WebIQ: Delay on loading data

[alnapi]

I built a page in which there are both TEXT widgets and LABEL wodgets.

TEXT widgets are linked to an ITEM via the <% = items [0] .value%>, while LABEL widgets are linked to the ITEMs directly.

When I open the page for a moment the data is not displayed, then everything works regularly.

I am attaching a video to help you understand the problem better.
In the page, the left table is made with TEXT, while the left table with LABEL.

Do you have any tips to limit the problem?

[webiq-sk · Accepted solution]

I just rotated the video to be able to see it clearer (attached).

Everything in the WebIQ HMI happens asynchronously like normal in modern web technology. That means that the default widget content is rendered, then the items get subscribed (if they are not already subscribed), then the values (replacers) get replaced as soon as the item values have been received asynchronously from WebIQ.

That's normal behavior with WebIQ. Depending on the speed of the system the browser is running on, the network speed, the network latency, the speed and latency of the PLC and the CPU of the PLC this can be slowed down.

If you do not like this behavior you could hide the tables via a LocalScript in which you subscribe to the same items used in the tables and wait until you have received all of those values in your LocalScript, add a few ms to compensate for browser rendering time and then display the table.

However, I don't see any issues or slow rendering in the video.

[HmiGuide · Accepted solution]

One hint to the 3 different panel types, which influences the seen behaviour.

• Swipe-Panel & Tab-Panel
  Keeps all screens of the group in RAM until you select a different panel group
  Advantage: Displaying a screen the second time it's fast
  Disadvantage: More RAM is used
• Screen
  Removes the screen from RAM when a different screen is displayed
  Advantage: Less RAM is used
  Disadvantage: Displaying a screen take always the same time