Comtech EF Data CDM-710 Installation And Operation Manual page 54

CDM-710 Broadcast Satellite Modem
Front Panel Operation
When modulation, code rate and other parameters are changed the modem attempts to
maintain the same symbol rate, provided it is still in range when one of the other
parameters is changed.
The valid range of Symbol Rate and Data Rate Range for DVB-S2, DVB-S and DVB-DSNG are
shown in the following table. When programming a new data or symbol rate the modulator will
not accept it unless it is in the range. If a new rate is not accepted, change the Modulator Code
Rate or Mode. There is some round off in the data rate ranges in the last digit. The first table is
for the standard FEC frame and the second table is for the short frame. QPSK 1/4, 1/3 and 2/3
data is for information only.
The tables are based on a 188 byte frame format. When a 204 byte format is selected the data
rate increases by 204/188.
5–14
Revision 9
MN/CDM710.IOM