We are going to upgrade our DeltaV system from 11.3.1 to 12.3.1 including the flash upgrade of the IO cards.
I'm thinking of decommissioning the VIM controllers and then after we upgrade the DeltaV, we will recommission it back again.
Can someone confirm if this is the right approach? Or we just leave the VIM controllers commissioned while upgrading the DeltaV version & IO cards. Thanks.