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Table of Contents
Dual Output EL Switch on loss of all output interfaces
May 2024
Introduction
Okay, it's a long title, but what does it mean? If we look at the nCompass map below, we can see that the Encoders are outputting, but only a single interface is show, even though we are outputting on two interfaces (eno3 and eno4)
when using dual outputs, if either output fails, we get a Critical Alarm. This means that the second encoder will take over, even though we still have a valid output from one of the output interfaces on the first encoder.
Remove Dual Output Prevention from EL
If you are using DOP (dual output prevention) in the Encoders, you need to turn this off.
From the General tab on the Encoder, untick Dual Output Prevention.
In a 1+1 EL configuration, Dual Output Prevention means that only one encoder is outputting, this stops duplicate streams on the network. For the Mux, this isn't an issue. With DOP on, when the first encoder has an interface failure (Critical) then the second Encoder will take over, and the first Encoder stops outputting.
This causes an issue because there is a short period of time where neither Encoder is outputting, While the time for this condition is very short, it is long enough that the active Mux will have no inputs from either Encoder, and the active Mux will switch to the backup. Disabling DOP on the Encoders will stop this happening.