Harmonic ELECTRA VS - Definitions about the SDI Redundancy; SDI Redundancy Configuration

Chapter 3 ’Web User Graphical Interface’ — Operating Instructions (Tutorial)
Electra VS - Version 05.10 159
User Manual - Rev. A
SDI Redundancy Configuration
Definitions about the SDI Redundancy
SDI redundant job
A job is an SDI redundant job if it contains a SDI input and if the SDI
source is available (according to SDI topology) through at least two
distinct nodes in the Electra VS (refer to section
’Recommended SDI
Redundancy Topologies’
on page 149).
If a job is a SDI redundant job, two jobs (main and backup) are created in
the Electra VS. Only one of the two jobs is active (i.e running and
generating output streams) at a time.
Switching triggers
The switching between main and backup jobs is triggered by the
following events in the active job, ordered from the higher to the lower
criticality:
 Job not running: the job cannot be started (node unreachable, …).
 SDI sync loss (optional): no SDI signal detected.
Backup job standby activity
The Backup job standby activity determines the rapidity of switching
between the main and backup jobs.
 If backup job is running when standby, the backup job is running but
the output is muted (output streams are not generated). It is ready to
immediately broadcast the output streams when a switch is
requested. However it uses resources in the system (SDI input,
CPU,…). This mode is suitable for premium channels.
 If backup job is stopped when standby, the backup job is stopped if not
active. It is started when a switch is requested. The recovery of output
streams takes more time (few seconds). However it does not use
resources when not started.
Whatever Backup job standby activity selected, the backup job does not
use licenses.
 When triggers are raised on both main and backup jobs, the job
with the trigger with lower criticality will be set active.
 A job may contain several modules raising switching trigger (for
example two SDI inpu modules with job switching trigger set to
true). If at least one input module detects a SDI sync loss, the
job raises a switching trigger.
 A job shall contain only one module raising switching trigger. If a
job contains two SDI input modules with job switching triggers,
only one shall be set to true.