I have three pens in an easy chart in vision project. When I uncheck two of the three pens the actual values shown on the y axis disappear but I dont have that problem if I have any other of the pen combinations checked/unchecked. I can't figure out why the values disappear..
Image with all three pens selected:
Image with just the last pen selected:
Look in your whichever pens dataset you are using at the 'AXIS' column, and see what is typed there. Make sure the value exactly matches one of the values in the 'NAME' column of the Axes Dataset.
I did. Sometimes it shows up, sometimes not. When certain ones are checked/unchecked it either works or does not work.
When I check/uncheck things when it first loads up I can see the Level for example plus the actual values on the left. After half a second it goes back to what I have shown. Could it be something related to sizing? Scratching my head and can't figure this one out.
I just changed to realtime and now the values show. When I change back to historical the values go away again
A dummy tag that's not user selectable or removable can be put in a chart to make an axis persist even when no tags with that axis are selected. Set its color to match the plot background, and filter out its xtrace label with the extension function, so the user can't tell its there. Just remember that the dummy tag has to be real in the sense that it has to have actual historical values, or it will break the xtrace.
It seems like the axis is showing up correctly, its just the values are not showing up. It almost seems too as if it doesn't show up because the value is not changing. Am I incorrect? So for each easy chart, and for each axis within them, I would have to create dummy variables which could be memory tags and they get saved to the historian just like the other tags? If thats the case it would be a ton of dummy tags I would have to create.
You should only need one. Use the same tag and simply assign it to each axis in multiple rows of the pens dataset. It's not displayed for the user, so it doesn't matter. It's only a placeholder to keep the axes visible when no pens are selected.
Have you tried turning off the AUTO_RANGE parameter in the Axes dataset? Perhaps that is the issue with the tick marks.
Removing the AUTO_RANGE seemed like it would work but I'd have to set the bounds which right now I'm not sure about. Question I had about the dummy tag is does it matter what value it is? If I have auto range enabled would that value throw off everything because the chart needs to take that value into account or will it just ignore that part and just show the actual values I want with auto range turned on?
My original hypothesis was wrong, and you are correct. If auto range is enabled, a static dummy tag will create the same problem you've been observing [because constants don't have a range]. When I've seen a static dummy tag used in the manner I described, it has always been on clearly defined axes such as Temperature (0 to 100), Tank Volume (0 to 10000), etc.
There are several parameters for controlling the auto range behavior in the axes dataset, so it's possible that this behavior could be improved, but at this point, the best approach to achieving the desired result will be to research what the reasonable range should be for the tags, and assign them to an axis with defined bounds.
