LabVIEW Waveform Chart with Small Scale Displays Duplicate Waveform (Ghosting)

Updated Feb 7, 2020

Reported In

Software

  • LabVIEW

Issue Details

When setting a Waveform Chart scale to a small value (~0.001) and writing multiple plots with low sample rates, a duplicate waveform that is slightly out of phase can appear. The behavior is shown below in the following image (with the x-scale being set to a range of 0.01). The Waveform Chart with the small scale (on the left), has a duplicate triangle wave that is out of phase, whereas when the scale is changed to a larger range (chart on the right), the duplicate waveform disappears.


 

Solution

The actual data array does not show any anomalies, and is not affected by the behavior displayed in the Waveform Chart. This is only a cosmetic issue and any calculations performed on the data in the Block Diagram are not affected by the behavior displayed on the Front Panel. To workaround the issue, there are several possibilities. For example, plotting the waveforms to separate Waveform Charts, or increasing the scale range will avoid the issue.