You can set up LS performance monitoring for these assets.
Then create report for fresh performance data.
Select Top 1000000 tblassets.AssetID,
tblassets.AssetName,
tblassets.IPAddress,
tblassets.Lastseen,
tblassets.Lasttried,
tblPerformanceCountersScan.ScanDateTime
From tblassets
Inner Join tblPerformanceCountersScan On tblassets.AssetID =
tblPerformanceCountersScan.AssetId
Where tblPerformanceCountersScan.ScanDateTime > GetDate() - '00:30:00'
Then create e-mail send for this report or put on the dashboard.
Performance monitoring has short interval (15 min) so you can get info qiuckly.
IMHO.