Comtech EF Data SMS-458B - Manual (Page 25)

SMS-458B Modem Protection Switch Revision 2
Introduction MN/SMS458B.IOM
1–9
1.6 Specification
The operating specifications for the switch are described in Table 1-1.
Table 1-1. SMS-458B Specification
Operation
Number of Online Modems
Expandable from 1 to 4 with plug-in prime
interface switch modules (the modems can be of
different data rates as long as the backup modems
are compatible).
Number of Backup Modems 1 backup modem with a plug-in backup interface
switch module.
Data Interfaces ASI
ECL
G.703
Return Loss > 15 dB.
IF Frequency Response 50 to 180 MHz.
Downlinks Each demodulator is configurable for 1 of 4
downlink connections.
Prime Modulator to Output Loss ≤ 1 dB
Backup Modulator to Prime Output Loss ≤ 1 dB
Manual Delay Switch-Over Time Modulator: 0 to 127.0 sec., in 0.5 sec. steps
Demodulator: 0 to 127.0 sec., in 0.5 sec. steps
Auto Delay Switch-Over Time Modulator: < 1 sec
Demodulator: < 3 sweep periods of the back-up
demodulator.
Switch-over Priority 1 of 3 priority levels independent for each
modulator and demodulator (modulators and
demodulators may switch simultaneously in certain
applications).
Remote Control Interfaces External control: EIA-485 or EIA-232
Baud rates from 110 to 9600.
Parity: Even or Odd.
Addresses from 1 to 255.
Batteries M&C: NiCad, 30-day memory retention.
48 hr. charge time.
Alarm Reporting Controller Fault Alarm: Form-C relay contact to
indicate controller or power supply failure.
System Fault Alarm: Form-C relay contact to
indicate any non-catastrophic failure.
Demodulator Fault Alarm: Form-C relay contact to
indicate all demodulators faulted and a probable IF
loss.