Power chart interpolation fails

Ignition
1

Hi,

When I graph a tag that has lost communication in Ignition, it shows values instead of cutting the graph. For example, during the weekend, we experienced a communication failure with a device, so we didn't record any data (in fact, there are no tables in the database). But when I graph the tag, I get some values displayed. I've noticed that this is due to interpolation, but I can't find how to deactivate it in the power charts.

image
image1408×642 90.3 KB

I've read about converting the inputs to Discrete, but with over 20,000 tags, it becomes a complex task. Is there another way to do it?

Thanks in advance.

2

If this was the case, you wouldn't be recoding anything ever :slight_smile: do you mean there are no records the database historic tables for these points during the comms outage?

To me, the interpolated line should not be there at all if the data is bad. I don't think discrete mode will fix that. I don't know off the top of my head how to fix it :thinking:

3

Personally, this doesn’t look like interpolation, rather it looks like the chart drawing the line between two points.

What is the value of props.pens.display.breakline?

From the manual:

If true, the line will be broken on either side of bad/missing data values. If false, bad/missing data values are removed and the adjoining points are connected.

https://docs.inductiveautomation.com/display/DOC81/Perspective+-+Power+Chart

1 Like
4

You're right