Another question on a similar subject.
It sounds like I can probably do this doing a historical tag group as well. Set up the tag group in the basic property section to "Default" (direct, rate of 5,000 ms). In the history property section, set:
- Deadband Mode to Off (don't allow the historian to skip storing unchanged data)
- Sample Mode to Tag Group
- Max Time Between Samples to 0
- Historical Tag Group to an appropriate tag group with a rate of 900,000 ms (15 min * 60 sec/min * 1000 ms/sec).
It looks like we also want to make sure that the Max Time Between Samples is also set to 0 in the Tag Group that we're using for the historical tag group.
Based on @pturmel's post, my impression is that the historical tag group will execute every 15 minutes, grab the current value of the tag, and insert it in the historian.
In theory, this would cause all tags with the same interval to store at the same time, so at least they would be in sync with each other.
Is the above correct/valid? If so, it seems to be a bit more parameters to configure, but keeps all tags with the same Historical Tag Group inserting into the database at the same time (with the potential downside of hammering SQL while doing so).
