Figure 4-4. prime v.35 interface switch – Comtech EF Data SMS-758 User Manual

Page 78

Theory of Operation

SMS-758 Modem Protection Switch

4–18

MN/SMS758 Rev. 3

TRANSMIT CLOCK

TRANSMIT DATA

RECEIVE DATA

RECEIVE EXTERNAL

REFERENCE CLOCK

RECEIVE CLOCK

TX S/B

PRIME C/U

DATA I/O

TERRESTRIAL

DATA I/O

DATA PATH

SELECTION

RX S/B

NOTE: THE RELAYS ARE SHOWN IN THE NON-ENERGIZED

POSITION CONNECTING THE TERRESTRIAL DATA AND

PRIME MODEM CONNECTORS TOGETHER. STANDBY (S/B)

SIGNALS ARE ROUTED TO THE OFFLINE BACKUP MODEM.

TRANSMIT CLOCK

RECEIVE DATA

RECEIVE CLOCK

TRANSMIT DATA

RECEIVE EXTERNAL

REFERENCE CLOCK

MOD AND DEMOD FAULTS

DATA SWITCH

MOTHERBOARD

INSTRUCTION

DECODER

MOD RELAYS

DEMOD RELAYS

FAULTS

TRANSMIT CLOCK

TRANSMIT DATA

RECEIVE DATA
RECEIVE CLOCK
RECEIVE EXTERNAL

REFERENCE CLOCK

Figure 4-4. Prime V.35 Interface Switch