Synchronous Call to ECC Using RFC

Hi Experts,

I have a synchronous call from portal to ECC using RFC, wherein the requirement is that by default the call should be going to D92 system but whenever, D92 is down, then as a backup, the RFC call should be going to D70 system. Is it possible to maintain this condition in PI and if yes, then could you please share the approach for this.

Regards,

Deepika Raikode