Yesterday I created a tag that captures a particular vibration value on an asset being monitored only when it is in a 'running' state. So far so good. The expression is evaluated periodically every 10 seconds.
When I plot the value in PI Vision today for an asset that has been running for the last 24 hours, however I get the below. The fluctuations on the extreme right side (last 10 minutes or so of the plot) are actually what I expected to see but only show up after the chart is displayed over those few minutes. The initial plot is only a handful of points separated by hours over the 1d time range.
Changing the chart range to 1h (or to 1 minute which should clearly show the fluctuating values plotted below) reverts back to a display of only a handful of points over the time rather than a point every 10 seconds as I expect. After waiting the plot begins filling in with the fluctuating values I expect to see.
I imagine this is something obvious but it isn't to me. Suggestions are appreciated.