My first thought is that sdrt doesn't display sites that were previously active but currently have no connection - but I would need to test the scenario. I do know that sdrt does not display an offline site that is displayed by Unitrunker 2, but If I deleted that site in Unitruker 2, it would not repopulate until it came back online. I don't know why DSD+ shows site 52 as offline, but sdrt shows it active - probably a difference in refresh rates of the data?