Constant Value DB Trend Pen Display

Ignition
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1

I've got some DB pens on this trend and it's a binary value. Either 0 or 110. How do I get a line to display at all times? Let's say the value changed from 0 to 110 at 11:25 and back to 0 at 12:30. If I'm zoomed in on the trend let's say from 11:30 - 12:00 (i.e. value has not changed in that time) I get essentially nothing on the chart (it looks blank). If I export the chart to excel I can see the one row entry for 110 at 11:25 and that's it. So, why is there no horizontal line across the chart at 110? I use autorange and it puts 110 right in the middle so I can tell it's not 0. If I manually change the range to 0-150 I still see nothing. These are the pen settings:

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image595×571 43 KB

I'm guessing it has something to do with interpolation. Is that not an option with DB tags? I see the option checkbox for Tag History interpolation.

2

Interpolation is not an option for DB tags. You get a plot for whatever your DB supplies. This usually means you need to record often enough to have two points in an possible zoomed in trend window.

3

Is there a way to modify the DB query to always return a value at each end of the window?

4

No. This is a common justification to not use the Power EasyChart, but to use a TimeSeries Classic chart. (You can manipulate the data however you need.) Of course, you should consider a more performant chart component (psssst! Embr!).

5

The screenshot is from Vision :upside_down_face:

6

Topic is also tagged Vision

7

Oops.

Use the Classic Chart with your own named query bindings.