So our sales guy* is creating a demo system that runs in a VM on his laptop. Because he doesn’t want/need huge volumes of data he has configured the history to use 5 minute partitions and purge anything older then 15 minutes.
When he went to the trend page it showed data in the future . What it looks like is happening is the last valid point is being duplicated as the last point on the graph so you end up with a flat line from the last good point to the right edge of the graph.
version 7.4.0
*A new tag line: Ignition, control software so easy, sales can use it!
I believe what you’re seeing has been there since 7.3. Basically, it’s as you describe: due to compression, the last value may not be stored for some time. So, it takes the last stored value and projects it to the end of the query… which might go into the future a bit. This projection gets replaced when the real value is stored.
The first thing we should do is only project up until now. Easy enough.
The next thing, that we intend to do for 7.5, is that instead of projecting a flat line, we’ll go grab the current value of the tag (if possible- that is, if the tag is not from a remote system), so that the graph will be accurate, even when data hasn’t been stored yet.
. What it looks like is happening is the last valid point is being duplicated as the last point on the graph so you end up with a flat line from the last good point to the right edge of the graph.