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.
PLM Series Network Configuration Guide 7
