Powerchart - pulling history while not displayed

Ignition
,
1

Not sure if this has always been the case, but was trying to figure out why I was getting higher than expected CPU usage..

View structure:

root
-->Multistate Button
-->FlexContainer1
----->PowerChart
----->Some other content
-->FlexContainer2
----->Table
----->Some other content

I set the display property on the flex containers using the multistate button that allows the user to chose what they want to see.

When I have FlexContainer1 display=False, I expected that the historian wouldn't be getting queried as the PowerChart is no longer displayed either. But it appears it is, as my CPU usage continues to stay quite high (Core Historian).

To verify, I bound the Enable on each of the pens to the FlexContainer1 display property, so that the pens get disabled when the PowerChart isn't on the screen.

Now my CPU tracks with the PowerChart being displayed...

Gateway running 8.3.4

2

That's intentional/just the way it works. The "display" property only changes the frontend visibility of the component - nothing in the backend property model (where the actual tag querying logic happens) pays any attention to it.

It's a reasonable optimization in principle, but changing it automatically might get people upset - if you're running the chart in the background all the time, toggling display is immediate; if we "turned off" the chart in the background automatically it would take longer to show anything useful when you display it again.

3

Sounds good. I just had never noticed before.