Comtech EF Data CDM-750, Installation And Operation Manual

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CDM-750 Advanced High-Speed Trunking Modem Revision 2
Introduction MN-CDM750
1–6
•
1:1 and 1:N redundancy switching available
1.3.1 Physical Description
The CDM ‐ 750 Advanced High ‐ Speed Trunking Modem is constructed as a 1RU ‐ high rack ‐
mounting chassis. Handles at the front allow easy placement into and removal from a rack. The
unit can be free ‐ standing if desired.
•
Sect. 1.4 CDM ‐ 750 Specifications
•
Sect. 2.1 Installing into a Rack Enclosure
•
The modem is modular in design and is comprised of two main card assemblies:
o
The main card includes all of the interface circuits (including Dual and Optical GigE, 10
MHz external reference, redundancy, etc.), the DVB ‐ S2 Encapsulator/Decapsulator or
alternate framing/deframing, and the EIA ‐ 232/422 and Ethernet M&C interfaces.
o
The modem card performs all signal processing functions of modulation, demodulation,
and frequency conversion to 70/140 MHz or L ‐ Band. This card provides ID capability so
that M&C can identify which card is installed.
Additionally:
ƒ
Based on “Adaptive Cancellation” technology, the DoubleTalk
TM
Carrier ‐ in ‐ Carrier
®
option (referred to throughout this manual as CnC ) allows transmit and receive
carriers of a duplex link to share the same transponder space. This plug ‐ in daughter
card can either be factory ‐ installed at the time of ordering, or field ‐ installed by the
user.
Appendix D. D
OUBLE
T
ALK
C
ARRIER
‐
IN
‐ C
ARRIER
OPTION
ƒ
An optional K4 GZip lossless compression card plugs into an internal expansion slot
on the modem card.