Comtech EF Data CDM-625, Инструкция по установке и эксплуатации

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CDM-625 Advanced Satellite Modem Revision 1
Front Panel Operation MN-0000036 (Ref MN/CDM625.IOM)
5.4.8 CONFIG: CnC
Carrier in Carrier: Mode Freq-Offset
Search-Delay PMSI (
34
)
See
Chapter 10. DoubleTalk
®
Carrier-in-Carrier
®
OPTION
for more information about this
feature.
Select
Mode
,
Freq-Offset
,
Search-Dela
y, or
PMSI
using the ◄ ► arrow keys, then press
ENTER
.
5.4.8.1 CONFIG: CnC
Æ
Mode
CnC Mode: Off (Off,On)
(
v
)
Note:
CnC operation requires installation of the DoubleTalk
®
Carrier-in-Carrier
®
module. In
addition to installing the CnC module, the user needs to purchase one of several available FAST
options to provide capability to a maximum of 25Mbps. See
Chapter 1. INTRODUCTION
for
more information about purchasing FAST options.
Select
Off
or
On
using the
▲ ▼
arrow keys, then press
ENTER.
If the module (card) is not present, the menu displays as follows:
CnC Mode: Off (Off,On)
Card not installed (
v
)
With no module installed, CnC Mode will be ‘Off’, and this menu may not be edited.
5.4.8.2 CONFIG: CnC
Æ
Search Delay
CnC Search Delay: (range 0-330ms)
Min: 010 ms Max: 290 ms (
34v
)
To reduce the time taken for the CnC algorithm to converge, the user can restrict the range of
delay the search uses. During initial link testing it should be set to 240 ms (min) and 300 ms
(max). Once CnC has found the exact delay the value can be further reduced, but care should be
taken to allow sufficient range to accommodate changes in path delay due to Doppler. This is of
particular concern if the satellite being used has a highly inclined orbit.
IMPORTANT
If CnC is being bench-tested with two units in a back-to-back configuration, the
minimum delay should be set to 0 ms, and the maximum to 20 ms. This takes
into account the lack of satellite delay.
Select the delay to edit using the ◄ ► arrow keys, then edit the value of each delay using the
▲ ▼
arrow keys. Press
ENTER
when done.
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