PI Vision does not allow exporting of all of the tags seen on the PI Vision display, when using the export to csv. It only exports the tag if a value is timestamped within the range of start/end time filters. This is deceiving because on dashboard-type screens, where you only have one value showing up per tag using the "Value symbol", you don't know or care what the timestamp was.
In many cases you have a dashboard full of old and new data-points, but all you care about is the current value for your dashboard. If we export the display to csv, only some tags show up due to the time parameters in the session.
As an example: If you have a tag that shows the time of your last order-change (which was yesterday) and some other process variables that are constantly changing, the export to csv will not even have the time of your last order-change to provide context in Excel (provided your range was set to the default 8 hours... or other range starting later than the timestamp of the tag)
The system should either (A) – always export at least 1 value from all tags on the screen by default, or (B) – provide an option, like a checkbox, when exporting to include (or exclude) all tags that are displayed on the screen. A workaround of changing the time-range in PI Vision is not an option because you still may have some trends on the screen that you need to control the start/end time for, and you may not know the timestamp of the earliest tag.