Comtech EF Data CDM-425, Installation And Operation Manual

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CDM-425 Advanced Satellite Modem
Revision 0
ODU (Transceiver, BUC, LNB) Operation 10–8 MN-CDM-425
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.
Use the
◄ ►
arrow keys to select LNB Alarm or Attach to Rx alarm .
•
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.