Comtech EF Data CDM-760, Installation And Operation Manual

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Front Panel Operation Revision 4
CDM-760 Advanced High-Speed Trunking Modem MN-CDM760
6–11
Data Rate Values:
The maximum limits for the Data Rate are based on a symbol rate range from 0.1 to 150 Msps.
The actual minimum and maximum data rates are dependent on Network Spec, Framing mode,
Interface type, Modulation type and FEC Code Rate settings. The upper range of the data rate is
also affected by the FAST option(s) installed.
The Data Rate adjusts automatically if changes made to any of the higher-priority parameters
cause the data rate to become invalid.
Table 6-3 , Table 6-4 , and Table 6-5 list the available modulation and code rate combinations.
These tables have some roundoff of the last number in the Data Rate Range columns.
(CONFIG: Tx) Data

Tx Symbol Rate
You can change the Tx Symbol Rate while the modem is in MultiStream Mode. The
modulator turns the Tx Carrier OFF while programming.
Tx Symbol Rate = 30000.000 ksps
(


)
Use the
 
arrow keys to select a digit, and then use the

arrow keys to change that digit.
Press ENTER .
The Data Rate value changes as you change the Symbol Rate value. The value of the Data Rate
depends upon the code rate, modulation type, and mode type.
When you change the modulation, code rate, or other parameters, the modem attempts to
maintain the same Symbol Rate as long as it is still in range when you change one of the other
parameters. The modem rejects any data or symbol rate change that is not in the valid range.
You must first change the Modulator Code Rate or mode when the modem rejects a new rate.
Table 6-3 , Table 6-4 , and Table 6-5 list the available modulation and code rate combinations.
These tables have some roundoff of the last number in the Data Rate Range columns.