Comtech EF Data RCF6001 - Manual (Page 40)

Maintenance RCF6001 Satellite Terminal
Page 4-20 TM082 - Rev. 1.0
4.2.2.1 Major Alarms
Major alarms indicate a modem hardware failure. Major alarms may flash briefly during modem
configuration changes and during power-up but should not stay illuminated.
Alarms are grouped into Transmit alarms and Receive alarms - Transmit and Receive are completely
independent.
4.2.2.2 Minor Alarms
Minor alarms indicate that a problem may 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 Alarms and Receive Alarms - Transmit and Receive are completely independent.
4.2.2.3 Latched Alarms
Latched alarms are used to catch intermittent failures. If a fault occurs, the fault indication will be latched
even if the alarm goes away. After the modem is configured and running, it is recommended that the
latched alarms be cleared as a final step.
4.3 DMD2401 Fault Tree Matrices
Tables 4-1 through 4-3 represent, in matrix form, the faults that may occur within the DMD2401. There
are three matrices; Tx Faults, Rx Faults, and Common Equipment Faults.
4.3.1 Interpreting the Matrices
The first vertical column in the Tables represent the various Faults that the modem may identify. The top
horizontal column indicates the various actions that the modem will undertake. These actions may be in
the form of a relay, a switch or an LED.
4.4 DMD2401 Bit Error Rate (BER) Curves
Figures 4-1 through 4-4 represent the BER curves for the DMD2401. Included in these specifications are
Viterbi, Concatenated Reed-Solomon and 56 Kbps Sequential.