Comtech EF Data RCS10 - Manual (Page 53)

Operation RCS10 Redundant Communication System
Page 3-6 TM058 - Rev. 2.3
3.1.11 SNMP Control
The Simple Network Management Protocol (SNMP) is used to monitor and control the RCS10
Switch parameters when the Switch is connected to a network. On a network, a client is one host,
an SNMP Manager communicates with a server in another host, an SNMP Agent. The Manager, a
remote M&C, requests the agent (RCS10 Switch) to read or write information (objects) in a
Management Information Base (MIB) resident in the Agent. Refer to Addendum A in the back of the
manual for additional information and a complete compilation of the RCS10 MIB.
3.1.12 Manual/Automatic Backup Modes
The switch operates in both Manual and Automatic backup modes. In Automatic Mode, a failed
unit will be automatically replaced with a Backup unit if a Backup unit is available. However, if an
online Modulator or Demodulator fails while it is set to Manual mode, it will not be automatically
backed up.
There are two types of Automatic backup modes; Revertive and Non-revertive. In Automatic
Revertive mode, a failed unit is replaced with the backup unit after the fault delay time has passed.
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 backup the newly failed unit. In Automatic Non-Revertive mode, a failed unit is replaced by
the Backup unit after the Fault Delay time has elapsed. 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 using the front panel
selection.
3.1.13 Standby Modes
A backup unit can be set to three standby modes; self-test, hot standby and preemptable. In self-
test mode, the backup Modulator’s IF output is looped into the IF input of the backup demodulator
and performance is continually checked.
In hot standby mode, the backup modulator and/or demodulator settings are matched to that of a
priority online modulator and/or demodulator so that if a modulator and/or demodulator fails, it will
immediately be replaced by a backup. The other modems are still monitored and will be backed up,
but the switchover will be longer.
In preemptable mode, the backup modulator or demodulator is used online. However, if another
modem, covered by the backup fails, the backup will be preempted and will backup the failed
modem.
3.1.14 Test Port Operation (Operational on Backup Modem 2 Only)
The backup channel’s terrestrial interfaces can be used to test the operation of the channels that
they cover. On the modulator side, the test port can be tied to any modulator that the backup is
monitoring and used to inject baseband test signals into the online modem. On the demodulator
side, the test port is used to monitor the demodulator output of the online modem. The user can
set the test port selections by specifying the modulator and/or demodulator that is connected to a
backup’s Mod and Demod test ports from any of the available user interfaces.
3.1.15 Backup/Online
When a modem is first installed into the RCS10, it is set up as an online unit by default. It is up to
the user to change its configuration from ‘online’ to ‘backup,’ and to set up a backup pool for it if
configured as a backup, or add it or remove it from a backup pool if set up as online. These
configuration settings are performed on the front panel through the key.