Comtech EF Data SDM-300A - Manual (Page 211)

SDM-300A Satellite Modem Revision 6
Modem Types MN/SDM300A.IOM
6-3
6.1.2 IBS Operation
To operate the modem in the IBS configuration, the following cards must be
installed in the modem:
• Overhead G.703/IDR/IBS/ASYNC/AUPC/D&I card (PL/5305-1)
• 50-pin D relay adapter card (PL/5509)
The IBS option is a FAST feature that must be enabled using the front panel and
the Utility: Modem Type menu. Table 6-3 lists the parameters that are accessible
once the IBS modem type is enabled.
Table 6-3. IBS Parameter Settings
Parameter Front Panel Setting Reference Menu
Modem Type IBS Utility: Modem Type
TX Data/Code Rate TX-V, QPSK 1/2 Configuration: Modulator
TX-IF Output ON Configuration: Modulator
RX Data/Code Rate RX-V, QPSK 1/2 Configuration: Demodulator
TX Clock Source
TX Terrestrial, Internal, Ext. Reference Configuration: Interface
Buffer Clock Source Satellite, TX Terrestrial, Internal, Ext.
Reference
Configuration: Interface
TX Coding Format AMI, B8ZS, or HDB3 Configuration: Interface
RX Coding Format AMI, B8ZS, or HDB3 Configuration: Interface
The IBS modem type is an open network application, primarily used for data
circuits. IBS has a variable overhead structure that is dependent on the transmitted
data rate.