store values from waveform

[Justus Jonas]

Hi everybody,

I have a problem with my waveform. With this VI I want to protocol incoming values over the current time so that I can scroll back the time and see, for example, when a peak happened. What I have is a waveform that has the current time in the X-Axis, but I can’t scroll back.

What I want to know is:

·        How can I store the values for maybe the last 12 hours so that I can scroll back the waveform?

·        If that is possible, can I fill a various beginning time and an end time in a part of the VI (maybe a time stamp control) and the values in this period are shown? (Like scrolling back but just flipping by time entry)

I have a VI that shows it. (The two time stamp controls are blind. (Just to illustrate!))

[manga]

I attached a modified vi that use a chart instead of a graph and an array of data instead of waveform data. It works better but still has problems (you'll see).
My advice is to restart from scratch following this guideline:

1. Initialize an array of data outside the while loop (choos the size that you need)
2. Fill the array with data using 'Replace Array Subset' (keeping track of how much data is in it)
3. At any moment read the chunk of data you want using 'Array Subset' wired to a waveform graph

cheers,
manga