Hello, I was making a report for some stations and in that, I have to add a history to a tag and show it in a chart. I've created a nested query and I think I've done it correctly, however, I am unable to see the output in the preview window.
I am attaching some screenshots to tell the things I've done.
The Tag History I've created:
The Design Tab for the graph
The preview of the graph
On the right side of the preview pane you can see the XML of your data. When your preview isn’t as expected, it’s always a good idea to start with the data and make sure you have the data you expect for the timeframe you expect. For example, in your last screen shot, your range is just a couple of milliseconds, so double check the data that’s controlling your range and make sure it came back as expected.
So I did a couple of things to verify the things.
Firstly, I checked my Tag History by dropping an Easy Chart on the Screen to see if it records the history or not which it does.
Secondly, I added a new time series chart for the same tag but separate from the nested query so that it doesn't affect the keys and found that it working as well. Also, the range you mentioned in milliseconds is coming just when I add it in the nested query, if I put an individual chart it gives the desired range.
Thirdly, I did what you asked to check the XML of my data and found that it does give me the output values, it's just not showing in the preview.
After that, I dig a little bit for the path for the data keys as mentioned in the nested query video, and used the same path chosen from the search options and got it working now. I'm providing the screenshots of what I did earlier and what I've changed now for the reference.
Earlier:
Now:
