in this document supersedes all previously published
information regarding this product. Product specifications are subject to change without prior notice.

CRS-280/280L IF Switch for 1:N Redundancy

Revision -

Copyright © 2018 Comtech EF Data. All rights reserved. Printed in the USA.
Comtech EF Data, 2114 West 7th Street, Tempe, Arizona 85281 USA, 480.333.2200, FAX: [phone]

Revision History

Rev

- 2-2018 Initial Release.

Date

Description

Note: This manual supersedes MN/CRS280L.IOM.

MN-CRS-280/280L

C-280/280L IF Switch for 1:N Redundancy
Revision -

TABLE OF CONTENTS

PREFACE ........................................................................................................................ I

About this Manual ........................................................................................................................................ i

Related Documents ...................................................................................................................................... i

Conventions and References..................................................................................................................... ii

Patents and Trademarks ............................................................................................................................ ii

Warnings, Cautions, and Notes ................................................................................................................. ii

Recommended Standard Designations .................................................................................................... iii

Metric Conversion ..................................................................................................................................... iii

Electrical Safety ......................................................................................................................................... iii

Electrical Safety Notice ............................................................................................................................. iii

Electrical Safety Complianc e .................................................................................................................... iii

Fuses iv

Environmental ............................................................................................................................................ iv

Installation .................................................................................................................................................. iv

Telecommunications Terminal Equipment Directive ............................................................................... v

Federal Communications Commission (FCC).......................................................................................... v

International Symbols ................................................................................................................................. v

EMC (Electromagnetic Compatib ility) ....................................................................................................... v

EN55022 - 1997 Compliance .................................................................................................................... v

EN55024 - 1998 Compliance .................................................................................................................... v

Product Support ......................................................................................................................................... vi

Comtech EF Data Headquarters ............................................................................................................... vi

Warranty Policy ......................................................................................................................................... vii

Limitations of Warranty ............................................................................................................................. vii

Exclusive Remedies ................................................................................................................................ viii

CHAPTER 1. INTRODUCTION ................................................................................ 1–1

1.1 Overview ...................................................................................................................................... 1–1

1.1.1 Compatibility ............................................................................................................................. 1–3

1.2 Physical Description ................................................................................................................... 1–4

1.2.1 Front Panel ............................................................................................................................... 1–4

1.2.2 Rear Panel ................................................................................................................................ 1–5

1.2.3 Dimensional Envelope .............................................................................................................. 1–6

1.3 Summary of Specifications ........................................................................................................ 1–8

1.3.1 CRS-280L Typical Insertion Loss Graphs ............................................................................... 1–10

CHAPTER 2. INSTALLATION .................................................................................. 2–1

2.1 Unpacking and Inspection ......................................................................................................... 2–1

2.2 Mounting ...................................................................................................................................... 2–2

CHAPTER 3. CONNECTOR PINOUTS .................................................................... 3–1

3.1 Connector Overview ................................................................................................................... 3–1

3.1.1 CRS-280 Connector Overview ................................................................................................. 3–2

Table of Contents TOC-1 MN-CRS-280/280L

C-280/280L IF Switch for 1:N Redundancy
Revision -

3.1.2 CRS-280L Connector Overview................................................................................................ 3–4

3.2 Front Panel Connectors ............................................................................................................. 3–6

3.3 Rear Panel Control Connectors ................................................................................................. 3–6

3.3.1 CRS-280 Switch Control Interface Connector .......................................................................... 3–6

3.3.1.1 J1 CRS Control Interface Connector, DB-25F .............................................................. 3–6

3.3.2 CRS-280L Switch Control Interface Connectors ...................................................................... 3–7

3.3.2.1 J1 CRS Control Interface Connector, DB-25F .............................................................. 3–7

3.3.2.2 J2 SMS Control Interface Connector, DB-15M ............................................................. 3–7

3.3.2.3 Power / Ground Connections ........................................................................................ 3–8

3.3.2.3.1 Alternating Current (AC) Power Connectors .................................................. 3–8

3.3.2.3.2 Direct Current (DC) Power Connectors (optional) ......................................... 3–8

3.3.2.4 Ground Connector ......................................................................................................... 3–9

CHAPTER 4. CABLES AND CONNECTIONS ......................................................... 4–1

4.1 Overview ...................................................................................................................................... 4–1

4.2 Control Cable Connections ........................................................................................................ 4–2

4.2.1 SMS-7000 1:8 Modem Protection Switch Control Cable Connection ...................................... 4–3

4.2.2 CRS-400 1:8 Redundancy Switch Control Cable Connection .................................................. 4–3

4.2.3 CRS-300 1:N Redundancy Switch Control Cable Connection ................................................. 4–3

4.2.4 CRS-500 M:N Redundancy System Control Cable Connection ............................................... 4–4

4.3 Cable Connections .................................................................................................................... 4–11

4.3.1 CRS-280 IF Cable Connections ............................................................................................. 4–11

4.3.2 CRS-280L L-Band IF Cable Connections ............................................................................... 4–11

4.3.3 L-Band IF Cable Characteristics ............................................................................................. 4–11

4.3.4 L-Band Switch-to-Modem Cabling Requirements .................................................................. 4–11

4.3.5 L-Band Uplink/Downlink Cable Connections .......................................................................... 4–12

CHAPTER 5. REDUNDANCY SYSTEM CONFIGURATION / OPERATION ............ 5–1

5.1 Overview ...................................................................................................................................... 5–1

5.2 CRS-280L Input Power Cord Connections ............................................................................... 5–1

5.3 1:N Redundancy System Power-up Sequence ........................................................................ 5–2

5.3.1 CRS-280L operations with the CRS-500 M:N Redundancy System ........................................ 5–2

APPENDIX A . CABLE DRAWINGS ......................................................................... A-1

A.1 Introduction ................................................................................................................................. A-1

A.2 Control Interface Cables ............................................................................................................. A-2

A.2.1 SMS-7000 Control Cable ...........................................................................................................A-3

A.2.2 CRS-400/CRS-300 Control Cable .............................................................................................A-4

A.2.3 CRS-500 Control Cable .............................................................................................................A-5

A.3 IF Interface Cable, Type ‘N’ 50Ω ................................................................................................. A-6

APPENDIX B. CRS-280L POWER SUPPLY MODULE REPLACEMENT ............... B–1

B.1 Introduction ................................................................................................................................ B–1

B.2 Power Supply Module Removal Procedure ............................................................................. B–3

B.3 Power Supply Module Installation Procedure ......................................................................... B–5

Table of Contents TOC-2 MN-CRS-280/280L

C-280/280L IF Switch for 1:N Redundancy
Revision -

LIST OF FIGURES

Figure 1-1. CRS-280 70/140 MHz IF Switch for 1:N Redundancy ........................................................... 1–1

Figure 1-2. CRS-280L L-Band IF Switch for 1:N Redundancy ................................................................. 1–1

Figure 1-3. 1:10 Redundanc y w/CRS-280L – System-level Block Diagram ............................................. 1–3

Figure 1-4. CRS-280 Front Panel ............................................................................................................. 1–4

Figure 1-5. CRS-280L Front Panel (1:10 Configuration shown) ............................................................... 1–4

Figure 1-6. CRS-280 Rear Panel .............................................................................................................. 1–5

Figure 1-7. CRS-280L Rear Panel ............................................................................................................ 1–5

Figure 1-8. CRS-280 (70/140 MHz) IF Switch Dimensional Envelope ..................................................... 1–6

Figure 1-9. CRS-280L (L-Band) IF Switch Dimensional Envelope ........................................................... 1–7

Figure 1-10. Graph 1 – Downlink Input to Rx Output .............................................................................. 1–10

