Comtech EF Data SMS-758 - Manual (Page 106)

Theory of Operation SMS-758 Modem Protection Switch
4–46 MN/SMS758 Rev. 3
3
EXT CONTROL BUS
DATA BUS AND
CONTROL SIGNALS
ADDRESS
LATCH
ADDRESS
DECODE AND
DATA BUS
BUFFER
INTERNAL
CONTROL BUS M:N
FAULT
3
3
DMD SYSTEM
FAULT
FAULT
CONTROL
RELAY-REMOTE
INTERFACE
4
MUX
'1'
RS-485
RS-232
DSR
RXD
TXD
EXT INTERFACE CONTROL
20 PRIME AND
FAULT INPUTS
BACKUP
MODEM INTERFACE CONTROL
COMMUNICATIONS
ASYNCHRONOUS
INTERFACE
DEVICE
ASYNCHRONOUS
COMMUNICATIONS
INTERFACE
DEVICE
RS-485
Figure 4-18. Address Decoder Driver (AS/1048)