Lab.gruppen PLM 20000Q - Manual (Page 7)

PLM Series Network Configuration Guide 7
avOIDINg SINgLe POINT OF FaILURe (SPF) ISSUeS 4
4.1.1 Signal type redundancy
Use of this topology allows a PLM to receive audio
and control signals from a source device using differ-
ent output types, i.e. a device which can output both
analog and AES signals simultaneously. These signals
are then designated as priorities in the auto input
section. Again, please refer to section 9.12.3.1 of
the PLM Series Operation Manual for more detailed
information on setting input priorities.
4.1.2 Signal source redundancy
This priority scheme consists of two sources, in
two locations, acting as prioritized sources in the
same network. Source redundancy also allows the
user to set up two different devices (e.g. PLMs),
feed both with the same input signal (analog or AES
digital), and then have both transfer this signal onto
Dante. Redundant signals are thus transferred to the
network. All PLMs that are required to access this
signal can do so as long as one of the two PLMs
connected to the source device remains on the
network. All remaining PLMs on the network must
be configured to access these same two devices as
the primary and secondary signal sources.
An alternate use of this function is to have
a higher prioritized source as an override.
For example, an AES signal could be dis-
tributed as a fire alarm input that can then
override the normal material distributed via Dante
and/or analog.
4.2 Network Port Redundancy
In this application, the second network port on a
PLM’s rear panel can be configured to be redundant
to the first port. If a parallel network is created, and
the source is connected to both networks, then any
single cable failure or switch failure can be overcome
without any loss of audio signal in the network. It is
also possible to survive multiple hardware failures
with this topography; however, this capability will
depend on the network configuration that is used.
More information about possible configurations is
found in section 5.