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8 kbps rs-422 interface (p2), Alarm outputs (tb1), A.2.3 alarm outputs (tb1) – Comtech EF Data SMS-451 User Manual

Page 57

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SMS-451T 1:1 ESC Protection Switch

Revision 0

B-141-1 Interface Breakout Panel

MN/SMS451.IOM

A–5

A.2.2

8 kbps RS-422 Interface (P2)

The 8 kbps RS-422 interface is provided on a 37-pin female D connector accessible from
the front of the breakout panel. Screw locks are provided for mechanical security of the
mating connector.

Signal Function

Name

Pin #

GROUND

GND

1, 19, 20, 37

1KHZ TX OCTET

TXO-A
TXO-B

3
21

8KBIT TX DATA

TXD-A
TXD-B

4
22

8KHZ TX CLOCK

TXC-A
TXC-B

5
23

8KBIT RX DATA

RXD-A
RXD-B

6
24

REQUEST TO SEND/
CLEAR TO SEND

RTS_CTSB
RTS_CTSA

25, 27
7, 9

8KHZ RX CLOCK

RXC-A
RXC-B

8
26

1KHZ RX OCTET

RXO-A
RXO-B

15
33

Note: RTS and CTS are looped together on the connector.

A.2.3

Alarm Outputs (TB1)

The alarm outputs are provided on an 8-position terminal block located on the front panel
of the breakout panel.

Signal Function

Name

Pin #

GROUND GND

1

DEMOD FAULT RELAY

DF-COM
DF-NO

2
3

BACKWARD ALARM INPUT

BWI-1
BWI-2
BWI-3
BWI-4

4
5
6
7

DEFERRED MAINTENANCE ALARM

DMA

8