Comtech EF Data CDM-625A - Manual (Page 476)

CDM-625A Advanced Satellite Modem MN-CDM625A
CDM-625A ODU (Transceiver, BUC, LNB) Operation Revision 3
10–8
10.3.3.1.2.2 CONFIG: Mask  LNB
LNB alarm = Active (Active,Mask)
Attach to Rx alarm = No (Yes,No)()
When using L-Band, a Low-Noise Block Down Converter (LNB) may be included in the system. It
cannot be monitored and/or controlled by the modem, except for the power supply values.
For a modem in a 1:1 redundancy setup, the fault indications must be customized for
the physical setup:
1) Two modems, two LNBs in parallel – If a fault occurs on the active modem/LNB
pair and switchover is desired, the LNB mask should be configured as Attach to
Rx alarm = Yes.
2) The more common redundancy setup is Two modems in parallel, one LNB – If a
fault occurs on the active modem, switchover is desired. But, if a fault occurs on
the LNB, a switchover of modems might or might not fix the problem. If
switchover should take place, the LNB mask should configured as Attach to Rx
alarm = Yes.
If the system has no redundancy and was attached to an external audio alarm,
Attach to Rx alarm = Yes would indicate that a LNB fault has occurred, as the
fault would be included in the FORM C alarms.
First, use the ◄ ► arrow keys to select LNB Alarm or Attach to Rx alarm. Then:
• For LNB Alarm, use the ▲▼ arrow keys to select Active or Masked.
• For Attach to Rx alarm, use the ▲▼ arrow keys to select Yes or No.
Press ENTER when done.