Q-Flex Satellite Modem Installation and Operating Handbook
7-10
7.3 1:1 Redundancy Operation
7.3.1 Overview
Two modems can operate as a 1:1 redundant pair using a single interconnecting lead,
two power splitters/combiners and cable forms to parallel up the terrestrial interfaces of
both units. Both modems operate normally with respect to incoming data and IF signals,
but only one modem enables its satellite and terrestrial outputs at any point in time.
Figure 7-8
illustrates how a 1:1 redundant pair is configured.
Figure 7-8 Modem 1:1 Redundancy System
It is possible to replace the offline modem in a 1:1 pair without interrupting traffic.
7.3.2 Switching Operation
If a particular modem is required to be the online modem then this should be powered up
first. Alternatively, a manual switchover should be invoked once the modems have
powered up. This is achieved by selecting the
Switch to standby
control on the
Edit-
>Redundancy->1:1
menu, which momentarily simulates a failure in the operational unit.
The Standby modem monitors its own status and the status of the online modem
continually and will switch over to become the online modem automatically in the event
that a fault occurs with respect to the online modem. The types of faults that will cause a
switchover are configurable. Both unit and traffic faults can cause a switchover. Traffic