Comtech EF Data RCS10 User Manual
Page 55
Operation
RCS10 Redundant Communication System
Page 3-8
TM058 - Rev. 2.3
(‘0’ to ‘9’), then pressing the ‘Enter’ key. An input can be aborted at any time by pressing the ‘ESC’
key. If an invalid value is entered, an error message will be displayed on the terminal.
Following a valid input, the RCS10 places the new settings into nonvolatile RAM, changing the
switch configuration immediately and storing the configuration for the next time the unit is powered
up.
3.3
Backup Handler
The switch operates both in manual and automatic backup modes. In automatic mode, a failed unit
will be automatically replaced with a backup unit if a backup is available. However, if an online
Modulator or Demodulator fails while it is set to manual mode, it will not be automatically backed-
up. Backup mode is accessed in the
To manually back up a modem, set the desired backup (1 or 2) to ‘Manual’ in the
menu, select the backup that is in ‘Manual’ mode and enter the number of the prime modem to be
backed up. Backup 2 can select available modems between 1-8. Backup 1 can select available
modems between 1-8 or 1-9 if backup 2 is set for traffic.
There are two types of Automatic Backup Modes: Revertive and Non-revertive. In Revertive mode, a
failed unit is replaced by the Backup unit after the fault delay time passes. The failed unit continues
to be monitored, and if the failure condition clears itself and another failure occurs with no available
Backup units, then the SWITCH will automatically unback the passing unit and then back up the
newly failed unit.
In Non-revertive mode, a failed unit is replaced by the Backup unit after the fault delay time passes.
However, if the failure condition clears itself, the SWITCH does not return the failed unit back online
if another monitored unit fails and no Backup units are available. The failed channel can be
unbacked manually by setting the BACKUP unit to manual using the front panel
selection located in
There are two types of delays available to the user in the RCS10 Switch. The Fault Delay time for
each Modulator and Demodulator is preprogrammed by the operator to be between 0 and 299.9
seconds through the
a good signal during the delay time. If the signal returns, no switchover takes place and the timer is
reset. If more than one unit fails, the first one to timeout will be the first one that is replaced until no
Backup units are available.
If the unit is still inoperative at the end of the delay time, and the backup unit is available, then the
backup takes place. If the backup unit is in both automatic and hot standby modes, then if the
online unit (the one the backup is standing by for) fails, it will automatically be backed-up regardless
of fault delay.
The other type of delay available to the user is the Acquisition Delay. This is the amount of time it
takes the Demodulator to acquire lock. When a Prime fails, the backup unit has up to the
programmed Acquisition Delay to lock. If it fails to lock, a Major Alarm is asserted along with a
descriptive event logged in the Event Buffer. Backup status faults will also be generated to ‘Flag’ the
unsuccessful backup.
The Backup Modem has up to three attempts to successfully backup a prime. If it fails, an ‘F’ or
‘FF’ is displayed on the Backup Summary front panel screens and the Prime is removed from the
‘Backup Modem’ backup pool. No further backup attempts are made.
Nine different priority levels may also be set and are used by Revertive switching to make a decision
to drop a link that is already being backed up in favor of another link of higher importance. As long
as a free backup modem remains, that backup will handle the outage. Should no free backups
exist, then any outage is considered for backup on a priority basis. Priority is set with 1 being