Chapter 5. Maintenance; Fault Descriptions; Modulator Operation Fault; Demodulator Operation Fault - Comtech EF Data SMS-758 Installation And Operation Manual

5.1 Fault Descriptions

The FAULT menu, [NEXT], and [PREV] keys allow the operator to determine the cause
of any switch faults indicated by a red LED.
The following sections describe the faults and their probable causes.

5.1.1 Modulator Operation Fault

A MOD fault occurs when a modulator backup operation fails. The cause of the failure
can be one of the following:
•
•
•

5.1.2 Demodulator Operation Fault

A DEMOD fault occurs when a demodulator backup operation fails. The cause of the
failure can be one of the following:
•
•
•
•
MN/SMS758 Rev. 3
More failed modulators than available backups.
No compatible backup available.
All backups in use and/or faulted.
More failed demodulators than available backups.
No compatible backup available.
All backups in use.
All demodulators on a downlink faulted.
Chapter 5.
MAINTENANCE
5–1