if im understanding correctly you could run a scheduled report that overwrites a lookup with the current status. Then you have second report/dashboard that calls that lookup file, thus the oldest data would be the time in between your scheduled searches.
so have scheduled report that runs every 15 minutes or so. That outputs the status of each station like so.
station1, up
station2, down
station3, up
because you are overwriting the lookup on each run the status will always be current and you wont have to manipulate any of the data.
... View more