ETC ION Operation Manual page 326

The Ion's LCD displays the current status of the backup.
If the primary goes offline for any reason, the backup will automatically takeover as the master if
backup auto switch has been enabled,
virtually no effect to the backup other than a change in the CIA heading, which will change to the
following status. If backup auto switch is disabled, the backup will tell the user that the master has
gone away and will ask if they want the backup to take control of the system.
If you enter the Network>Configure screen, it will have changed to the following.
Your backup is now acting as the master and is controlling the lighting system.
N o t e :
312
See "Backup Auto Switch" on page 297.
If the primary comes back online, it will not retake control of the lighting system.
The primary will wait until it is redesignated as the master and the backup is
reassigned to it.
If at any point you change masters, you must individually reassign any clients to
the new master through the network configure screen.
This happens with
Ion Operations Manual