Axiom Chart - Break in Data isn't reflected in Chart Data
I have a situation where we had a power outage for about 3.5 hours and when looking at the chart data, the unchanged data is what is shown in the charts during this power outage.
If I look at the data's WorstQuality (which I overlayed for visibility) I can see there is no valid data within that time.
Is it possible to have the chart data not show a data-line where the quality is not 192 (or alter the line type) during this window?
Regards,
Canary 25.3 with Windows Server 2025
8 replies
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What collector are you using collect this data? OPC DA? UA?
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Hi ,
Assuming you're using our Canary Historian module for Ignition to collect the data, it currently doesn't have a way to log these outages with a NoData. I created a request to add this functionality that would log a NoData if/when the logging session terminates which would occur if the module or gateway went down.
In the meantime, if you wanted to create a gap in the data, the easiest way would be to use the Write API and insert a NoData value one tick after the 3:08:02.169 PM timestamp.-
Yes we are using the Canary Module on our Ignition Gateway. There are nearly 2200 tags that would need to be written to in that window/tick. But when I look at the quality it's already noting "NoData" with a quality value of 0x8000.
or are you thinking of changing the actual data that is present to "noData"?
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I was basing this off of your first screenshot of the Historian. I didn't see a NoData listed. But now I see that the screenshot of Axiom is not the same tag. So you have some tags that show the gap and others that do not? If a tag has a NoData quality value, that would appear as a gap on the chart as it is considered a Bad quality.
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It's the same tag, but one trend is looking at the TimeData and the other is looking at the WorstQuality of the same tag.
This is just 1 tag as an example. but all tags in the DB have the same issue. -
Ok. I think the gap that appears with the WorstQuality is just the nature of how that aggregate is drawn. If you use WorstQuality2, I don't think that gap would appear. The "NoData 0x8000" value appears in this case because there is nothing to draw, but it can also appear if there is an actual "NoData 0x8000" quality value stored in the Historian as seen here:
I would go back to my original suggestion and say if you want to reflect a gap in the actual data, regardless of the aggregate used to draw it, you could insert a NoData quality value (pictured above) one ticket after the last good value before it flat-lined. Right now, it assumes the value is good until the next Good quality value at 6:42:35.792 PM.
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This topic has escalated a bit for us. After starting to review this further over the last month, we are seeing that some data is being dropped for a period of time while just running.
One of the Engineers has started to log some of the "Worst Quality" values for some of their data and are realizing there are a lot of breaks in the data when the system is operating. See attached screenshot.
All the tags are being pulled from the same Ignition Gateway.
Yvon
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