FT Historian Start stop logging

I have a FT Historian system up and running for some time now and it works fine, but I would really like to know if there is a way in PI to start and stop logging based on a tag value? Any help would be great.

Thanks

I don't think what you are asking is possible. There may be a way to turn scan on/off via a VB script, but it takes around 180 seconds for a tag to be placed in the que, and sent to the server. With hard drive space so cheap these days, why not log all the time. It's what we do.
If you have your tag configuration set correctly it will not collect data very often if the tag value does not change.

Thanks for the reply, I kind of figured that was the case, I just wanted to clean things up a bit and logging 100 pts every 100ms just seems silly when the machine only runs 4 hours out of 24 lol.

Take a look at your tag "tuning". When the machine is not running, you should only get a new value every 8 hours or so. Do you have the PI builder add-in for Excel? If you do export all the tags to Excel, review/adjust deltas etc.. and import back in.

Also in PI System Management Tools (SMT), you can go to the data area and use the Archive editor to see how many values are actually being recorded.