Figure 1-11. Graph 2 – Downlink Input to Backup Rx Output ................................................................. 1–11

Figure 1-12. Graph 3 – Backup Input to Selected Uplink Output............................................................ 1–12

Figure 1-13. Graph 4 – Tx Input to Associated Uplink Output ................................................................ 1–13

Figure 3-1. CRS-280 Connectors ............................................................................................................. 3–2

Figure 3-2. CRS-280L Connectors ............................................................................................................ 3–4

Figure 4-1. SMS-7000 to CRS-280L Control Cable Connection .............................................................. 4–5

Figure 4-2. CRS-400 to CRS-280L Control Cable Connection ................................................................. 4–6

Figure 4-3. CRS-300 to CRS-280 Control Cable Connection ................................................................... 4–7

Figure 4-4. CRS-300 to CRS-280L Control Cable Connection ................................................................. 4–8

Figure 4-5. CRS-500 to CRS-280 Control Cable Connection ................................................................... 4–9

Figure 4-6. CRS-500 to CRS-280L Control Cable Connection ............................................................... 4–10

Figure A-1. CRS-280L  SMS-7000 Data Switch Un it (DSU) Contr ol Cab le (CEFD P/N CA/5343-1) ... A-3

Figure A-2. CRS-280L  CRS-400, CRS-300 Control Cable (CEFD P/N CA/WR0066) ......................... A-4

Figure A-3. CRS-280/280L  CRS-500 Data Switch Unit (DSU) Control Cable

(CEFD P/N CA-0021666) .................................................................................................................. A-5

Figure A-4. Type ‘N’ 50Ω IF Coax Cable (CEFD P/N CA/RF10453-x)...................................................... A-6

Figure B-1. CRS-280L Rear Panel (shown with PL/10207-1 AC Modules) .............................................. B–2

LIST OF TABLES

Table 1-1. IF Switch Compatibility Table ................................................................................................... 1–2

Table 3-1. CRS-280 External Connectors (Front and Rear Panel) ........................................................... 3–3

Table 3-2. CRS-280L External Connectors (Front and Rear Panel) ......................................................... 3–5

Table of Contents TOC-3 MN-CRS-280/280L

C-280/280L IF Switch for 1:N Redundancy
Revision -

Acronym List

Acronym Description

AC Alternating Current

CSU Control Switch Unit

DC Direct Current

ISU IF Switch Unit

LED Light Emitting Diode

Table of Contents TOC-4 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

PREFACE

About this Manual

This manual provides installation and operation information for the Comtech EF Data CRS-280L
L-Band IF Switch, designed for use as a companion product in Comtech 1:N Redundancy Systems.
This is a technical document intended for earth station engineers, technicians, and operators
responsible for the operation and maintenance of the CRS-280/280L.

Comtech EF Data has reviewed this manual thoroughly in order to provide 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, Comtech EF Data
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.

This is an informational document intended for the persons responsible for the operation and
maintenance of the modem.

Related Documents

• Comtech EF Data CRS-300 1:10 Redundancy Switch Installation and Operation
Manual

• Comtech EF Data CRS-500 M:N Redundancy System Installation and Operation
Manual

• Comtech EF Data SMS-7000 1:8 Modem Pr o te ct io n Swit ch In st allation and
Operation Manual (legacy product, no longer in production)

• Comtech EF Data CRS-400 1:8 Redundancy Switch Installation and Operation
Manual (legacy product, no longer in production)

Preface i MN-PCB-4300A

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Conventions and References

Patents and Trademarks

See all of Comtech EF Data's Patents and Patents Pending at http://patents.comtechefdata.com.
Comtech EF Data acknowledges that all trademarks are the property of the trademark owners.

Warnings, Cautions, and Notes

A WARNING gives information about a possible hazard that MAY CAUSE DEATH
or SERIOUS INJURY.

A CAUTION gives information about a possible hazard that MAY CAUSE INJURY
or PROPERTY DAMAGE.

A NOTE gives important information about a task or the equipment.

A REFERENCE directs the user to additional information about a task or the
equipment.

Examples of Multi-Hazard Notices

Preface ii MN-PCB-4300A

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Recommended Standard Designations

Electronic Industries Association (EIA) designations supersede Recommended Standard (RS)
designations. Reference to the old RS designations (e.g., RS-232) may appear where it might
concern actual text displayed on the unit’s rear panel, Serial Interface, or Web Server Interface
pages. All other references in the manual use the EIA designations.

Metric Conversion

Metric conversion information is provided on the inside back cover of this manual. Comtech EF
Data provides this information to assist the user in cross-referencing non-Metric to Metric
conversions.

Electrical Safety

Electrical Safety Notice

Double pole / neutral fusing is used on the prime power supply input.

This equipment is designed to minimize exposure of personnel to hazards. For further information,
contact the Comtech EF Data Customer Support Department. The persons responsible for the
operation and maintenance of the equipment must:

• Know how to work around, with, and on high voltage equipment.

• Exercise every precaution to ensure personnel safety.

• Exercise extreme care when working near high voltages.

• Be familiar with the warnings presented in this manual.

Electrical Safety Compliance

The CRS-280L has been shown to comply with the following safety standard:

• EN60950: Safety of Information Technology Equipment, including electrical business
machines

The equipment is rated for operation over the range 90-264 volts AC per each power supply. Each
has a maximum power consumption of 25 Watts and draws a maximum of 0.75 Amps rms max @
90 Volts AC, and 0.35 Amps rms max @ 230 Volts AC.

Optionally, the equipment is rated for operation over the range of 36-72 volts DC per ea ch sup ply .
Each has a maximum power consumption of 25 Watts and draws a maximum of 6.25 Amps.

Preface iii MN-PCB-4300A

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Fuses

FOR CONTINUED OPERATOR SA FETY, ALWAYS REPLACE THE FUSES WITH
THE CORRECT TYPE AND RATING.

The AC-powered CRS-280L is outfitted with two power supplies, each containing two fuses – one
each for line and neutral connections. These are contained within the body of each IEC power inl et
connector, behind a small plastic flap.

• For 230 volt AC operation, use T2.5A, 20mm fuses.

• For 115 volt AC operation, use T5.0A fuses, slow blow, P/N 5ASB-IEC.

The optionally DC-powered CRS-280L is outfitted with two power supplies. Each power
supply contains one fuse installed into a fuse holder.

• For 48 volt DC operation, use T6.25A 3AG fuses.

Environmental

The CRS-280L must not be operated in an environment where the unit is exposed to extremes of
temperature outside the ambient range 0 to 50°C, precipitation, condensation, or humid
atmospheres above 95% RH, altitudes (non-pressurized) greater than 2000 meters, excessive dust
or vibration, flammable gases, corrosive or explosive atmospheres.

Operation in vehicles or other transportable installations that are equipped to provide a stable
environment is permitted. If such vehicles do not provide a stable environment, safety of the
equipment to EN60950 may not be guaranteed.

Installation

The installation and connection to the line supply must be made in compliance to local or national
wiring codes and regulations.

The CRS-280L is designed for connection to a power system that has separate ground, line and
neutral conductors. The equipment is not designed for connection to a power system that has no
direct connection to ground.

The CRS-280L is shipped with line inlet cables suitable for use in the country of operation. If it is
necessary to replace these cables, ensure the replacement has an equivalent specification.
Examples of acceptable ratings for the cable include HAR, BASEC and HOXXX-X. Examples of
acceptable connector ratings include VDE, NF-USE, UL, CSA, OVE, CEBEC, NEMKO, DEMKO,
BS1636A, BSI, SETI, IMQ, KEMA-KEUR and SEV.

