Scheduler State Service
The ISchedulerStateService interface in the XtraScheduler provides indicators of the current scheduler state.
The ISchedulerStateService.IsDataRefreshAllowed member indicates whether the Scheduler data can be safely reloaded.
You can get the ISchedulerStateService as described in Introduction to Services in XtraScheduler document, use it or substitute with your own custom descendant.
The simplest technique to use the Scheduler State service is to get access to its properties and methods via the SchedulerControl.Services.SchedulerState property wrapper.