Figure 4-4. Interface Block Diagram - Comtech EF Data SDM-300A Installation And Operation Manual

SDM-300A Satellite Modem
T X
O V E R H EA D
B A S E B A N D
L O O P B A C K
T X T E R R
D ATA
R X T ER R
D ATA
R X O V ER H E A D
B A C K W A R D
A L A R M S
M O D E M FA U LT S
( F O R M C )
M O D E M FA U LT S
(T T L )
Rev. 4
O V E R H E A D
R ECE IVER S
P RO CE SS OR S
LINE
RECEIV ERS
S C T
E X T
LIN E
P LESIO CH RO NO US
DRIVER S
R XC L K
RX
SC T
C L O C K
E X T
M UX
T X CL K
H I S TA B
LIN E
DR IVE RS
BW A
FORM C
R ELAYS
F LT
F O R M C
R E L AY S

Figure 4-4. Interface Block Diagram

TX
OVER HEAD
M U X
TX
C L O C K
MU X
D R O P /IN S E R T
R X
O VER HE AD
BU FFE R
DEMU X
O V E R H E A D
PR OC ES SO RS
R EL AY
DR IVE RS
MICRO -
R EL AY
D RIVER S
CO NTR OLLER
TTL
DR IVE RS
Theory of Operation
INTER FACE
LOO PB ACK
T X S AT
D ATA
R S C O D E C
R XS AT
DATA
4–13