Preface iv MN-PCB-4300A

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Telecommunications Terminal Equipment Directive

In accordance with the Telecommunications Terminal Equipment Directive 91/263/EEC, this
equipment should not be directly connected to the Public Telecommunications Network.

Federal Communications Commission (FCC)

This equipment has been tested and found to comply with the limits for a Class A digital device,
pursuant to Part 15 of the FCC rules. These limits are designed to provide reasonable protection
against harmful interference when the equipment is operated in a commercial environment.

This equipment generates, uses, and can radiate radio frequency energy. If not installed and used
in accordance with the instruction manual, it may cause harmful interference to radio
communications. Operation of this equipment in a residential area is likely to cause harmful
interference; in which case, users are required to correct the interference at their own expense.

International Symbols

International Symbols
Symbol Definition Symbol Definition

~ Alternating Current

Fuse

EMC (Electromagnetic Compatibility)

This is a Class A product. In a domestic environment, it may cause radio interference that requires
the user to take adequate protection measures.

EN55022 - 1997 Compliance

This equipment meets the radio disturbance characteristic specifications for information technology
equipment as defined in EN55022-1997.

EN55024 - 1998 Compliance

Protective Earth

Chassis Ground

This equipment meets the EMC/immunity characteristics for the limits and methods of
measurement for information technology equipment per EN55024-1998.

Preface v MN-PCB-4300A

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

To ensure that the CRS-280L continues to comply with these standards,
observe the following instructions:

Connections to the transmit and receive IF ports (‘N’ type female connectors) should be made using
a good quality coaxial cable; for example, RG213/U.

The 'D' type connec to r a ttached to the rear panel must have a back-shell that provides continuous
metallic shielding. Cable with a continuous outer shield (either foil or braid, or both) must be used,
and the shield must be bonded to the back-shell.

The equipment must be operated with both AC module panels assembled firmly to the rear of the
chassis at all times. If it becomes necessary to remove either AC module, the user should ensure
that the cover is correctly re-fitted before normal operation commences.

Product Support

For all product support, please call:

+1.240.243.1880
+1.866.472.3963 (toll free USA)

By email:

[e-mail]

Comtech EF Data Headquarters

http://www.comtechefdata.com
Comtech EF Data Corp.
2114 West 7th Street
Tempe, Arizona USA 85281
+1.480.333.2200

Preface vi MN-PCB-4300A

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Warranty Policy

Comtech EF Data products are warranted against defects in material and workmanship for a
specific period from the date of shipment, and this period varies by product. In most cases, the
warranty period is two years. During the warranty period, Comtech EF Data will, at its option, repair
or replace products that prove to be defective. Repairs are warranted for the remainder of the
original warranty or a 90 day extended warranty, whichever is longer. Contact Comtech EF Data for
the warranty period specific to the product purchased.

For equipment under warranty, the owner is responsible for freight to Comtech EF Data and all
related customs, taxes, tariffs, insurance, etc. Comtech EF Data is responsible for the freight
charges only for return of the equipment from the factory to the owner. Comtech EF Data will return
the equipment by the same method (i.e., Air, Express, Surface) as the equipment was sent to
Comtech EF Data.

All equipment returned for warranty repair must have a valid RMA number issued prior to return and
be marked clearly on the return packaging. Comtech EF Data strongly recommends all equipment
be returned in its original packaging.

Comtech EF Data Corporation’s obligations under this warranty are limited to repair or replacement
of failed parts, and the return shipment to the buyer of the repaired or replaced parts.

Limitations of Warranty

The warranty does not apply to any part of a product that has been installed, altered, repaired, or
misused in any way that, in the opinion of Comtech EF Data Corporation, would affect the reliability
or detracts from the performance of any part of the product, or is damaged as the result of use in a
way or with equipment that had not been previously approved by Comtech EF Data Corporation.

The warranty does not apply to any product or parts thereof where the serial number or the serial
number of any of its parts has been altered, defaced, or removed.

The warranty does not cover damage or loss incurred in transportation of the product.
The warranty does not cover replacement or repair necessitated by loss or damage from any cause

beyond the control of Comtech EF Data Corporation, such as lightning or other natural and weather
related events or wartime environments.

The warranty does not cover any labor involved in the removal and or reinstallation of warranted
equipment or parts on site, or any labor required to diagnose the necessity for repair or
replacement.

The warranty excludes any responsibility by Comtech EF Data Corporation for incidental or
consequential damages arising from the use of the equipment or products, or for any inability to use
them either separate from or in combination with any other equipment or products.

A fixed charge established for each product will be imposed for all equipment returned for warranty
repair where Comtech EF Data Corporation cannot identify the cause of the reported failure.

Preface vii MN-PCB-4300A

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Exclusive Remedies

Comtech EF Data Corporation’s warranty, as stated is in lieu of all other warranties, expressed,
implied, or statutory, including those of merchantability and fitness for a particular purpose. The
buyer shall pass on to any purchaser, lessee, or other user of Comtech EF Data Corporation’s
products, the aforementioned warranty, and shall indemnify and hold harmless Comtech EF Data
Corporation from any claims or liability of such purchaser, lessee, or user based upon allegations
that the buyer, its agents, or employees have made additional warranties or representations as to
product preference or use.

The remedies provided herein are the buyer’s sole and exclusive remedies. Comtech EF Data shall
not be liable for any direct, indirect, special, incidental, or consequential damages, whether based
on contract, tort, or any other legal theory.

Preface viii MN-PCB-4300A

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Chapter 1. INTRODUCTION

1.1 Overview

Figure 1-1. CRS-280 70/140 MHz IF Switch for 1:N Redundancy

Figure 1-2. CRS-280L L-Band IF Switch for 1:N Redundancy

Introduction 1–1 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy

CDM-625/625A

CDM-700
CDM-Qx/QxL

Revision -

The CRS-280 (70/140 MHz) IF Switch (Figure 1-1) provides complete isolation of the IF signals.
The Redundant Modem’s IF signals are routed to the Traffic Modem’s IF path when the Switch
RMI is online. The Switch automatically senses the presence of the CRS-280. The Switch, upon
switching, leaves the offline modem with its IF on, and the CRS-280’s relays isolate any
undesired signals.

The CRS-280 (70/140 MHz) IF Switch is necessary when one or more modems within the
redundancy system connect to more than one up/down converter. This occurs when the modems
connect to more than one transponder on the same antenna polarization, or when modem
redundancy needs to span two or more polarizations or antennas.

The CRS-280L (L-Band) IF Swit c h ( Figure 1-2) is des igned to suppor t redundancy systems
featuring one Redundant (backup) Modem and up to 10 Traff ic Modems ( prime channels).
Operation of the CRS-280L is c ontr olled by the s witc hing s ystem to which it is connected.

The CRS-280L (L-Band) Switch is necessary when one or more modems within the redundancy
system connect to the other polarization of the antenna or to multiple antennas.

The CRS-280/280L is designed for use with the f ollowing C omtech EF Data products:

Table 1-1. IF Switch Compatibility Table

Modem Remarks Max 1:N Redundancy

CDM-570L/570AL Used with CRS-300 or CRS-500 1:10
CDM-600L
CLM-9600L
CDM-600/600L

Used with CRS-300 or CRS-500 w/CRS-350 (ESC only) 1:10

CDM-710
CDM-710G/710GL

SLM-5650/5650A
SDM-300L3** Used with SMS-7000** 1:8
SDM-2020D**

(L-Band)

Used with CRS-400 (HSSI)** 1:10

** Indicates a Comtech EF Data legacy product that is no longer in production

The CRS-280 replaces the following Comtech EF Data active or legacy products:

• CRS-282 IF switch for 70/140 MHz applications

The CRS-280L replaces the following Comtech EF Data active or legacy products:

• IFU for SMS-7000 L-B and app licat ions .

