Re: HP SiteScope - What causes the primary SiteScope to go to the Failover?
You are looking at the problem from the wrong end. It's not primary SiteScope that decides when to activate SiteScope Failover. It's SiteScope Failover that monitors health of SiteScope primary and if SiteScope primary becomes unavailable SiteScope Failover activates itself.
Please read SiteScope Failover Guide to get more details on how it works.