Introduction, Description, Sms-451a description – Comtech EF Data SMS-451 User Manual
Page 15: Chapter 1. introduction, 1 description, 1 sms-451a description

1–1
Chapter 1. INTRODUCTION
This manual describes the SMS-451 Satellite Switch (Model A, E, or T), referred to in
this document as “the switch.”
1.1 Description
The following descriptions are referenced to the applicable switch.
1.1.1 SMS-451A
Description
S W I T C H S T A T U S
RE M O T E L
O C A L P
W R 1
P W R 2
R E M
L O C
DEM ODULATOR
MANUAL ON-LINE FAULT
M ODULATOR
MANUAL ON-LINE FAULT
A
A
A
B
B
AUTO
A
B
B
AUTO
A
B
B
A
SMS-451A
SATELLITE MODEM SWITCH
Figure 1-1. SMS-451A
The SMS-451A 1:1 Satellite Modem Switch (Figure 1-1 ) is a fully-automated 1:1
satellite modem (protection) switch for the following Comtech EF Data modems:
• SDM-450
• SDM-9000 with the G.703 interface.
The switch provides redundancy for one prime modem with one backup modem.