Try looking thru the LastIPScan section of the tblAssets to see when the if this matches your ping requirements. It's a guess at this point if that holds the values you're looking for.
You'll have to start filtering the report based on your needs.
Select Top 1000000 tblAssets.AssetID,
tblAssets.IPAddress,
tblAssets.LastIPScan,
tblAssets.Lastseen,
tblAssets.Description
From tblAssets