Config: Cnc  Config: Cnc  Freq-Offset; Config: Cnc  Search-Delay - Comtech EF Data CDM-625A Installation And Operation Manual

CDM-625A Advanced Satellite Modem
Front Panel Operation
• APC,Side B,C-band
• APC,Side B,Ka-band
6.2.1.8.2 CONFIG: CnC  CONFIG: CnC  Freq-Offset
CnC Frequency Offset:
Use this menu to enter the maximum expected frequency offset between the outbound
interferer and the desired inbound. It normally corresponds to the demod acquisition range.
Use the arrow keys to edit the CnC Frequency Offset value, and then press ENTER. The
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upper limit of Frequency Offset is determined by the Rx symbol rate:
• Below 64 ksymbols/sec:
• Between 64 and 389 ksymbols/sec: ± 1 up to a maximum of ± 32kHz
• Above 389 ksymbols/sec: ±1 to ± (0.1Rs) kHz, up to a maximum of ± 200 kHz
This range is pre-calculated and displayed in parentheses for reference.
6.2.1.8.3 CONFIG: CnC  Search-Delay
CnC Search Delay:
To reduce the time taken for the CnC algorithm to converge, you may apply restrictions to the
range of delay used by the search. 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.
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.
To edit the Min or Max delay, use the
arrow keys to change that digit. Press ENTER when done.
▲▼
• APC,Side B,X-band
±1 to ±(Rs/2) kHz
Rs=symbol rate in ksymbols/sec
Min: 010 ms Max: 290 ms
◄ ►
(range 1-032)
+/-015 kHz
, where:
(range 0-330ms)
arrow keys to select a digit to edit, and then use the
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Revision 0
MN-CDM625A
• APC,Side B,Ku-band
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