Tag Historian Display issue

I'm using tag historian, and found some issues on displaying at webpage. I made a "List" variable in simulator device, rotating 40 random integers (1 to 5) for a duration of 8 hrs, and I purposely made a few exceptional data points 80, recorded one 80 around 7:15pm, and severn 80s around 10pm, and try to verify or understand how ignition historian displays these historian data stored in standard SQL (I guess this is quite different from the proprietary algorithm used in OSI PI), and I found the longer the displaying window range, the more data points would be lost. However, the one 80 around 7:15 would never be lost, and I wonder why? can anyone please explain the mechanism of ignition historian displaying in front end? As my developed application can't lose these exceptional events though very short duration. Any suggestion? thank you





Hi,

When using the Power Chart and modifying the date range to cover a large time span with the chart staying the same size, this behavior is expected. It is trying to fit more data points in the same size chart. When using X-Trace on this Power Chart, are data points that are seemingly being lost for the same tag and timestamp no longer showing a value after modifying the date range?