How do I use xScale Marker Values to limit the number of points that will show on a scrolling Chart?

[BCharlton44]

http://digital.ni.com/public.nsf/allkb/E9784F413A2269E086256F3A0064C8BB

I am reading in data from a device at various sampling rates. To get a full 5 seconds of data to be seen at the higher sampling rate I need to set the Chart History Length to ~5000. The problem is that I don't want to show that many points for the lowest sampling rate(it would show around 14 seconds of data)

According to that page I can use the "Marker Values" to limit the number of points I use dynamically. The problem is I can't find any documentation on how to use Marker Values to do this proramatically.

Do I pass my data cluster into that instead of the normal "value" property node? How do I define what values I want to show?

[BCharlton44]

so I made a 1D Array with ints set up in the form [(4800-SR*5).....4800] with 4800 being the History Length and SR being the sample rate(hertz).

I pass this array into the WFchart(strict) node property Xscale.MarkerVals[]

nothing happens except the X scale test is now all screwed up. How many data points the chart shows didn't change at all

[BCharlton44]

20 views and not a single person to try and help

great

[Dennis_Knutson]

I for one, am confused as to what you are trying to do with the marker values. If you want to limit the number of points, why don't you set the range.min and range.max?

[BCharlton44]

I have tried and are trying to use the range.min/max again.

I was looking for a soluction and came upon the page in the first post and it seems to be a good solution.

For whatever reason my Range values keep changing even after I set them. I can even not set them dynamically and set them in chat properties and they still won't stay what I set them as. They keep defaulting back to 0.5-34.34 which doesn't make sense to me.

if the history length is 4800 how does a range of 0.5 to 34 still show all the data?

I must be missing something.

[Dennis_Knutson]

Did you turn autoscaling off?

[BCharlton44]

Yes, auto-scale is off

[GoCougs]

It sounds like we will be able to help you much easier if you post your code on here so that we can see what you are trying to do.