Creating a user prompt when a boolean control is first lached but not contiuously showing while it is lached.

[BrownBrown]

Greetings,

I need a boolean control that will write measured data to a text file while it is lached and do nothing while it is unlached (which is simple).  However, I also need it to display a dialog box when it is first lached to prompt the user to either append to an existing file or create a new file.  It should not contiously prompt the user to select new or append while it is lached.  It should only reprompt if the boolean has been unlached and relached.

Any ideas?  I have tried several different approaches but everything that I have done has either not worked at all or contiuously prompts while lached.

I know it will involve a shift register and at least one boolean comparison but I cannot figure out the arrangement.

Thanks in advance.

[GerdW · Accepted solution]

Hi BB,

looked at the Pt-by-Pt functions. There you will find a ready-to-use VI to detect edges of a boolean signal!

Or use that boolean math: RisingEdge = signal[n] AND NOT(signal[n-1]). (Here you need the already mentioned boolean function with a shift register...)

All you need is opening the dialog for rising edges of the boolean signal...

[BrownBrown]

Thanks, GerdW!