• CRS-282 IF switch for L-Band applications (CRS 300/CRS 500)

Introduction 1–2 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

The CRS-280L features redundant power supplies with status Light Emitting Diodes (LEDs) on
the front panel. It may be configured for 4 to 10 channel applications (SMS-7000 supports 8
channels max). Each channel has a transmit section with TX input / uplink output and a receive
section with Rx output / downlink input.

Figure 1-3 shows the system level block diagram for a CRS-280L system.

Figure 1-3. 1:10 Redundancy w/CRS-280L – System-level Block Diagram

1.1.1 Compatibility

The Comtech EF Data CRS-280/280L IF Switch is designed specifically as an accessory
product for Comtech EF Data equipment. It is not designed to operate with any other
manufacturer's equipment.

The CRS-280L is not designed to convey Direct Current (DC) power to external equipment
such as LNBs or BUCs. Do not apply DC power to the L-Band input and output (Type ‘N’)
ports of the switch. In addition, the CRS-280L is not designed to pass to 10 MHz reference

or FSK signaling.

Introduction 1–3 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy

1:4 Configuration

1:10 Configuration

Status

Revision -

1.2 Physical Description

The CRS-280 is cons tructed as a 4RU -high, rack-mounting chassis t hat can be freestanding, if
desired. Rack handles are not supplied.

The CRS-280L is constructed as a 4RU -high, rack-mounting chassis t hat can be freestanding,
if desired. It is provided with rack handles at the f r ont for easy rem oval fr om and placement into
a rack.

1.2.1 Front Panel

Figure 1-4. CRS-280 Front Panel

LEDs

Figure 1-5. CRS-280L Front Panel (1:10 Configuration shown)

Introduction 1–4 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy

Power Supply

Ground

Power Supply

Control

Control

Interface

Revision -

1.2.2 Rear Panel

Figure 1-6. CRS-280 Rear Panel

Interfaces

Figure 1-7. CRS-280L Rear Panel

Introduction 1–5 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

1.2.3 Dimensional Envelope

Figure 1-8. CRS-280 (70/140 MHz) IF Switch Dimensional Envelope

Introduction 1–6 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy

17.00

(43.18)

13.18

(33.48)

13.92

(35.36)

6.96

(17.68)

19.00

(48.26)

Revision -

Figure 1-9. CRS-280L (L-Band) IF Switch Dimensional Envelope

Introduction 1–7 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy

TX Return Loss

18 dB return loss into 75Ω

TX to TX Channel Isolation

RX to RX Channel Isolation

> 50 dB

> 70 dB

TX to RX Channel Isolation

> 60 dB

> 90 dB

Tx IF Loss / Flatness

< 2.5 dB / 1.0 dB over operating

Revision -

1.3 Summary of Specifications

Equipment Type

Comtech EF Data Modems Supported

CRS-280

(70/140 MHz)

• SDM-2020D (L-Band) (when used
with CRS-400) (legacy products)

• SDM-300L3 (when used with SMS-

7000) (legacy products)

• CDM-570L (when used with CRS-
300 or CRS-500)

• CDM-600L (when used with CRS-

300)

• CDM-9600L (when used with CRS-

300)

• CDM-625/625A (when used with
CRS-300 or CRS-500)

• SLM-5650A (when used with CRS-
300 or CRS-500)

• SDM-2020D (L-Band) (when used
with CRS-400) (legacy products)

• SDM-300L3 (when used with SMS-

7000) (legacy products)

• CDM-570L (when used with CRS-
300 or CRS-500)

• CDM-600L (when used with CRS-

300)

• CDM-9600L (when used with CRS-

300)

• CDM-625/625A (when used with
CRS-300 or CRS-500)

• SLM-5650A (when used with CRS-
300 or CRS-500)

CRS-280L

(L-Band)

Tx/Rx Operating Frequency 50 to 180 MHz 950 to 2150 MHz

IF Impedance

50Ω and 75Ω 50Ω

< 12 dB return loss into 50Ω

(50Ω optional)
> 50 dB > 70 dB

TX (in) to associated Uplink (out) < 1.5 dB over operating frequency

BU (in) to any Uplink (out)

< 1.5 dB over operating frequency

< 0.8 dB / 0.5 dB over operating
frequency

frequency

Rx IF Loss / Flatness

DL (in) to associated RX (out) < 5 dB over operating frequency

Any DL (in) to BU RX (out) < 5 dB over operating frequency

< 4.0 dB / 0.5 dB over operating
frequency

< 5.5 dB / 1.0 dB over operating
frequency

Max. # of Downlinks 10 10

Tx/Rx IF Connectors

50/75Ω BNC female 50Ω Type ‘N’ female

Introduction 1–8 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy

25-pin sub-D female, compatible with

Received from an external power

Redundant 25 W, AC, Universal Input

0.75 A rms max. @ 90 VAC

All uplinks/downlinks revert to

19” (48.26 cm) wide x 2.5” (6.35 cm)

19” (48.26 cm) wide x 14” (35.56 cm)

Revision -

Equipment Type

Control Interface

Input Power

Power Loss Failsafe

Environmental

Operating Temperature

Storage Temperature

CRS-280

(70/140 MHz)

• 25-pin sub-D female, compatible

CRS-300 controller

with CRS-300 controller

• 15-pin sub-D female, compatible
with SMS-7000

source, such as a modem chassis

Switch Mode Power Supplies

Input voltage N/A 90 - 264 VAC

Input frequency N/A 47 - 440 Hz

Input current N/A

N/A

0.35 A rms @ 230 VAC

associated L-Band inputs/outputs

32 to +122°F (0 to +50°C) 32 to +122°F (0 to +50°C)

-58 to +212°F (-50 to +100°C) -58 to +212°F (-50 to +100°C)

CRS-280L

(L-Band)

Dimensions

Humidity

95% at +122°F (+50°C), Non­condensing

deep x 7” (17.78 cm) high

95% at +122°F (+50°C), Non­condensing

deep x 7” (17.78 cm) high

Weight < 10 lbs (< 4.54 kg) < 25 lbs (<11.35 kg)

EMC and Safety

• ‘CE’ as follows:

o EN 55022-1997 Class A

(Emissions)

o EN-55024-1998

(EMC/Immunity)

o EN 50082-1 (Immunity)
o EN 60950 (Safety)

•

FCC Part 15 Class A

• ‘CE’ as follows:

o EN 55022-1997 Class A

(Emissions)

o EN-55024-1998

(EMC/Immunity)

o EN 50082-1 (Immunity)
o EN 60950 (Safety)

•

FCC Part 15 Class A

Introduction 1–9 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

1.3.1 CRS-280L Typical Insertion Loss Graphs

Figure 1-10. Graph 1 – Downlink Input to Rx Output

Introduction 1–10 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Figure 1-11. Graph 2 – Downlink Input to Backup Rx Output

Introduction 1–11 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Figure 1-12. Graph 3 – Backup Input to Selected Uplink Output

Introduction 1–12 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Figure 1-13. Graph 4 – Tx Input to Associated Uplink Output

Introduction 1–13 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Notes:

Introduction 1–14 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy

Step

Procedure

1

Inspect shipping containers for damage.

If shipping containers are damaged, keep them until the contents of the shipment have been carefully

3

Remove the packing list from the outside of the shipping carton.

4

Open the carton and remove the contents.

5

Check the contents against the packing list to verify completeness of the shipment.

