Comtech EF Data SMS-458B - Manual (Page 88)

SMS-458B Modem Protection Switch Revision2
Maintenance MN/SMS458B.IOM
5–2
5.1.3 Demodulator Operation Fault
A DEMOD fault occurs when a demodulator backup operation fails. Any of the
following can be the cause of failure:
• More failed demodulators than available backups.
• No compatible backup available.
• All backups are in use.
• All demodulators on a downlink faulted.
5.1.4 M:N Faults
An M:N fault occurs when a communication, configuration, setup, and/or power supply
failure occurs. Any of the following can be the cause of failure:
• Modem communication failure due to incorrect:
! Address
! Baud
rate
! Parity
! Interface
connection
• Failure to verify configuration data.
• Missing configuration data.
• A backup modulator or demodulator that is not compatible with any prime.
• A prime modulator or demodulator that is not compatible with any backup.
• A missing modem address specification.
• A missing channel unit address specification (version 2.02 or newer).
• A missing modem interface specification.
• A missing demodulator downlink specification.
• High or low +12V power supply.
• High or low -12V power supply.
• High or low +5V power supply.
• One of the power supplies is turned off.