Comtech EF Data SDM-650B - Manual (Page 172)

Data Rates and Filters SDM-650B Satellite Modem
A–6 Rev. 6
A.2 Variable Rate Filters
A.2.1 Data Rate Change Instructions
1. Turn OFF modem power switch.
2. Remove the modulator card (AS/0773) using the black card ejectors. Verify the
daughter card is a variable rate filter (AS/0930). If not, refer to Section A.1.
3. Re-install the modulator card into the modem chassis.
4. Remove the demodulator card (AS/0778) using white card ejectors. Verify the
daughter card is a variable rate filter (AS/0929). Re-install the demodulator card
into the modem chassis.
5. Remove the M&C board and JP6 (battery ON/OFF). Short the leads of capacitor
C12. Replace the battery jumper to the ON position, and re-insert the M&C card
into the modem.
6. Turn ON the power switch.
7. Go to the Utility menu on the front panel, and program the time, day, TXA, TXB,
TXC, TXD, RXA, RXB, RXC, and RXD to the new data/code rates.
8. Go to the Config menu on the front panel, and select either the desired TX and
RX rate, or TXV and RXV. Enter the desired data/code rates into the menu and
press [ENTER]. Only data rates up to and including 2048 kbit/s with a variable
rate filter can be selected. Refer to Table 6-2 for a list of the programmable data
rates of the variable rate filters. Enter the Config menu, and turn ON the RF
output.
The software change is complete.