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4 performance specification – Comtech EF Data SMS-758 User Manual

Page 26

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Introduction

SMS-758 Modem Protection Switch

1–10

MN/SMS758 Rev. 3

1.4 Performance Specification

The operating specifications of the switch are described in Table 1-1.

Table 1-1. SMS-758 Performance Specification

Operation

Number of Online Modems

Expandable from 1 to 8 with plug-in prime
interface switch modules (the modems can be
of different data rates and interfaces, as long
as the backup modems are compatible).

Number of Backup Modems

Expandable from 1 to 2 with plug-in backup
interface switch modules (IDR AS/0895
interface limits the backup to one).

Data Interfaces

DS-1 and G.703, V.35, RS-422/449/
MIL-STD-188-114, IBS, IDR, or D&I.

IF Frequency Response

50 MHz to 180 MHz.

Downlinks

Each demodulator is configurable for 1 of 4 or
7 downlink connections.

Uplinks

Eight modulator outputs may be externally
combined/divided for any number of uplinks.

Prime Modulator to Output Loss

Less than 1 dB.

Backup Modulator to Prime Output Loss

Less than 1 dB.

Manual Delay Switch-Over Time:

Modulator

Demodulator

0 to 127.5 sec., in 0.5 sec. steps.

0 to 127.5 sec., in 0.5 sec. steps.

Auto Delay Switch-Over Time:

Modulator

Demodulator

< 1 sec.

< 3 sweep periods of the back-up
demodulator.

Switch-Over Priority

One of three priority levels available
independently for each modulator and
demodulator, if independent mod/demod
firmware is used. Modulators and
demodulators will switch simultaneously with
modem switch firmware.

Remote Control Interfaces:

External control

Modem Control

RS-485 or RS-232C. Baud rates from 110 to
9600, Even or Odd parity, Addresses from
1 to 255.

RS-485, Baud rate 9600, Even parity,
Addresses from 1 to 255.

Batteries

M&C: NiCad, 30 day memory retention.
48 hr. charge time.