Database Tags vs OPC Tags in Easy Chart

I'm setting up an Eazy Chart to monitor Boiler Pressure against Steam Use.

I drag-dropped tags from my OPC Tag Browser but nothing showed up in the chart (for Tag History pens), even though I could see values in the browser.

So I created a historical transaction group and started populating my datatable. I can drop those value columns (Database Pens) into Easy Chart and now I see those data points in Easy Chart.

What am I missing that prevents the Tag History pens from writing in the chart?



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Your Y Column DB Pen name differs with Name of Tag History Pen (maybe something with a tagpath). Can it be the problem?

Some terminology problems/misunderstandings here.

  • The EasyChart plots "Database Pens" and "Historian Pens" and "Calculated Pens". From a database table, from the tag historian, or computed from one or two of those.

  • There's no "OPC Tag Browser". There's a "Tag Browser" and an "OPC Browser". The latter is simply a view into the OPC Items that drivers are exposing for you to make "Tags" from, which would then need to have history turned on or otherwise have values recorded into the database.

Charts need recordings to make plots. They cannot make them out of thin air.

The EasyChart is smart enough to make a plot with drag and drop if the source is the "Tag Browser" and the tag in question has history turned on.


Thanks, everyone for your insights.

Phil, I am using the Tag Browser.

When I was reading the manual for Easy Chart, I noted the three different types of data that could be used. That's why I originally created the TG and then used data from the database to populate the chart.

But then I noticed that I could drag-and-drop tags from the Tag Browser and that's where the issue and confusion arose. If dragging a tag from the browser to the chart doesn't provide any results, why make it possible in the first place?

And then you comment about 'history turned on' made me go back and check and sure enough, History Enabled was off. So now I'm good.

Thanks everyone!

From your latest screenshot, your tags don't have history enabled on them (you'll see a clock icon beside them if they are image). You'll need to enable history in the tag editor for them to start recording history and displaying in the easy chart.

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