Comtech EF Data SDM-650B - Manual (Page 303)

SDM-650B Satellite Modem Trojan Interface
Rev. 5 G–7
G.4 Configuration Guide
Menu Selection Options
BBLoopBk (Baseband Loopback) OFF/ON
EXT_REF (Station Clock Freq) n kHz (must be evenly divisible by 8 kHz)
REF_CLK (Ref Clock Source) Transmit
Receive
External (MC)
Internal (SCT)
TX_clock External (TT)
Internal (Synthesizer)
RX_clock Normal/Inverted
BUF_CNTR (Center Doppler Buffer)
YES/NO
BUF_DPTH (Buffer Depth, bits) 512 bit
1024 bit
2048 bit
4096 bit
8192 bit
16384 bit
32768 bit
Notes:
1. Reference clock source is temporarily set to Receive clock during baseband
loopback.
2. Do not set TX_clock to REF_CLK when REF_CLK source is TX_clock, as
this makes an unstable loop.
3. Send Data (SD) must be long-term synchronous with Send Timing (ST),
unless REF_CLK source is Transmit and TX_clock is External (this is the
recommended dejitter configuration).
4. EXT_REF frequency selection is a “don’t care” unless REF_CLK is selected
to External. The M&C processor automatically sets the proper division rate
for the clock synthesizer in the other cases.
G.4.1 Modulator/Coder Defaults
TXA Transmit Filter A 7/8 code rate, 56 kbit/s
TXB Transmit Filter B 3/4 code rate, 56 kbit/s
TXC Transmit Filter C 1/2 code rate, 56 kbit/s
TXD Transmit Filter D 1/2 code rate, 64 kbit/s
TXR Transmit Rate Selected “A” 7/8, 56 kbit/s
TX_Freq Transmitter Frequency 70 MHz
RF_Out RF Output OFF
TX_Power Transmit Power Level -10 dBm
Scramblr Scrambler ON
DifEncdr Differential Encoder ON
CW_Mode Continuous Wave Mode OFF