Alarm Masks - Comtech EF Data DMD1050TS Installation And Operation Manual

5.2.2 Alarm Masks

CAUTION: DATA LOSS POSSIBLE
Masked alarms can cause undesirable modem performance.
The DMD1050TS does a high degree of self-monitoring and fault isolation. The alarms for these
faults are separated into categories:
•
Active Alarms
•
Common Equipment Faults
Alarms recorded in the event buffer are the same as those in the alarm buffer.
You can mask certain alarms. When an alarm is masked, the Fault Relays are not asserted, but
the Alarm is shown. This feature is very helpful during debugging, or to lock out a known failure.
5.2.2.1 Active Alarms
5.2.2.1.1 Major Alarms
Major Alarms mean a modem hardware failure. Major Alarms can flash briefly during modem
configuration changes and during power-up, but should not stay lit. Alarms are grouped into
Transmit and Receive Alarms. Transmit and Receive alarms are completely independent.
5.2.2.1.2 Minor Alarms
Minor Alarms mean that a problem can persist outside the modem, such as loss of Terrestrial
Clock, loss of terrestrial data activity, or a detected transmit or receive AIS condition.
Alarms are grouped into Transmit and Receive Alarms. Transmit and Receive alarms are
completely independent.
5.2.2.2 Common Equipment Faults
Common equipment faults mean hardware or configuration problems in the modem that affect
both transmit and receive operation. Most common faults mean a hardware failure in the modem,
such as a bad power supply. Common faults for the External Reference and External Clock
mean a bad modem configuration, not a hardware failure.
5.2.2.3 Latched Alarms
Latched Alarms are used to catch intermittent failures. If a fault occurs, the fault indication is
latched, even if the alarm goes away. After the modem is configured and running, it is
recommended that you clear the Latched Alarms as a final step.
Maintenance and Troubleshooting
DMD1050TS Satellite Modem Board
5–4
Revision 1
MN-DMD1050TS