CRS-500 1:N Redundancy System
Revision 4
Cables and Connections
5–29
MN-CRS-500
5.4
IF Cable Connections
5.4.1
IF Cabling Overview
For hub applications, there are two basic IF configurations –
single transponder
or
multiple
transponders
.
For a single transponder configuration
, connect all modems to the same Up/Down Converter.
This configuration eliminates the need for an IF Switch Unit (ISU) because the CRS-500 mutes
(shuts off) the offline modem’s Tx IF carrier.
For a multiple transponder configuration
, you may group and connect the modems in various
combinations to multiple transponders. This configuration requires the use of ISU.
For either configuration, once all CRS-500 1:N Redundancy System connections have been
made and proper system operation has been verified, you should then connect the user-provided
Up and Down Converters.
To prevent unintended signals from reaching the satellite, do not
connect the IF to any Up Converters until the CRS-500 1:N Redundancy
System is fully cabled and configured.
5.4.2
IF Cable Connections – Single Transponder (No ISU)
To prevent problems resulting from impedance mismatch, ensure that the
impedance for the modem’s cables and combiner are the same.
Figure 5-12 shows an example of a single transponder IF configuration (L-Band operation is
depicted in this example). Connect the user-provided IF cables. Do these steps:
1.
Make your Transmit (Tx) IF Connections:
a.
Connect the appropriate user-provided IF cables from each modem’s “Tx IF”
connector (BNC for 70/140 MHz, Type ‘N’ for L-Band) to a single user-provided
power combiner.
b.
Connect the output of the power combiner to the user-provided Up converter.
2.
Make your Receive (Rx) IF Connections:
a.
Connect the appropriate user-provided cables from each modem’s “Rx IF”
connector (BNC for 70/140 MHz, Type ‘N’ for L-Band) to the output ports of a
single user-provided signal splitter.
b.
Connect the input of the signal splitter to the output of the user-provided Down
Converter.
c.
When a modem is taken offline, its Tx IF is automatically muted (shut down) by
the CRS-500.
Содержание CRS-500
Страница 24: ...CRS 500 1 N Redundancy System Revision 4 Preface x MN CRS 500 Notes...
Страница 38: ...CRS 500 1 N Redundancy System Revision 4 Introduction 1 14 MN CRS 500 BLANK PAGE...
Страница 54: ...CRS 500 1 N Redundancy System Revision 4 Checklists for Initial Start up and Configuration 3 6 MN CRS 500 Notes...
Страница 60: ...CRS 500 1 N Redundancy System Revision 4 Installation 4 6 MN CRS 500 BLANK PAGE...
Страница 164: ...CRS 500 1 N Redundancy System Revision 4 Ethernet Interface Operation 9 22 MN CRS 500 BLANK PAGE...
Страница 184: ...CRS 500 1 N Redundancy System Revision 4 Serial Interface Operation 10 20 MN CRS 500 BLANK PAGE...
Страница 216: ...CRS 500 1 N Redundancy System Revision 4 Appendix C C 4 MN CRS 500 Figure C 2 External EIA 485 with CDM 625 A Modems...
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Страница 220: ...2114 WEST 7TH STREET TEMPE ARIZONA 85281 USA 480 333 2200 PHONE 480 333 2161 FAX...