Figure A-5. Async/Aupc Block Diagram - Comtech EF Data SDM-300A Installation And Operation Manual

Options
The ASYNC interface PCB also provides its own Doppler buffer, which has a maximum
depth of 32 ms at the highest terrestrial data rate. Buffer fill status can be checked in the
Monitor menu on the front panel of the modem. Depth selection and centering of the
buffer are provided in the Configuration Interface menu.
T
E
R
R
E
S
T
R
I
A
L
A–20
G .7 03
T E R R D ATA
EIA-422
T E R R C LO C K
V.3 5
IN T ER FAC E C N T SIG N A LS
AS Y N C D ATA
EIA-485
EIA-232
G .703
TE R R D ATA
EIA-422
TE R R C LO C K
V.3 5
IN T ER FA C E SIG N AL
A S Y N C D ATA
EIA-485
EIA-232

Figure A-5. ASYNC/AUPC Block Diagram

IN P U T
F IFO
M U X
P LL
IN T E R FAC E C N T S IG N A LS
U A R T
AS Y N C D ATA
TER R DATA
R X C LK
ENABLE
4 OU TPUT
B U FF E R
CLK SO URCES
P LL
U A RT
SDM-300A Satellite Modem
A U P C D ATA F R O M M & C
TE R R D ATA
TE R R O V E R H E A D C LO C K
M &C C O N TR O L
AU P C D ATA TO M & C
R X D ATA
D M U X R X C LK
INT ER FACE
SIGN AL S
M
O
D
U
L
A
T
O
R
D
E
M
O
D
U
L
A
T
O
R
Rev. 4