Bug in Digital Waveform Graph X-Axis

Question

Hello,
I am making separate queried to a database to retrieve analog and digital data over the same time period.  The data were logged at 2 second intervals.  I have verified that both result sets return the same number of values with the same t0 and dt.  I then plot the analog values on an XY Graph and the digital values on a Digital Waveform Graph.  I then use property nodes to sync the two graphs (left and right plot bounds, XScale.Range, and Cursor Position.X).  After doing this, I can see that the datasets do not line up between the two graphs.  The data on the Digital Waveform graph ends several seconds sooner than the analog data.  The x scales of the graphs appear to match but the plots don't align in time.
Has anyone else observed this behavior?  Is there any work-around?
Thank you,
Peter

Answer 1

There is a much simpler way to synchronize these charts. Just use a stacked chart.
If you use a bundle function you can take two signals (almost data type) and wire them into a Waveform Chart together.
Then on the front panel right click on the chart and select Stack Plots
Since you only have 1 X axis now they are instrincly synched and will always write valules at the same time and update the UI together. You can skip all of the scale synching....
Since the data you are working with has lincked time stamps, the data will need to be matched, (make sure the samples are anyched and each itteration both would have the same number of samples.
The last allternative would be to strip the time stamp off of your data then build a new data structure, with the digital data, analog data and 1 set of matched time stamps. You can then plot this on an XY chart using the time stamp for the X axis for both of your other plots.  Let me know if you have other questions.