Hi,
which version of LabVIEW DSC are you using? - In LabVIEW DSC 6.0.2 was a bug and should be fixed in the current LabVIEW 6.1.
However, it might be not a bug at all, because...
"This is not necessarily incorrect behavior. The feature should be called MINIMUM time to keep the data. We will eventually reuse the expired data, but after we run out of all available blocks in all existing THD files. So, we always first fill all existing THD files, before reusing expired data.
And even after that. The database is organized in 4k pages. If part of the page contains expired data (from yesterday), while the rest of it contains new data (from today) we cannot reuse the block. The block stays active and all of its data will be available. So, while we guarantee we
don't overwrite the data before the specified time, we don't guarantee we'll discard them immediately."
Hope this helps
Roland