Comtech EF Data SDM-300A - Manual (Page 212)

SDM-300A Satellite Modem Revision 6
Modem Types MN/SDM300A.IOM
6-4
6.1.3 D&I Operation
To operate the modem in the Drop & Insert 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 D&I option is a FAST feature that must be enabled using the front panel and the
Utility:Modem Type menu Table 6-4 lists the parameters that are accessible once the
D&I modem type is enabled.
Table 6-4. D&I Parameter Settings
Parameter Front Panel Settings Reference Manual
Modem Type D&I Utility: Modem Type
TX Data/Code Rate TX-V, QPSK 1/2 (NX64) Configuration: Modulator
TX-IF Output ON Configuration: Modulator
RX Data/Code Rate RX-V, QPSK 1/2 (NX64) Configuration: Demodulator
TX Clock Source TX Terrestrial Configuration: Interface
Buffer Clock Source Insert Clock Configuration: Interface
TX Coding Format HDB3 Configuration: Interface
RX Coding Format HDB3 Configuration: Interface
Drop Format E1CCS/E1CAS (E1) Configuration: Interface
Insert Format E1CCS/E1CAS (E1) Configuration: Interface
In D&I operation, the transmit data rate is a fractional portion of the trunk T1 or E1
terrestrial input. The N stands for the number of 64 kbps time slots available for
transmission. Table 6-5 TX data rates for D&I with the corresponding number of time
slots available for each data rate.
Table 6-5. N x 64 Chart
Time Slots TX Data Rate Time Slots TX Data Rate
1 64 kbps 10 640 kbps
2 128 kbps 12 768 kbps
3 192 kbps 15 960 kbps
4 256 kbps 16 1024 kbps
5 320 kbps 20 1280 kbps
6 384 kbps 24 1536 kbps
8 512 kbps 30 1920 kbps