Comtech EF Data SDM-300A - Manual (Page 348)

SDM-300A Satellite Modem Revision 6
Troubleshooting MN/SDM300A.IOM
18–12
18.3.2 Faults/Alarms Display
General fault, status, and alarm information are indicated by 10 LEDs located on the modem’s
front panel.
• A fault (red LED) indicates a fault that currently exists in the modem.
• When a fault occurs, it is stored in the stored fault memory, and indicated by the single
yellow LED.
• The LED is turned off when the fault clears. If the fault clears, the occurrence is also
stored.
A total of 10 occurrences of any fault can be stored. Each fault or stored fault indicated by a
front panel LED could be one of many faults. To determine which fault has occurred, use the
Fault or Stored Fault front panel menu.
Alarms are considered minor faults, which will not switch the modem offline in a redundant
system. Alarms are shown in the Fault or Stored Fault front panel menu by a reversed contrast
(white on black) character that appears at the display panel.
18.3.3 Faults/Alarms Analysis
This section describes the possible problems and actions to take for the following faults:
• Modulator
• Demodulator
• Transmit interface
• Receive interface
• Common equipment
• Backward
alarm