FOXMAN-UN R18 : Upgrading FOXMAN-UN and FOX61x - Application Note : Upgrade R17A to R18 : FOX61x upgrade : Upgrade via FOXCST : Management Connection to the Active Core Unit
Hitachi Energy
Management Connection to the Active Core Unit
If you are using the local management port of the CESM1, CESM2 or CESM3, make sure that you have the port of the active CESM1, CESM2 or CESM3 connected to your PC.
* 
Please note: 
When doing an ESW download while using CESM1, CESM2 or CESM3 redundancy use the start “Algorithm” parameter “System Release Upgrade”. With “System Release Upgrade”, the system will make sure that core unit in slot 11 will be the active core unit after the upgrade (independent of which unit was active before the upgrade).