Comtech EF Data SDM-300L3 - Manual (Page 202)

SDM-300L3 Satellite Modem Revision 1
Modem Types MN/SDM300L3.IOM
5–2
5.2 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
• 50-pin D relay adapter card
The IDR option is a FAST feature that must be enabled using the front panel and the Utility
Modem Type menu. Table 5-2 lists the parameters that are accessible once the IDR modem type
is enabled.
Table 5-2. 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 Demodulator
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.