If damage is evident, contact the carrier and Comtech EF Data immediately and submit a damage

7

If the unit needs to be returned to Comtech EF Data, use the original shipping container.

Revision -

Chapter 2. INSTALLATION

2.1 Unpacking and Inspection

Do not use any cutting tool that will extend more than 1” into the containter and
cause damage to the unit.

Be sure to keep all shipping materials for the carrier’s inspection.

The CRS-280/280L IF Switch for 1:N Redundancy is packaged and shipped in a pre-formed,
reusable cardboard carton containing foam spacing for maximum shipping protection. The
Installation and Operation manual can be found on Comtech EF Data’s website

www.comtechefdata.com

Unpack and inspect the CRS-280/280L as follows:

2

6

inspected and checked for normal operation.

report.

under the Download Manuals tab, under Modem Accessories Manuals.

Installation 2–1 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

2.2 Mounting

Under no circumstance should the highest internal rack temperature be
allowed to exceed 50°C (122°F)..

The CRS-280/280L CANNOT have rack slides mounted to the side of the
chassis. Comtech EF Data recommends that an alternate method of support,
such as rack shelves, is employed within the rack if front-mounting the unit
is not feasible. If there is any doubt, ple ase consult the Comtech EF Data
Customer Support department.

The CRS-280 replaces the CRS-282 (used with the Comtech EF Data’s CRS-300 1:10
Redundancy Switch, CRS-500 M:N Redundancy System, or CEFD legacy product CRS-400) and
IFU (CEFD legacy product SMS-7000) for 70/140 MHz applications.

The CRS-280L replaces the CRS-282 (used with the Comtech EF Data’s CRS-300 1:10
Redundancy Switch, CRS-500 M:N Redundancy System, or CEFD legacy product CRS-400) and
IFU (CEFD legacy product SMS-7000) for L-Band applications.

The CRS-280L is constructed as a 4RU-high, rack-mounting chassis. Rack handles at the front of
the unit facilitate removal from and placement into a rack. It is compatible with mounting at the top,
back, or front of the rack (refer to the associated controller documentation for additional details).

To Install the CRS-280/280L:

Mount the switch with user-furnished hardware, using the unit’s front panel mounting holes only.
Since the switch itself is relatively passive, no additional clearance is needed between it and the
nearest Modem.

Typically, the CRS-280/280L is mounted in a rack along with the modems with which it operates;
therefore, it is important to ensure that there is adequate clearance for ventilation, particularly at the
sides. In rack systems where there is high heat dissipation, forced air cooling must be provided by
top or bottom mounted fans or blowers.

Installation 2–2 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Chapter 3. CONNECTOR

PINOUTS

3.1 Connector Overview

Chapter 4. CABLES

See Chapter 4. CABLES
CRS-280/280L and its companion redundant switches, redundant and traffic modems, and uplink
and downlink equipment.

AND CONNECTIONS

AND CONNECTIONS for complete details on IF cabling between the

Connector Pinouts 3–1 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

3.1.1 CRS-280 Connector Overview

Front Panel View

Rear Panel View

Figure 3-1. CRS-280 Connectors

The front and rear panels of the CRS-280 IF Switch are shown in Figure 3-1.
The front panel connectors provide all necessary connections to connect all equipment internal

and external to the 1:N redundancy setup. The rear panel connector of the CRS-280 provides the
control connector between the CRS-280 and its companion redundancy switch (e.g., CRS-300,
CRS-500, etc.).

Connector Pinouts 3–2 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy

Front

IF

Test Point

Tx from
Up Converter

Tx from Traffic

Down

Rear Panel

Control Interface

J1

** Indicates a Comtech EF Data legacy product that is no longer in production.

Revision -

Table 3-1 summarizes the connectors, grouped according to location (front, rear, or data
interface) and service function.

Table 3-1. CRS-280 External Connectors (Front and Rear Panel)

Connector Group Name Connector Type Function

Panel

Tx Backup

Redundant

(Transmit IF) BNC female

70/140
Input

Modem

Tx Traffic 1­10

Modem
Rx to

Rx Backup

Redundant
Modem

(Receive IF) BNC female

70/140
Output

Rx Traffic 1­10

Converter
Rx to Traffic

Modem

CRS Control
Interface

25-pin Type ‘D’ female

Control interface for CRS-400**, CRS-300,
CRS-500 Redundancy Switching products

The European EMC Directive (EN55022, EN50082-1) requires using properly shielded cables for DATA
I/O. These cables must be double-shielded from end-to-end, ensuring a continuous ground shield.

Connector Pinouts 3–3 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

3.1.2 CRS-280L Connector Overview

Front Panel View

Rear Panel View (Standard AC Unit shown)

Figure 3-2. CRS-280L Connectors

The front and rear panels of the CRS-280L L-B and IF S witch are shown in Figure 3-2.
The front panel connectors provide all necessary connections to connect all equipment internal

and external to the 1:N redundancy setup. The rear panel connectors of the CRS-280L provide
the control connectors between the CRS-280L and its companion redundancy switch (e.g., CRS­300, CRS-500, etc.).

Connector Pinouts 3–4 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy

Front

IF

Test Out

Tx In

Up Link Out

Tx In

Rear Panel

Control

J1
J2 SMS Control

Control interface for SMS-7000**

p/o Optional Primary and Backup DC
Ground

#10-32 stud

Common Chassis Ground

Revision -

Table 3-2 summarizes the connectors, grouped according to location (front, rear, or data
interface) and service function.

Table 3-2. CRS-280L External Connectors (Front and Rear Panel)

Connector Group Name Connector Type Function

Panel

Interface

Power / Ground

(Transmit IF)

(Receive IF)

CRS Control

22X Type ‘N’ 50Ω

female

22X Type ‘N’ 50Ω

female

25-pin Type ‘D’ female

Interface

Interface

15-pin Type ‘D’ male

AC Input 2X IEC

DC Input

2X 3-screw Terminal
Block

Tx Backup

L-Band
Input

Tx Traffic 1­10

Test In

Rx Backup

L-Band
Output

Rx Traffic 1­10

Rx Out
Down Link In
Rx out

Control interface for CRS-400**, CRS-300,
CRS-500 Redundancy Switching products

Redudancy Switching Product
p/o Primary and Backup AC Power Supply

Modules (CEFD P/N PL/10207-1)

Power Supply Modules (CEFD P/N PL-

0000355)

** Indicates a Comtech EF Data legacy product that is no longer in production.

The European EMC Directive (EN55022, EN50082-1) requires using properly shielded cables for DATA
I/O. These cables must be double-shielded from end-to-end, ensuring a continuous ground shield.

Connector Pinouts 3–5 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

3.2 Front Panel Connectors

Unless otherwise noted, the connectors featured on the front panel of the CRS-280/280L are
intended for connection to all IF equipment internal and external to the 1:N redundancy setup.

3.3 Rear Panel Control Connectors

Unless otherwise noted, the connectors featured on the rear panel of the CRS-280/280L are
intended for connection to the companion redundancy switch control interface.

3.3.1 CRS-280 Switch Control Interface Connector

3.3.1.1 J1 CRS Control Interface Connector, DB-25F

The 25-pin ‘D’ Type female (DB-25F) J1 CRS Control Interface
connector is used to connect the CRS-280L to the IF Switch Control
port, located on the CRS-230 Controller card installed in the CRS-400

1:8 Redundancy Switch or CRS-300 1:10 Redundancy Switch, or to the
P1 IF Switch Control port located on the control interface side of the CRS-500 M:N Redundancy
System’s Data Switch Unit (DSU).

The Comtech EF Data CRS-400 1:8 Redundancy Switch is a legacy product that is
no longer in production.

