Comtech EF Data SDM-309B - Manual (Page 183)

Remote Control SDM-309B Satellite Modem
B-B–6 MN/U-SDM309B Rev. #
Status Only: <add/DF_”cr”
Response: >add/DF_nn.nnnn”cr””lf”]
4.2.2 Demodulator Rate
The demodulator has four symbol rate filters. Each filter is for a specific symbol rate.
The data rate and decoder rate for each filter must be established upon initial
demodulator installation and when circumstances indicate the need to do so. Filters are
designated as A, B, C, and D. If a filter is not physically present in the system it may be
assigned N/A (not assigned). Additionally filters which are factory programmed may not
be remotely programmed and will return the "error 5" message when a programming
command is issued.
*VARIABLE RATE DEMODULATOR OPTION*
Demodulators with the variable rate option installed may have four preprogrammed rates
available by using the filter rate assignment commands. These rates are selected using
the standard ‘sDRx_" commands. Modems that have the variable rate option installed
will also respond to the special ‘sDRV_" command. This allows for truly variable rate
control while maintaining compatibility with previous systems.
4.2.2.1 Demodulator Filter Rate Assignment
Command: <add/ADRx_nnn_mmmm.m”cr” (x = A,B,C, or D Filter designator)
(nnn = 1/2,3/4, or 7/8 Decoder rate)
(mmmm.m = 48.0 to 4080.0 Data rate)
Response: >add/ADRx_nnn_mmmm.m”cr””lf”]
Status Only: <add/ADRx_”cr”
Response: >add/ADRx_nnn_mmmm.m”cr””lf”]
Note: The parameters nnn_mmmm.m may be replaced by N/A to indicate no assignment.
Example:
Command: <add/ADRx_N/A”cr”
Response: >add/ADRx_N/A”cr””lf”]
4.2.2.2 Select Demodulator Rate
Command: <add/SDRx_”cr” (x = A,B,C, or D Filter designator)
Response: >add/SDRx_”cr””lf”]
Status Only: see DR command.
Note: If the MODEM is commanded to a filter (rate) which is not assigned (N/A) the
error 2 message will be returned.