You can access and modify data from your waveform chart history using a property node
as shown in this snippet:
You can create an implicit or explicit property node
to the waveform chart and then select History Data
By Right-clicking on the property node, you can choose between read or write by selecting Change All To Read
or Change All To Write
Using a property node in write
mode will allow you to modify the data whereas using a property node in read
mode will allow you to access the data.
As an example, this VI displays two charts, with a linear curve from 0 to 29. The first Waveform Chart history data is modified to replace the 15th data element by 0.
This is the result :