Radio Live Engine is given as a standalone application Etere.RadioLive.Engine.exe inside C:\Program Files (x86)\Etere folder, and this executable file can be launched with two parameters, for which the default values are:
Etere.RadioLive.Engine.exe 1 MAIN
"1" is the station number, and MAIN is the engine's status. If you want to launch it as MAIN or BKP (backup), just substitute the second value with one of those mentioned.
Note: if the Parameters option "Use Main/Bkp" is active, you'll also have on the upper section a status indicator which shows the current status of the engine and which one is OnAir
Radio Live Engine is also able to intercept SCTE 35 and 104 signals from UDP sources (file or SDI traffic)