The J1 CRS Control Interface connector communicates with the logic interface of the
companion redundancy switch to drive the currently selected terrestrial modem, and to decide
whether the system is in bridged or backup mode. The CRS-280L performs the same bridging
and backing up functions of the Tx and Rx IF signals to match what the companion redundant
switch does to the terrestrial data signals.

Connector Pinouts 3–6 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

3.3.2 CRS-280L Switch Control Interface Connectors

3.3.2.1 J1 CRS Control Interface Connector, DB-25F

The 25-pin ‘D’ Type female (DB-25F) J1 CRS Control Interface

connector is used to connect the CRS-280L to the IF Switch Control

port, located on the CRS-230 Controller card installed in the CRS-400

1:8 Redundancy Switch or CRS-300 1:10 Redundancy Switch, or to the
P1 IF Switch Control port located on the control interface side of the CRS-500 M:N Redundancy
System’s Data Switch Unit (DSU).

The Comtech EF Data CRS-400 1:8 Redundancy Switch is a legacy product that is
no longer in production.

The J1 CRS Control Interface connector communicates with the logic interface of the
companion redundancy switch to drive the currently selected terrestrial modem, and to decide
whether the system is in bridged or backup mode. The CRS-280L performs the same bridging
and backing up functions of the Tx and Rx IF signals to match what the companion redundant
switch does to the terrestrial data signals.

3.3.2.2 J2 SMS Control Interface Connector, DB-15M

The 15-pin ‘D’ Type male (DB-15M) J2 SMS Control Interface

connector is used to connect the CRS-280L to the J12 IF Control
Interface port of SMS-7000 1:8 Modem Protection Switch’s Data
Switch Unit (DSU).

The Comtech EF Data SMS-7000 1:8 Modem Protection Switch is a legacy
product that is no longer in production.

Connector Pinouts 3–7 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy

Standard AC Power Specifications

Input Power

25W typical

Input Voltage
Connector Type

IEC

Fuse Protection

1.0A Slow-blow (115 volt AC operation)

Connector Type

Terminal Block

Fuse Protection

6.25A Slow-blow

Revision -

3.3.2.3 Power / Ground Connections

For continued operator safety, always replace fuses with the correct type and
rating.

3.3.2.3.1 Alternating Current (AC) Power Connectors

Two AC power supplies – one primary, one backup – are provided. For each, a
standard, detachable, non-locking 3-prong power cord (IEC plug) supplies the
Alternating Current (AC) power to the CRS-280L. Observe the following:

100 - 240 volts AC, +6%/-10% - autosensing
(total absolute max. range is 90-264 volts AC)

2.0A Slow-blow (230 volt AC operation)
Line and neutral fusing
20 mm type fuses

3.3.2.3.2 Direct Current (DC) Power Connectors (optional)

Two DC power supplies – one primary, one backup – are optionally
available. For each, a standard, 3-screw terminal block with fuse
holder supplies the Direct Current (DC) power to the CRS-280L.
Observe the following:

Input Power 25W maximum
Input Voltage 36 to 72 VDC; 6.25 amps

Optional DC Power Specifications

Connector Pinouts 3–8 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

3.3.2.4 Ground Connector

The AC power connector provides the safety ground.

A #10-32 stud, located to the lower left hand side of the CRS-280L rear panel, is
provided for connecting a common chassis ground among equipment.

Connector Pinouts 3–9 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

BLANK PAGE

Connector Pinouts 3–10 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy
Revision -

Chapter 4. CABLES AND

CONNECTIONS

4.1 Overview

Chapter 2. INSTALLATION
Appendix A. CABLE DRAWINGS

When assembling a Comtech EF Data 1:N Redundancy System, in addition to purchasing the
desired modem group (one Redundant modem, up to 10 Traffic modems) and the appropriate
companion switch (i.e., CRS-300, CRS-500 etc.), the user is also required to purchase all cables
and components required for int e r connection of the redundant configuration to various interfaces
(i.e., control, IF, and data).

Once the CRS-280/280L switch, its companion redundancy switch, and all modems have been
mounted as outlined in Chapter 2. INSTALLATION, the user must properly attach all required
cabling, then configure the system for correct operation.

For the purpose of clarity, this chapter deals only with the connections needed for the
CRS-280/280L’s application within a configured 1:N Redundancy System. Refer to the applicable
companion switch Installation and Operation Manual for pertinent data interface cabling and other
cable connection information.

The sections that follow in this chapter provide specific interface examples that identify the
individual re du ndan cy cabl e( s) required to interconnect the two interfaces. For line drawings of the
cables specified in this chapter, see Appendix A. CABLE DRAWINGS.

Leave the switch and all modems powered off until all connections are ready.

Cables and Connections 4–1 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy
Revision -

4.2 Control Cable Connections

Each CRS-280/280L is supplied with a control cable for connection to the associated 1:N
Redundancy Switch control unit. The control cable must be specified at time of order:

1: N Redundancy Switch CEFD Part No. Description

SMS-7000** CA/5343-1 Control Cable, DB-15F  DB-15M, 8’
CRS-400**

CA/WR0066 Control Cable, DB-25M  DB-25F, 6’

CRS-300
CRS-500 CA-0021666 Control Cable, DB-9F  DB-25M, 8’
** Indicates a Comtech EF Data legacy product that is no longer in production.

1. When connecting the Control cable between the CRS-280L and the
redundancy switch, ensure that screw locks on the ‘D’ type connectors are
securely fastened. This will prevent the accidental unmating of the cable,
particularly when a standby unit is being removed or replaced.

2. Only one control interface must be used. Do not make connections to both
control interfaces on the CRS-280L. The CRS-280L automatically detects
the control interface in use and cannot function with both control cables
connected.

Connect the supplied cable between the Redundancy Switch (controller) and the CRS-280/280L
(refer to the pertinent Redundancy Switch Installation and Operation Manual for additional
information):

For CRS-280/280L  Refer to:
SMS-7000 1:8 Modem Protection Switch** Sect. 4.2.1
CRS-400 1:8 HSSI Redundancy Switch** Sect. 4.2.2
CRS-300 1:N Redundancy Switch Sect. 4.2.3
CRS-500 M:N Redunancy System Sect. 4.2.4

Cables and Connections 4–2 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy

Step

Instructions

1

Connect the DB-15F connector on the CA/5343-1 Control Cable to the DB-15M J2 SMS Control Interface

2

Connect the DB-15M connector on the CA/5343-1 Control Cable to the DB-15F J12 IF Control Interface

3

Step

Instructions

IF Switch Control

3

Step

Instructions

1

CA/WR0066

J1 CRS Control

2

Connect the other end of the control cable to the DB-25M IF Switch Control port on the CRS-230

3

Secure the cable by tightening the screw locks on both ends of the control cable.

Revision -

4.2.1 SMS-7000 1:8 Modem Protection Switch Control Cable Connection

The Comtech EF Data SMS-7000 1:8 Modem Protection Switch is a legacy
product that is no longer in production.

As shown in Figure 4-1:

port on the rear panel of the CRS-280L.

port on the Control/Modem side of the SMS-7000 Data Switch Unit (DSU).
Note: The CRS-280L serves to replace, in its entirety, the SMS-7000 IF Switch Unit (IFU).

Secure the cable by tightening the screw locks on both ends of the control cable.

4.2.2 CRS-400 1:8 Redundancy Switch Control Cable Connection

The Comtech EF Data CRS-400 1:8 Redundancy Switch is a legacy product that
is no longer in production.

As shown in Figure 4-2:

Connect the DB-25M connector of the CA/WR0066 control cable to the DB-25F J1 CRS Control

1

Interface port on the rear panel of the CRS-280L.

