Comtech EF Data SDM-300A - Manual (Page 210)

SDM-300A Satellite Modem Revision 6
Modem Types MN/SDM300A.IOM
6-2
6.1.1 IDR Operation
To operate the modem in the IDR 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 IDR option is a FAST feature that must be enabled using the front panel and
the Utility: Modem Type menu. Table 6-2 lists the parameters that are accessible
once the IDR modem type is enabled.
Table 6-2. IDR Parameter Settings
Parameter Front Panel Setting Reference Menu
Modem Type IDR Utility: Modem Type
TX Data/Code Rate TX-V, QPSK 3/4 Configuration: Modulator
TX-IF Output ON Configuration: Modulator
RX Data/Code Rate RX-V, QPSK 3/4 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, HDB3, or B6ZS Configuration: Interface
RX Coding Format AMI, B8ZS, HDB3, or B6ZS Configuration: Interface
Backward Alarm Control TX-1, TX-2, TX-3, TX-4
RX-1, RX-2, RX-3, RX-4
ON or OFF Utility: Interface
Service Channel Adjust TX-1, TX-2, RX-1, RX-2 levels Configuration: Interface
The IDR modem type is an open network application, primarily used for voice
circuits. IDR has a fixed overhead structure.