How to show the last 60 seconds of data, in which I get 13080 values, in a chart with a x-scale of -60 to 0?

[snork]

Hi everybody!

I've the following problem:

During 60 seconds of measurement I get 13080 values which I want to display in a rolling chart. The chart shall show the last 60 seconds without changing the X-Axis, that means everytime of the measurement the X-Axis should have a minimum of -60 and a maximum of 0, but the data should roll.
The "Chart History Length..." therefore I set to 13080, but I don't know, if the chart really displays 13080 values in the showing part (from -60 to 0). Does it?
Also I don't know how to fix the X-axis.
Do you understand what I want to do and do you have a solution?

Many thanks,
snork

[ThSa]

Good morning,

first, if you choose history length - 13080 - you will see really 13080 values on the chart...

I've attached a little sample for your problem...
Disable the Auto Scale X Option and set manually the range of the graph to 0 and 60 (or something like that)

I hope it helps...


Thomas Sandrisser

[chilly_charly]

The answer is yes, LV can display 13080 points on a chart (although I'm not sure about the significance of such a display with a 1000 pixel wide chart...)
However, a chart may not be the best tool to answer your question : scale management may create some difficulties (flickering that has to be dealed with using the "defer update" front panel property). If you wish to use a chart, the easiest way to fix the X axis may be to paste a faked scale on the chart control, after hiding the original scale.

The use of a graph could be easier, once you know how to manage the scroll.
Avoid passing the data points to the graph one at a time.

See the attached vi, and ask here for more help if required.

Hope this helps,

CC