How to save waveform image to jpeg file by using button

What part are you having problems with?

1. Get image from the waveform?
2. Save that image?
3. The button to do so?
4. How to name the file?

Typically you want a simple state machine. To define the file name, you can use a file dialog. You might want to do that in a parallel loop using for example an event structure so the dialog does not block the main loop. Create an event for the button change and fire up a file dialog, then grab and save the image. Create an event for the stop button so the parallel loop will also stop at the end.

Also:

• Sorry, I don’t have your drivers, so most of the code I see is broken. Cannot comment on these parts.
• Please don’t maximize the diagram and front panel to the screen.
• Your outer case structure and “start” button makes no sense in terms of dataflow.
• Maybe you want a simple state machine instead.
• You are only showing one element of the LED array, there could be more. Same for CV%.
• Most of your coercion dots could be eliminated by using correct datatypes.
• Don’t hide terminal labels on the block diagram. Give each terminal an intuitive name to keep the code clear (“boolean 2” is not a good name).
• You can eliminate most of your scalar indicators by showing the digital displays of your chart.
• …

I recommend ot look at the shipping examples, design templates and tutorials listed at the top of the forum.