Connect the other end of the control cable to the DB-25M

2

Controller card, installed in the rear panel of the CRS-400 1:8 Redundancy Switch.
Secure the cable by tightening the screw locks on both ends of the control cable.

port on the CRS-230

4.2.3 CRS-300 1:N Redundancy Switch Control Cable Connection

As shown in Figure 4-3 and Figure 4-4:

Connect the DB-25M connector of the
Interface port on the rear panel of the CRS-280/280L.

Controller card, installed in the rear panel of the CRS-300 1:N Redundancy Switch.

control cable to the DB-25F

Cables and Connections 4–3 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy

Step

Instructions

CA-0021666

P1 IF Switch

3

Revision -

4.2.4 CRS-500 M:N Redundancy System Control Cable Connection

As shown in Figure 4-5 and Figure 4-6:

Connect the DB-25M connector of the CA-0021666 Control Cable to the DB-25F J1 CRS Control

1

Interface port on the rear panel of the CRS-280/280L.

Connect the final DB-9F connector on the

2

Control Cable to the DB-9M
Control port on the control interface side of the CRS-500 M:N Redundancy System’s Data Switch Unit
(DSU).

Note: The CRS-500 DSU is, in turn, connected to the CRS-500 Control Switch Unit (CSU) via the CA­0000234 Control Cable – see the CRS-500 M:N Redundancy System Installation and Operation
Manual for complete details.

Secure the cable by tightening the screw locks on both ends of the control cable.

Cables and Connections 4–4 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy
Revision -

Figure 4-1. SMS-7000 to CRS-280L Control Cable Connection

The Comtech EF Data SMS-7000 1:8 Modem Protection Switch is a legacy product
that is no longer in production.

Cables and Connections 4–5 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy
Revision -

Figure 4-2. CRS-400 to CRS-280L Control Cable Connection

The Comtech EF Data CRS-400 1:8 Redundancy Switch is a legacy product that is no
longer in production.

Cables and Connections 4–6 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy
Revision -

Figure 4-3. CRS-300 to CRS-280 Control Cable Connection

Cables and Connections 4–7 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy
Revision -

Figure 4-4. CRS-300 to CRS-280L Control Cable Connection

Cables and Connections 4–8 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy
Revision -

Figure 4-5. CRS-500 to CRS-280 Control Cable Connection

Cables and Connections 4–9 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy
Revision -

Figure 4-6. CRS-500 to CRS-280L Control Cable Connection

Cables and Connections 4–10 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy

Frequency, Impedance

Connector Type

CEFD Cable

BNC female

PL/0946-2

BNC female

PL/0813-8

CEFD Part No.

Description

Revision -

4.3 Cable Connections

4.3.1 CRS-280 IF Cable Connections

70/140 MHZ, 50Ω
70/140 MHZ, 70Ω

4.3.2 CRS-280L L-Band IF Cable Connections

Cables for connecting the CRS-280L L-Band IF Switch to the L-Band modems within the
redundancy system are available for purchase from Comtech EF Data and can be ordered at the
same time the order is placed for the CRS-280L:

CA/RF10453-2
CA/RF10453-4
CA/RF10453-6
CA/RF10453-8

Cable Assembly, L-Band 50Ω, Type ‘N’ male to Type ‘N’ male connectors, 2’
Cable Assembly, L-Band 50Ω, Type ‘N’ male to Type ‘N’ male connectors, 4’
Cable Assembly, L-Band 50Ω, Type ‘N’ male to Type ‘N’ male connectors, 6’
Cable Assembly, L-Band 50Ω, Type ‘N’ male to Type ‘N’ male connectors, 8’

4.3.3 L-Band IF Cable Characteristics

If L-Band cables are not purchased from Comtech EF Data, use of a
suitable equivalent is recommended.

Cable Type Loss at 1 GHz Loss at 2 GHz

Semflex BPE200 (or equivalent) 0.11 dB/ft 0.15 dB/ft

4.3.4 L-Band Switch-to-Modem Cabling Requirements

The number of cables required depends on the switch system configuration. Per the
example shown at right, each modem connected to the CRS-280L front panel
requires two L-Band cables:

• One cable for the Rx L-Band connection

• One cable for the Tx L-Band connecti on

Each cable must be connected and secured using the Type ‘N’ threaded female
connectors on the front panel of the CRS-280L and rear panel of the L-Band
modems.

Cables and Connections 4–11 MN-CRS-280/280L

CRS-280/280-L IF Switch for 1:N Redundancy

RX 2 (RX Out)

Revision -

Cable connections are defined as follows:

L-Band Modem Connection CRS-280L Connection Comments

Redundant Modem

Prime Modem #1

Prime Modem #2

Prime Modem #3

Prime Modem #4

Prime Modem #5

Prime Modem #6

Prime Modem #7

TX Output ↔
RX Input ↔
TX Output ↔
RX Input ↔
TX Output ↔
RX Input ↔
TX Output ↔
RX Input ↔
TX Output ↔
RX Input ↔
TX Output ↔
RX Input ↔
TX Output ↔
RX Input ↔
TX Output ↔
RX Input ↔

TX Backup (TX In)
RX Backup (RX Out)
TX 1 (TX In)
RX 1 (RX Out)
TX 2 (TX In)

TX 3 (TX In)
RX 3 (RX Out)
TX 4 (TX In)
RX 4 (RX Out)
TX 5 (TX In)
RX 5 (RX Out)
TX 6 (TX In)
RX 6 (RX Out)
TX 7 (TX In)
RX 7 (RX Out)

TX Output ↔

TX 8 (TX In)

Prime Modem #8

RX Input ↔
TX Output ↔

RX 8 (RX Out)
TX 9 (TX In)

Prime Modem #9

RX Input ↔
TX Output ↔

RX 9 (RX Out)
TX 10 (TX In)

Prime Modem #10

RX Input ↔

RX 10 (RX Out)

4.3.5 L-Band Uplink/Downlink Cable Connections

The CRS-280L is not designed to convey DCpower to external equipment such as
LNBs or BUCs. Do not apply DC power to the L-Band input and output (Type ‘N’)
ports of the switch.

CEFD recommends that connections to uplink and downlink equipment be made after all other
system cabling and configuration is complete. Cabling to and from the CRS-280L uplink and
downlink ports is dependant on the system configuration and the uplink/downlink equipment used.
For additional information, refer to the uplink/downlink equipment documentation.

Cables and Connections 4–12 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Chapter 5. REDUNDANCY SYSTEM

CONFIGURATION / OPERATION

5.1 Overview

In order to avoid damage to the modems, the companion redundant switch, and
the CRS-280L L-Band IF Switch, and it is important for the user to follow this
sequence of configuration:

First,

•

redundancy switch, and CRS-280L as outlined previously in Chapter 4.
CABLES AND CONNECTIONS.

connect cables between the (powered OFF) modems, companion

Second,

•

the respective modem and companion switch Installation and Operation
Manuals.

Third,

•

operations, the user should follow the instructions in the next two chapter
sections in the sequence they are presented.

configure the modems for 1:N redundant operation, as outlined in

once the modems have been properly configured for 1:N redundant

5.2 CRS-280L Input Power Cord Connections

Do not turn the CRS-280L power supply switches to the on position until all
system connections are in place.

Connect the AC power cords as follows:

Step Instructions

1

2 Each CRS-280L is supplied with two power cords – one for each power supply power input.

Ensure that both power supply switches are in the off position before connecting the power supply
power cords.

Connect the female end of each supplied power cords to its mating socket.

