Average value for waveform chart

[Aojha]

Assuming you are taking samples at fix interval let's say 1 sec. for 1 hour then first index is 0 and last will be 3600.

You can corelate your time 0:30 will be index 29 and 0:45 will be 44.

If interval is not fixed and data is coming at any time then you may make an time array for incoming samples and search for index values in this array.

[johnsold]

Oesen,

If you are going to set the chart so that all the data you will be acquiring will be on the chart, then selecting the segment will not have the issue I discussed above.

Setting the scale minimum and maximum does not change the chart history length.  If you are taking one measurement per second, there will 3600 points after 1 hour.  The default chart history length is 1024.  Changing the X Scale Multiplier does not change the history length.  To save all 3600 points you need to change the history length manually.  There does not seem to be a property node for changing the history length.

The attached VI demonstrates this.

Lynn

[Oesen]

Hi johnsold

What if i write the data to a spreadsheet file, and then read the data from that file with a waveform graph, and then find the average value with cursors. Can i use that procedure ?

[johnsold · Accepted solution]

Oesen,

Yes, that should work fine.

Lynn

[Oesen]

Thanks for the help johnsold 🙂