3 config: cnc ( search-delay – Comtech EF Data CDM-625A User Manual

Page 168

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CDM-625A Advanced Satellite Modem

MN-CDM625A

Front Panel Operation

Revision 3

6–42

Below 64 ksymbols/sec: ±1 to ±(Rs/2) kHz, where:

Rs=symbol rate in 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: (range 0-330ms)

Min: 010 ms Max: 290 ms

()

You may apply restrictions to the range of delay used by the search. This will reduce the time it

takes for the CnC algorithm to converge

Edit the Min or Max delay by using the

◄ ►

arrow keys to select a digit. Then, use the

▲▼

arrow keys to change that digit. Press ENTER.

During initial link testing, you should set Min delay to 240 ms and Max delay to 300 ms. Once

CnC finds the exact delay, you can further reduce the values, but you must take care to allow

sufficient range to accommodate changes in path delay due to Doppler.

When you are bench-testing CnC 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.

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