3 Plug both power cords into the AC power source.

Redundancy System Configuration / Operation 5–1 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

5.3 CRS-280L 1:N Redundancy System Power-up Sequence

After the 1:N redundant system cabling is complete, and the companion switch and modems
have been initially configured, the complete sysyem may be powered up. The typical equipment
power-up sequence is as follows:

Step Instructions

1 Turn on the redundant and traffic L-Band modems.
2 Power up the CRS-280L L-Band IF Switch switch by turning both power supply switches, located on

the CRS-280L rear panel, to the on position.
Once the power supplies are turned on, both power status LEDs (A and B) on the front panel should

illuminate green.

3 Power up the companion switch as applicable (e.g., turn on the system controller / data switch for the

CRS-300, CRS-400, or SMS-7000; turn on the CRS-500 Control Switch Unit (CSU), etc.)

The CRS-280L is designed to operate with only one power supply energized. However, it is
recommended to continually operate the system with both supplies energized for redundancy.

5.3.1 CRS-280L Operations with the CRS-500 M:N Redundancy System

While the CRS-500 M:N Redundancy System supports 2:N redundancy and IP Sub-MUX
operation, the CRS-280L L-Band IF Switch is limited to 1:10 (maximum) redundancy – 2:N
redundancy and IP Sub-MUX operation are not su pported by the CRS-280L.

Redundancy System Configuration / Operation 5–2 MN-CRS-280/280L

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix A A-1 MN-CRS-280/280L

Appendix A. CABLE DRAWINGS

A.1 Introduction

This appendix contains drawings of cables used with the CRS-280 (70/140 MH z) and the CRS-280L (L-Band) IF Switch for 1:N
Redundancy. These cables are broken into two categories – Control Interface Cables and IF Interface Cables:

• The Control Interf ace Cables are used to connect the CRS-280L r ear panel J1 CRS Control Interf ace or J2 SMS Control
Interface connector to its companion redundancy switch IF Switch Control Interface connector.

• The IF Interface Cables may be selected and used to connect the CRS-280L, via the front panel Tx/Rx Type ‘N’
threaded female connectors, to the Redundant Modem and up to 10 traf fic modems t hat are part of the 1: N redundancy
setup, as well as to any external uplink / downlink RF equipment.

Each section provides illustrations of the cables’ technical specifications; additionally, the table in each section cross-reference
to the illustrations found in

Chapter 4. CABLES AND CONNECTIONS.

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix A A-2 MN-CRS-280/280L

A.2 Control Interface Cables

App. A FIG REF Ch. 4 FIG CEFD Cable P/N Description Used For…

A-1 4-1 CA/5343-1 Control Cable, DB-15F  DB-15M, 8’ CRS-280L  SMS-7000 Data Switch Unit (DSU)

A-2 4-2, 4-3 CA/WR0066 Control/Data Cable, DB-25F  DB-25M, 6’ CRS-280L  CRS-400/CRS-300

A-3 4-4 CA-0021666 Control Cable, DB-25M  DB-9F, 8’ CRS-280/280L  CRS-500 Data Switch Unit (DSU)

The Comtech EF Data SMS-7000 1:8 Modem Protection Switch and CRS-400 1:8 Redundancy Switch are legacy
products that are no longer in production.

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix A A-3 MN-CRS-280/280L

A.2.1 SMS-7000 Control Cable

The Comtech EF Data SMS-7000 1:8 Modem Protection Switch is a legacy product that is no longer in production.

Figure A-1. CRS-280L  SMS-7000 Data Switch Unit (DSU) Control Cable (CEFD P/N CA/5343-1)

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix A A-4 MN-CRS-280/280L

A.2.2 CRS-400/CRS-300 Control Cable

The Comtech EF Data CRS-400 1:8 Redundancy Switch is a legacy product that is no longer in production.

Figure A-2. CRS-280L  CRS-400, CRS-300 Control Cable (CEFD P/N CA/WR0066)

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix A A-5 MN-CRS-280/280L

A.2.3 CRS-500 Control Cable

Figure A-3. CRS-280/280L  CRS-500 Data Switch Unit (DSU) Control Cable (CEFD P/N CA-0021666)

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix A A-6 MN-CRS-280/280L

A.3 IF Interface Cable, Type ‘N’ 50Ω

Figure A-4. Type ‘N’ 50Ω IF Coax Cable (CEFD P/N CA/RF10453-x)

CEFD P/N

DIM ‘A’

CA/RF10453-2

24.00 ± .80

CA/RF10453-4

48.00 ± 1.50

CA/RF10453-6

72.00 ± 3.00

CA/RF10453-8

96.00 ± 3.00

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix B B–1 MN-CRS-280/280L

Appendix B. CRS-280L POWER SUPPLY

MODULE REPLACEMENT

B.1 Introduction

The CRS-280L L-Band IF Switch for 1:N Redundancy features dual power supply modules: the standard AC module (CEFD P/N Pl/10207-1), or
the optional DC module (CEFD P/N PL 0000355). These modules are the only field replaceable components in the CRS-280L.

This appendix illustrates the procedure required to remove and install a CRS-280L power supply module (Figure B 1) into any CRS 280L L-Band
IF Switch unit.

Unless otherwise noted, while the illustrations throughout this appendix visually depict the replacement of a standard PL/10207-1 AC Power
Supply Module, this procedure is typical for removing and installing either a standard AC or optional DC power supply module into the applicable
A or B compartment in the rear of the CRS 280L chassis.

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix B B–2 MN-CRS-280/280L

Power Supply

Power Supply

Figure B-1. CRS-280L Rear Panel (shown with PL/10207-1 AC Modules)

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix B B–3 MN-CRS-280/280L

B.2 Power Supply Module Removal Procedure

Step Task

1

DISCONNECT THE CRS-280L FROM

ITS POWER SOURCE!

For AC Units (pictured): Shut off the AC power

switch on both power supply modules and
disconnect both power cords from their
receptacles.

For DC Units: Make sure to disconnect both
power cords from their DC power sources, then
unscrew the positive, negative, and ground leads
from the terminal block of the module being
replaced.

2

Loosen the four captive mounting screws of the
module to be replaced, then carefully pull the
module plate away from the unit.

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix B B–4 MN-CRS-280/280L

Step Task

3 Carefully remove the Power Supply Cable from

its mating connector on the old power supply
module PCB, then set the old power supply
module aside.

Power Supply
Cable

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix B B–5 MN-CRS-280/280L

B.3 Power Supply Module Installation Procedure

Step Task

1 Identify for assembly the Power Supply

Cable (connected to the CRS-280L
chassis PCB), and its mating
connector on the new power supply
module PCB.

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix B B–6 MN-CRS-280/280L

Step Task

2 Carefully reconnect the Power Supply

Cable to its mating connector on the
new power supply module PCB.

3 Assemble the power supply module

plate to the CRS-280L chassis, taking
care not to crimp the Power Supply
Cable when doing so, then tighten the
four captive mounting screws of the
module to secure the module in place.

Power Supply
Cable

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix B B–7 MN-CRS-280/280L

Step Task

4

For AC Units (pictured): Reconnect

the power cords for both power supply
modules. The AC power may be
switched on to both power supply
modules once all control and IF
cabling connections have been
confirmed.

For DC Units: Screw on the positive,
negative, and ground leads to the
terminal block of the replacement
power supply module. The unit may be
reconnected to both DC power
sources once all control and IF cabling
connections have been confirmed.

The module installation has been completed and the CRS-280L L-Band Switch for 1:N Redundancy is ready for operation.

CRS-280/280L IF Switch for 1:N Redundancy
Revision -

Appendix B B–8 MN-CRS-280/280L

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