> My program requires the button to have the "Latch until released" > property, so I was wondering if you could tell me a little more about > using a notifier >
The deal is that the latch behavior is defined to reset the button when it is read. The problem is that when more than one location on the diagram reads the button, when does it reset? It could reset on the first read, but that isn't what you want as only one loop would see it. It could reset on a particular read, it could reset after all of the places have read it, but what if one of the loops reads it N times before the other loop reads it? To "fix" this, LV requires you, the programmer to determine what behavior you want and reset the button yourself using a write local variable. If you know how your loops run, or if they are synchronized, you can choose one to read and the other to read and reset. Be careful here that you don't write a program that drops the button and doesn't let one loop see it. The other suggestion was to use a notifier. This means that the button belongs to one loop, and is read and latched by that loop. The other loop instead reads from a notifier object in LV. The loop that owns the button sets the notifier when it sees the button toggle. The notifiers are located in the Advanced/Synchronization palette, and there are some examples of their use in the examples/general/notifier.llb, but they may not help that much. You might be better off just reading about them in the manual. Greg McKaskle
