save or clear on button press

[chet1]

My program collects a couple points of data on a button press using a state machine. The data are velocity measurements from multiple points along a track - I've got that part working (in the vi attached it's just random numbers so I can tinker with the code without plugging in the hardware).

Each measurement is appended to an array and added to a graph. Oon each button press the data exits the case structure and goes through a for loop with a shift register. Using this array, I am trying to implement two buttons: clear and save. Pressing clear would empty the array and the graph, while pressing save opens a dialog to save the numbers. It almost works! It saves fine, but to clear I have to press "clear" and then "measure" again.

I think my problem lies in how I'm attempting to reinitialize the main array, but after a lot of searching the forums I'm still stuck. I'm not sure if I'm almost there, or if a for loop is the wrong way to go and I need to get rid it altogether?

Thanks for any help!

[JÞB · Accepted solution]

Fairly close.  You forgot that latching booleans need to be in the event case that reads them-  A chart works better than a graph and you never provided for a stop event.  The User interaction is enough to throttle the loop and the wait is not required.

No LAVA CCT here so a snippette would be unusable but I did attach the modified code (Saved to LabVIEW 2011)

[chet1]

Thanks a ton!

[chet1]

Actually it's still not quite there, sorry for being hasty. Now when I press save, only the most recent measurement is saved to disk. How can I make it so every data point showing on the waveform chart can be saved?

[crossrulz]

Just get the chart history instead of using a local variable.  You do that with a property node.  Look in the Clear case, copy that property node, change it to a read and wire it up appropriately.

[JÞB]

Or simply right-click the Local and Change to Property node